Commit Graph

40451 Commits

Author SHA1 Message Date
Masami Hiramatsu (Google)
40adaf51cb tracing/eprobe: Fix eprobe filter to make a filter correctly
Since the eprobe filter was defined based on the eprobe's trace event
itself, it doesn't work correctly. Use the original trace event of
the eprobe when making the filter so that the filter works correctly.

Without this fix:

 # echo 'e syscalls/sys_enter_openat \
	flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
 # echo 1 > events/eprobes/sys_enter_openat/enable
[  114.551550] event trace: Could not enable event sys_enter_openat
-bash: echo: write error: Invalid argument

With this fix:
 # echo 'e syscalls/sys_enter_openat \
	flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
 # echo 1 > events/eprobes/sys_enter_openat/enable
 # tail trace
cat-241     [000] ...1.   266.498449: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0
cat-242     [000] ...1.   266.977640: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0

Link: https://lore.kernel.org/all/166823166395.1385292.8931770640212414483.stgit@devnote3/

Fixes: 752be5c5c9 ("tracing/eprobe: Add eprobe filter support")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Tested-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Rafael Mendonca
342a4a2f99 tracing/eprobe: Fix warning in filter creation
The filter pointer (filterp) passed to create_filter() function must be a
pointer that references a NULL pointer, otherwise, we get a warning when
adding a filter option to the event probe:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \
        runtime=$runtime:u32 if cpu < 4' >> dynamic_events
[ 5034.340439] ------------[ cut here ]------------
[ 5034.341258] WARNING: CPU: 0 PID: 223 at kernel/trace/trace_events_filter.c:1939 create_filter+0x1db/0x250
[...] stripped
[ 5034.345518] RIP: 0010:create_filter+0x1db/0x250
[...] stripped
[ 5034.351604] Call Trace:
[ 5034.351803]  <TASK>
[ 5034.351959]  ? process_preds+0x1b40/0x1b40
[ 5034.352241]  ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.352604]  ? kasan_set_track+0x29/0x40
[ 5034.352904]  ? kasan_save_alloc_info+0x1f/0x30
[ 5034.353264]  create_event_filter+0x38/0x50
[ 5034.353573]  __trace_eprobe_create+0x16f4/0x1d20
[ 5034.353964]  ? eprobe_dyn_event_release+0x360/0x360
[ 5034.354363]  ? mark_held_locks+0xa6/0xf0
[ 5034.354684]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355105]  ? trace_hardirqs_on+0x41/0x120
[ 5034.355417]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355751]  ? __create_object+0x5b7/0xcf0
[ 5034.356027]  ? lock_is_held_type+0xaf/0x120
[ 5034.356362]  ? rcu_read_lock_bh_held+0xb0/0xd0
[ 5034.356716]  ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.357084]  ? kasan_set_track+0x29/0x40
[ 5034.357411]  ? kasan_save_alloc_info+0x1f/0x30
[ 5034.357715]  ? __kasan_kmalloc+0xb8/0xc0
[ 5034.357985]  ? write_comp_data+0x2f/0x90
[ 5034.358302]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.358691]  ? argv_split+0x381/0x460
[ 5034.358949]  ? write_comp_data+0x2f/0x90
[ 5034.359240]  ? eprobe_dyn_event_release+0x360/0x360
[ 5034.359620]  trace_probe_create+0xf6/0x110
[ 5034.359940]  ? trace_probe_match_command_args+0x240/0x240
[ 5034.360376]  eprobe_dyn_event_create+0x21/0x30
[ 5034.360709]  create_dyn_event+0xf3/0x1a0
[ 5034.360983]  trace_parse_run_command+0x1a9/0x2e0
[ 5034.361297]  ? dyn_event_release+0x500/0x500
[ 5034.361591]  dyn_event_write+0x39/0x50
[ 5034.361851]  vfs_write+0x311/0xe50
[ 5034.362091]  ? dyn_event_seq_next+0x40/0x40
[ 5034.362376]  ? kernel_write+0x5b0/0x5b0
[ 5034.362637]  ? write_comp_data+0x2f/0x90
[ 5034.362937]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.363258]  ? ftrace_syscall_enter+0x544/0x840
[ 5034.363563]  ? write_comp_data+0x2f/0x90
[ 5034.363837]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.364156]  ? write_comp_data+0x2f/0x90
[ 5034.364468]  ? write_comp_data+0x2f/0x90
[ 5034.364770]  ksys_write+0x158/0x2a0
[ 5034.365022]  ? __ia32_sys_read+0xc0/0xc0
[ 5034.365344]  __x64_sys_write+0x7c/0xc0
[ 5034.365669]  ? syscall_enter_from_user_mode+0x53/0x70
[ 5034.366084]  do_syscall_64+0x60/0x90
[ 5034.366356]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 5034.366767] RIP: 0033:0x7ff0b43938f3
[...] stripped
[ 5034.371892]  </TASK>
[ 5034.374720] ---[ end trace 0000000000000000 ]---

Link: https://lore.kernel.org/all/20221108202148.1020111-1-rafaelmendsr@gmail.com/

Fixes: 752be5c5c9 ("tracing/eprobe: Add eprobe filter support")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Li Huafei
5dd7caf0bd kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case
In __unregister_kprobe_top(), if the currently unregistered probe has
post_handler but other child probes of the aggrprobe do not have
post_handler, the post_handler of the aggrprobe is cleared. If this is
a ftrace-based probe, there is a problem. In later calls to
disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is
NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in
__disarm_kprobe_ftrace() and may even cause use-after-free:

  Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)
  WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0
  Modules linked in: testKprobe_007(-)
  CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18
  [...]
  Call Trace:
   <TASK>
   __disable_kprobe+0xcd/0xe0
   __unregister_kprobe_top+0x12/0x150
   ? mutex_lock+0xe/0x30
   unregister_kprobes.part.23+0x31/0xa0
   unregister_kprobe+0x32/0x40
   __x64_sys_delete_module+0x15e/0x260
   ? do_user_addr_fault+0x2cd/0x6b0
   do_syscall_64+0x3a/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   [...]

For the kprobe-on-ftrace case, we keep the post_handler setting to
identify this aggrprobe armed with kprobe_ipmodify_ops. This way we
can disarm it correctly.

Link: https://lore.kernel.org/all/20221112070000.35299-1-lihuafei1@huawei.com/

Fixes: 0bc11ed5ab ("kprobes: Allow kprobes coexist with livepatch")
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Yi Yang
0a1ebe35cb rethook: fix a potential memleak in rethook_alloc()
In rethook_alloc(), the variable rh is not freed or passed out
if handler is NULL, which could lead to a memleak, fix it.

Link: https://lore.kernel.org/all/20221110104438.88099-1-yiyang13@huawei.com/
[Masami: Add "rethook:" tag to the title.]

Fixes: 54ecbe6f1e ("rethook: Add a generic return hook")
Cc: stable@vger.kernel.org
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Acke-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Rafael Mendonca
d1776c0202 tracing/eprobe: Fix memory leak of filter string
The filter string doesn't get freed when a dynamic event is deleted. If a
filter is set, then memory is leaked:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
root@localhost:/sys/kernel/tracing# echo "-:egroup/stat_runtime_4core"  >> dynamic_events
root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak
[  224.416373] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88810156f1b8 (size 8):
  comm "bash", pid 224, jiffies 4294935612 (age 55.800s)
  hex dump (first 8 bytes):
    63 70 75 20 3c 20 34 00                          cpu < 4.
  backtrace:
    [<000000009f880725>] __kmem_cache_alloc_node+0x18e/0x720
    [<0000000042492946>] __kmalloc+0x57/0x240
    [<0000000034ea7995>] __trace_eprobe_create+0x1214/0x1d30
    [<00000000d70ef730>] trace_probe_create+0xf6/0x110
    [<00000000915c7b16>] eprobe_dyn_event_create+0x21/0x30
    [<000000000d894386>] create_dyn_event+0xf3/0x1a0
    [<00000000e9af57d5>] trace_parse_run_command+0x1a9/0x2e0
    [<0000000080777f18>] dyn_event_write+0x39/0x50
    [<0000000089f0ec73>] vfs_write+0x311/0xe50
    [<000000003da1bdda>] ksys_write+0x158/0x2a0
    [<00000000bb1e616e>] __x64_sys_write+0x7c/0xc0
    [<00000000e8aef1f7>] do_syscall_64+0x60/0x90
    [<00000000fe7fe8ba>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Additionally, in __trace_eprobe_create() function, if an error occurs after
the call to trace_eprobe_parse_filter(), which allocates the filter string,
then memory is also leaked. That can be reproduced by creating the same
event probe twice:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
-bash: echo: write error: File exists
root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak
[  207.871584] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8881020d17a8 (size 8):
  comm "bash", pid 223, jiffies 4294938308 (age 31.000s)
  hex dump (first 8 bytes):
    63 70 75 20 3c 20 34 00                          cpu < 4.
  backtrace:
    [<000000000e4f5f31>] __kmem_cache_alloc_node+0x18e/0x720
    [<0000000024f0534b>] __kmalloc+0x57/0x240
    [<000000002930a28e>] __trace_eprobe_create+0x1214/0x1d30
    [<0000000028387903>] trace_probe_create+0xf6/0x110
    [<00000000a80d6a9f>] eprobe_dyn_event_create+0x21/0x30
    [<000000007168698c>] create_dyn_event+0xf3/0x1a0
    [<00000000f036bf6a>] trace_parse_run_command+0x1a9/0x2e0
    [<00000000014bde8b>] dyn_event_write+0x39/0x50
    [<0000000078a097f7>] vfs_write+0x311/0xe50
    [<00000000996cb208>] ksys_write+0x158/0x2a0
    [<00000000a3c2acb0>] __x64_sys_write+0x7c/0xc0
    [<0000000006b5d698>] do_syscall_64+0x60/0x90
    [<00000000780e8ecf>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fix both issues by releasing the filter string in
trace_event_probe_cleanup().

Link: https://lore.kernel.org/all/20221108235738.1021467-1-rafaelmendsr@gmail.com/

Fixes: 752be5c5c9 ("tracing/eprobe: Add eprobe filter support")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Shang XiaoJing
22ea4ca963 tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()
When test_gen_kprobe_cmd() failed after kprobe_event_gen_cmd_end(), it
will goto delete, which will call kprobe_event_delete() and release the
corresponding resource. However, the trace_array in gen_kretprobe_test
will point to the invalid resource. Set gen_kretprobe_test to NULL
after called kprobe_event_delete() to prevent null-ptr-deref.

BUG: kernel NULL pointer dereference, address: 0000000000000070
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 246 Comm: modprobe Tainted: G        W
6.1.0-rc1-00174-g9522dc5c87da-dirty #248
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:__ftrace_set_clr_event_nolock+0x53/0x1b0
Code: e8 82 26 fc ff 49 8b 1e c7 44 24 0c ea ff ff ff 49 39 de 0f 84 3c
01 00 00 c7 44 24 18 00 00 00 00 e8 61 26 fc ff 48 8b 6b 10 <44> 8b 65
70 4c 8b 6d 18 41 f7 c4 00 02 00 00 75 2f
RSP: 0018:ffffc9000159fe00 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88810971d268 RCX: 0000000000000000
RDX: ffff8881080be600 RSI: ffffffff811b48ff RDI: ffff88810971d058
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc9000159fe58 R11: 0000000000000001 R12: ffffffffa0001064
R13: ffffffffa000106c R14: ffff88810971d238 R15: 0000000000000000
FS:  00007f89eeff6540(0000) GS:ffff88813b600000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000070 CR3: 000000010599e004 CR4: 0000000000330ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __ftrace_set_clr_event+0x3e/0x60
 trace_array_set_clr_event+0x35/0x50
 ? 0xffffffffa0000000
 kprobe_event_gen_test_exit+0xcd/0x10b [kprobe_event_gen_test]
 __x64_sys_delete_module+0x206/0x380
 ? lockdep_hardirqs_on_prepare+0xd8/0x190
 ? syscall_enter_from_user_mode+0x1c/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f89eeb061b7

Link: https://lore.kernel.org/all/20221108015130.28326-3-shangxiaojing@huawei.com/

Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:34 +09:00
Shang XiaoJing
e0d75267f5 tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()
When trace_get_event_file() failed, gen_kretprobe_test will be assigned
as the error code. If module kprobe_event_gen_test is removed now, the
null pointer dereference will happen in kprobe_event_gen_test_exit().
Check if gen_kprobe_test or gen_kretprobe_test is error code or NULL
before dereference them.

BUG: kernel NULL pointer dereference, address: 0000000000000012
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 3 PID: 2210 Comm: modprobe Not tainted
6.1.0-rc1-00171-g2159299a3b74-dirty #217
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:kprobe_event_gen_test_exit+0x1c/0xb5 [kprobe_event_gen_test]
Code: Unable to access opcode bytes at 0xffffffff9ffffff2.
RSP: 0018:ffffc900015bfeb8 EFLAGS: 00010246
RAX: ffffffffffffffea RBX: ffffffffa0002080 RCX: 0000000000000000
RDX: ffffffffa0001054 RSI: ffffffffa0001064 RDI: ffffffffdfc6349c
RBP: ffffffffa0000000 R08: 0000000000000004 R09: 00000000001e95c0
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000800
R13: ffffffffa0002420 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f56b75be540(0000) GS:ffff88813bc00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff9ffffff2 CR3: 000000010874a006 CR4: 0000000000330ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __x64_sys_delete_module+0x206/0x380
 ? lockdep_hardirqs_on_prepare+0xd8/0x190
 ? syscall_enter_from_user_mode+0x1c/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lore.kernel.org/all/20221108015130.28326-2-shangxiaojing@huawei.com/

Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-11-18 10:15:33 +09:00
Shang XiaoJing
1b5f1c34d3 tracing: Fix wild-memory-access in register_synth_event()
In register_synth_event(), if set_synth_event_print_fmt() failed, then
both trace_remove_event_call() and unregister_trace_event() will be
called, which means the trace_event_call will call
__unregister_trace_event() twice. As the result, the second unregister
will causes the wild-memory-access.

register_synth_event
    set_synth_event_print_fmt failed
    trace_remove_event_call
        event_remove
            if call->event.funcs then
            __unregister_trace_event (first call)
    unregister_trace_event
        __unregister_trace_event (second call)

Fix the bug by avoiding to call the second __unregister_trace_event() by
checking if the first one is called.

general protection fault, probably for non-canonical address
	0xfbd59c0000000024: 0000 [#1] SMP KASAN PTI
KASAN: maybe wild-memory-access in range
[0xdead000000000120-0xdead000000000127]
CPU: 0 PID: 3807 Comm: modprobe Not tainted
6.1.0-rc1-00186-g76f33a7eedb4 #299
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:unregister_trace_event+0x6e/0x280
Code: 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 0e 02 00 00 48
b8 00 00 00 00 00 fc ff df 4c 8b 63 08 4c 89 e2 48 c1 ea 03 <80> 3c 02
00 0f 85 e2 01 00 00 49 89 2c 24 48 85 ed 74 28 e8 7a 9b
RSP: 0018:ffff88810413f370 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffff888105d050b0 RCX: 0000000000000000
RDX: 1bd5a00000000024 RSI: ffff888119e276e0 RDI: ffffffff835a8b20
RBP: dead000000000100 R08: 0000000000000000 R09: fffffbfff0913481
R10: ffffffff8489a407 R11: fffffbfff0913480 R12: dead000000000122
R13: ffff888105d050b8 R14: 0000000000000000 R15: ffff888105d05028
FS:  00007f7823e8d540(0000) GS:ffff888119e00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7823e7ebec CR3: 000000010a058002 CR4: 0000000000330ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __create_synth_event+0x1e37/0x1eb0
 create_or_delete_synth_event+0x110/0x250
 synth_event_run_command+0x2f/0x110
 test_gen_synth_cmd+0x170/0x2eb [synth_event_gen_test]
 synth_event_gen_test_init+0x76/0x9bc [synth_event_gen_test]
 do_one_initcall+0xdb/0x480
 do_init_module+0x1cf/0x680
 load_module+0x6a50/0x70a0
 __do_sys_finit_module+0x12f/0x1c0
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lkml.kernel.org/r/20221117012346.22647-3-shangxiaojing@huawei.com

Fixes: 4b147936fa ("tracing: Add support for 'synthetic' events")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 18:24:58 -05:00
Shang XiaoJing
a4527fef9a tracing: Fix memory leak in test_gen_synth_cmd() and test_empty_synth_event()
test_gen_synth_cmd() only free buf in fail path, hence buf will leak
when there is no failure. Add kfree(buf) to prevent the memleak. The
same reason and solution in test_empty_synth_event().

unreferenced object 0xffff8881127de000 (size 2048):
  comm "modprobe", pid 247, jiffies 4294972316 (age 78.756s)
  hex dump (first 32 bytes):
    20 67 65 6e 5f 73 79 6e 74 68 5f 74 65 73 74 20   gen_synth_test
    20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69 64 5f   pid_t next_pid_
  backtrace:
    [<000000004254801a>] kmalloc_trace+0x26/0x100
    [<0000000039eb1cf5>] 0xffffffffa00083cd
    [<000000000e8c3bc8>] 0xffffffffa00086ba
    [<00000000c293d1ea>] do_one_initcall+0xdb/0x480
    [<00000000aa189e6d>] do_init_module+0x1cf/0x680
    [<00000000d513222b>] load_module+0x6a50/0x70a0
    [<000000001fd4d529>] __do_sys_finit_module+0x12f/0x1c0
    [<00000000b36c4c0f>] do_syscall_64+0x3f/0x90
    [<00000000bbf20cf3>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
unreferenced object 0xffff8881127df000 (size 2048):
  comm "modprobe", pid 247, jiffies 4294972324 (age 78.728s)
  hex dump (first 32 bytes):
    20 65 6d 70 74 79 5f 73 79 6e 74 68 5f 74 65 73   empty_synth_tes
    74 20 20 70 69 64 5f 74 20 6e 65 78 74 5f 70 69  t  pid_t next_pi
  backtrace:
    [<000000004254801a>] kmalloc_trace+0x26/0x100
    [<00000000d4db9a3d>] 0xffffffffa0008071
    [<00000000c31354a5>] 0xffffffffa00086ce
    [<00000000c293d1ea>] do_one_initcall+0xdb/0x480
    [<00000000aa189e6d>] do_init_module+0x1cf/0x680
    [<00000000d513222b>] load_module+0x6a50/0x70a0
    [<000000001fd4d529>] __do_sys_finit_module+0x12f/0x1c0
    [<00000000b36c4c0f>] do_syscall_64+0x3f/0x90
    [<00000000bbf20cf3>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lkml.kernel.org/r/20221117012346.22647-2-shangxiaojing@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: <fengguang.wu@intel.com>
Cc: stable@vger.kernel.org
Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 17:51:38 -05:00
Xiu Jianfeng
19ba6c8af9 ftrace: Fix null pointer dereference in ftrace_add_mod()
The @ftrace_mod is allocated by kzalloc(), so both the members {prev,next}
of @ftrace_mode->list are NULL, it's not a valid state to call list_del().
If kstrdup() for @ftrace_mod->{func|module} fails, it goes to @out_free
tag and calls free_ftrace_mod() to destroy @ftrace_mod, then list_del()
will write prev->next and next->prev, where null pointer dereference
happens.

BUG: kernel NULL pointer dereference, address: 0000000000000008
Oops: 0002 [#1] PREEMPT SMP NOPTI
Call Trace:
 <TASK>
 ftrace_mod_callback+0x20d/0x220
 ? do_filp_open+0xd9/0x140
 ftrace_process_regex.isra.51+0xbf/0x130
 ftrace_regex_write.isra.52.part.53+0x6e/0x90
 vfs_write+0xee/0x3a0
 ? __audit_filter_op+0xb1/0x100
 ? auditd_test_task+0x38/0x50
 ksys_write+0xa5/0xe0
 do_syscall_64+0x3a/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Kernel panic - not syncing: Fatal exception

So call INIT_LIST_HEAD() to initialize the list member to fix this issue.

Link: https://lkml.kernel.org/r/20221116015207.30858-1-xiujianfeng@huawei.com

Cc: stable@vger.kernel.org
Fixes: 673feb9d76 ("ftrace: Add :mod: caching infrastructure to trace_array")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 17:16:44 -05:00
Daniil Tatianin
56f4ca0a79 ring_buffer: Do not deactivate non-existant pages
rb_head_page_deactivate() expects cpu_buffer to contain a valid list of
->pages, so verify that the list is actually present before calling it.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru

Cc: stable@vger.kernel.org
Fixes: 77ae365eca ("ring-buffer: make lockless")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 17:10:40 -05:00
Wang Wensheng
bcea02b096 ftrace: Optimize the allocation for mcount entries
If we can't allocate this size, try something smaller with half of the
size. Its order should be decreased by one instead of divided by two.

Link: https://lkml.kernel.org/r/20221109094434.84046-3-wangwensheng4@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: a790087554 ("ftrace: Allocate the mcount record pages as groups")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 15:42:48 -05:00
Wang Wensheng
08948caebe ftrace: Fix the possible incorrect kernel message
If the number of mcount entries is an integer multiple of
ENTRIES_PER_PAGE, the page count showing on the console would be wrong.

Link: https://lkml.kernel.org/r/20221109094434.84046-2-wangwensheng4@huawei.com

Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: 5821e1b74f ("function tracing: fix wrong pos computing when read buffer has been fulfilled")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-17 15:41:31 -05:00
Hou Tao
3af43ba4c6 bpf: Pass map file to .map_update_batch directly
Currently bpf_map_do_batch() first invokes fdget(batch.map_fd) to get
the target map file, then it invokes generic_map_update_batch() to do
batch update. generic_map_update_batch() will get the target map file
by using fdget(batch.map_fd) again and pass it to bpf_map_update_value().

The problem is map file returned by the second fdget() may be NULL or a
totally different file compared by map file in bpf_map_do_batch(). The
reason is that the first fdget() only guarantees the liveness of struct
file instead of file descriptor and the file description may be released
by concurrent close() through pick_file().

It doesn't incur any problem as for now, because maps with batch update
support don't use map file in .map_fd_get_ptr() ops. But it is better to
fix the potential access of an invalid map file.

Using __bpf_map_get() again in generic_map_update_batch() can not fix
the problem, because batch.map_fd may be closed and reopened, and the
returned map file may be different with map file got in
bpf_map_do_batch(), so just passing the map file directly to
.map_update_batch() in bpf_map_do_batch().

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221116075059.1551277-1-houtao@huaweicloud.com
2022-11-17 17:12:35 +01:00
Wang Yufen
649e72070c tracing: Fix memory leak in tracing_read_pipe()
kmemleak reports this issue:

unreferenced object 0xffff888105a18900 (size 128):
  comm "test_progs", pid 18933, jiffies 4336275356 (age 22801.766s)
  hex dump (first 32 bytes):
    25 73 00 90 81 88 ff ff 26 05 00 00 42 01 58 04  %s......&...B.X.
    03 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000560143a1>] __kmalloc_node_track_caller+0x4a/0x140
    [<000000006af00822>] krealloc+0x8d/0xf0
    [<00000000c309be6a>] trace_iter_expand_format+0x99/0x150
    [<000000005a53bdb6>] trace_check_vprintf+0x1e0/0x11d0
    [<0000000065629d9d>] trace_event_printf+0xb6/0xf0
    [<000000009a690dc7>] trace_raw_output_bpf_trace_printk+0x89/0xc0
    [<00000000d22db172>] print_trace_line+0x73c/0x1480
    [<00000000cdba76ba>] tracing_read_pipe+0x45c/0x9f0
    [<0000000015b58459>] vfs_read+0x17b/0x7c0
    [<000000004aeee8ed>] ksys_read+0xed/0x1c0
    [<0000000063d3d898>] do_syscall_64+0x3b/0x90
    [<00000000a06dda7f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

iter->fmt alloced in
  tracing_read_pipe() -> .. ->trace_iter_expand_format(), but not
freed, to fix, add free in tracing_release_pipe()

Link: https://lkml.kernel.org/r/1667819090-4643-1-git-send-email-wangyufen@huawei.com

Cc: stable@vger.kernel.org
Fixes: efbbdaa22b ("tracing: Show real address for trace event arguments")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-16 20:29:00 -05:00
Steven Rostedt (Google)
31029a8b2c ring-buffer: Include dropped pages in counting dirty patches
The function ring_buffer_nr_dirty_pages() was created to find out how many
pages are filled in the ring buffer. There's two running counters. One is
incremented whenever a new page is touched (pages_touched) and the other
is whenever a page is read (pages_read). The dirty count is the number
touched minus the number read. This is used to determine if a blocked task
should be woken up if the percentage of the ring buffer it is waiting for
is hit.

The problem is that it does not take into account dropped pages (when the
new writes overwrite pages that were not read). And then the dirty pages
will always be greater than the percentage.

This makes the "buffer_percent" file inaccurate, as the number of dirty
pages end up always being larger than the percentage, event when it's not
and this causes user space to be woken up more than it wants to be.

Add a new counter to keep track of lost pages, and include that in the
accounting of dirty pages so that it is actually accurate.

Link: https://lkml.kernel.org/r/20221021123013.55fb6055@gandalf.local.home

Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-16 18:08:29 -05:00
Steven Rostedt (Google)
42fb0a1e84 tracing/ring-buffer: Have polling block on watermark
Currently the way polling works on the ring buffer is broken. It will
return immediately if there's any data in the ring buffer whereas a read
will block until the watermark (defined by the tracefs buffer_percent file)
is hit.

That is, a select() or poll() will return as if there's data available,
but then the following read will block. This is broken for the way
select()s and poll()s are supposed to work.

Have the polling on the ring buffer also block the same way reads and
splice does on the ring buffer.

Link: https://lkml.kernel.org/r/20221020231427.41be3f26@gandalf.local.home

Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Primiano Tucci <primiano@google.com>
Cc: stable@vger.kernel.org
Fixes: 1e0d6714ac ("ring-buffer: Do not wake up a splice waiter when page is not full")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-11-16 17:13:04 -05:00
Eduard Zingerman
befae75856 bpf: propagate nullness information for reg to reg comparisons
Propagate nullness information for branches of register to register
equality compare instructions. The following rules are used:
- suppose register A maybe null
- suppose register B is not null
- for JNE A, B, ... - A is not null in the false branch
- for JEQ A, B, ... - A is not null in the true branch

E.g. for program like below:

  r6 = skb->sk;
  r7 = sk_fullsock(r6);
  r0 = sk_fullsock(r6);
  if (r0 == 0) return 0;    (a)
  if (r0 != r7) return 0;   (b)
  *r7->type;                (c)
  return 0;

It is safe to dereference r7 at point (c), because of (a) and (b).

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221115224859.2452988-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-15 17:38:36 -08:00
Toke Høiland-Jørgensen
32637e3300 bpf: Expand map key argument of bpf_redirect_map to u64
For queueing packets in XDP we want to add a new redirect map type with
support for 64-bit indexes. To prepare fore this, expand the width of the
'key' argument to the bpf_redirect_map() helper. Since BPF registers are
always 64-bit, this should be safe to do after the fact.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20221108140601.149971-3-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-15 09:00:27 -08:00
Hou Tao
47df8a2f78 bpf, perf: Use subprog name when reporting subprog ksymbol
Since commit bfea9a8574 ("bpf: Add name to struct bpf_ksym"), when
reporting subprog ksymbol to perf, prog name instead of subprog name is
used. The backtrace of bpf program with subprogs will be incorrect as
shown below:

  ffffffffc02deace bpf_prog_e44a3057dcb151f8_overwrite+0x66
  ffffffffc02de9f7 bpf_prog_e44a3057dcb151f8_overwrite+0x9f
  ffffffffa71d8d4e trace_call_bpf+0xce
  ffffffffa71c2938 perf_call_bpf_enter.isra.0+0x48

overwrite is the entry program and it invokes the overwrite_htab subprog
through bpf_loop, but in above backtrace, overwrite program just jumps
inside itself.

Fixing it by using subprog name when reporting subprog ksymbol. After
the fix, the output of perf script will be correct as shown below:

  ffffffffc031aad2 bpf_prog_37c0bec7d7c764a4_overwrite_htab+0x66
  ffffffffc031a9e7 bpf_prog_c7eb827ef4f23e71_overwrite+0x9f
  ffffffffa3dd8d4e trace_call_bpf+0xce
  ffffffffa3dc2938 perf_call_bpf_enter.isra.0+0x48

Fixes: bfea9a8574 ("bpf: Add name to struct bpf_ksym")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20221114095733.158588-1-houtao@huaweicloud.com
2022-11-15 15:36:57 +01:00
Kumar Kartikeya Dwivedi
6728aea721 bpf: Refactor btf_struct_access
Instead of having to pass multiple arguments that describe the register,
pass the bpf_reg_state into the btf_struct_access callback. Currently,
all call sites simply reuse the btf and btf_id of the reg they want to
check the access of. The only exception to this pattern is the callsite
in check_ptr_to_map_access, hence for that case create a dummy reg to
simulate PTR_TO_BTF_ID access.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14 21:52:45 -08:00
Kumar Kartikeya Dwivedi
894f2a8b16 bpf: Rename MEM_ALLOC to MEM_RINGBUF
Currently, verifier uses MEM_ALLOC type tag to specially tag memory
returned from bpf_ringbuf_reserve helper. However, this is currently
only used for this purpose and there is an implicit assumption that it
only refers to ringbuf memory (e.g. the check for ARG_PTR_TO_ALLOC_MEM
in check_func_arg_reg_off).

Hence, rename MEM_ALLOC to MEM_RINGBUF to indicate this special
relationship and instead open the use of MEM_ALLOC for more generic
allocations made for user types.

Also, since ARG_PTR_TO_ALLOC_MEM_OR_NULL is unused, simply drop it.

Finally, update selftests using 'alloc_' verifier string to 'ringbuf_'.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14 21:52:45 -08:00
Kumar Kartikeya Dwivedi
2de2669b4e bpf: Rename RET_PTR_TO_ALLOC_MEM
Currently, the verifier has two return types, RET_PTR_TO_ALLOC_MEM, and
RET_PTR_TO_ALLOC_MEM_OR_NULL, however the former is confusingly named to
imply that it carries MEM_ALLOC, while only the latter does. This causes
confusion during code review leading to conclusions like that the return
value of RET_PTR_TO_DYNPTR_MEM_OR_NULL (which is RET_PTR_TO_ALLOC_MEM |
PTR_MAYBE_NULL) may be consumable by bpf_ringbuf_{submit,commit}.

Rename it to make it clear MEM_ALLOC needs to be tacked on top of
RET_PTR_TO_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14 21:52:45 -08:00
Kumar Kartikeya Dwivedi
f0c5941ff5 bpf: Support bpf_list_head in map values
Add the support on the map side to parse, recognize, verify, and build
metadata table for a new special field of the type struct bpf_list_head.
To parameterize the bpf_list_head for a certain value type and the
list_node member it will accept in that value type, we use BTF
declaration tags.

The definition of bpf_list_head in a map value will be done as follows:

struct foo {
	struct bpf_list_node node;
	int data;
};

struct map_value {
	struct bpf_list_head head __contains(foo, node);
};

Then, the bpf_list_head only allows adding to the list 'head' using the
bpf_list_node 'node' for the type struct foo.

The 'contains' annotation is a BTF declaration tag composed of four
parts, "contains:name:node" where the name is then used to look up the
type in the map BTF, with its kind hardcoded to BTF_KIND_STRUCT during
the lookup. The node defines name of the member in this type that has
the type struct bpf_list_node, which is actually used for linking into
the linked list. For now, 'kind' part is hardcoded as struct.

This allows building intrusive linked lists in BPF, using container_of
to obtain pointer to entry, while being completely type safe from the
perspective of the verifier. The verifier knows exactly the type of the
nodes, and knows that list helpers return that type at some fixed offset
where the bpf_list_node member used for this list exists. The verifier
also uses this information to disallow adding types that are not
accepted by a certain list.

For now, no elements can be added to such lists. Support for that is
coming in future patches, hence draining and freeing items is done with
a TODO that will be resolved in a future patch.

Note that the bpf_list_head_free function moves the list out to a local
variable under the lock and releases it, doing the actual draining of
the list items outside the lock. While this helps with not holding the
lock for too long pessimizing other concurrent list operations, it is
also necessary for deadlock prevention: unless every function called in
the critical section would be notrace, a fentry/fexit program could
attach and call bpf_map_update_elem again on the map, leading to the
same lock being acquired if the key matches and lead to a deadlock.
While this requires some special effort on part of the BPF programmer to
trigger and is highly unlikely to occur in practice, it is always better
if we can avoid such a condition.

While notrace would prevent this, doing the draining outside the lock
has advantages of its own, hence it is used to also fix the deadlock
related problem.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14 21:52:45 -08:00
Kumar Kartikeya Dwivedi
2d57725257 bpf: Remove BPF_MAP_OFF_ARR_MAX
In f71b2f6417 ("bpf: Refactor map->off_arr handling"), map->off_arr
was refactored to be btf_field_offs. The number of field offsets is
equal to maximum possible fields limited by BTF_FIELDS_MAX. Hence, reuse
BTF_FIELDS_MAX as spin_lock and timer no longer are to be handled
specially for offset sorting, fix the comment, and remove incorrect
WARN_ON as its rec->cnt can never exceed this value. The reason to keep
separate constant was the it was always more 2 more than total kptrs.
This is no longer the case.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14 21:52:45 -08:00
Peter Zijlstra
91dabf33ae sched: Fix race in task_call_func()
There is a very narrow race between schedule() and task_call_func().

  CPU0						CPU1

  __schedule()
    rq_lock();
    prev_state = READ_ONCE(prev->__state);
    if (... && prev_state) {
      deactivate_tasl(rq, prev, ...)
        prev->on_rq = 0;

						task_call_func()
						  raw_spin_lock_irqsave(p->pi_lock);
						  state = READ_ONCE(p->__state);
						  smp_rmb();
						  if (... || p->on_rq) // false!!!
						    rq = __task_rq_lock()

						  ret = func();

    next = pick_next_task();
    rq = context_switch(prev, next)
      prepare_lock_switch()
        spin_release(&__rq_lockp(rq)->dep_map...)

So while the task is on it's way out, it still holds rq->lock for a
little while, and right then task_call_func() comes in and figures it
doesn't need rq->lock anymore (because the task is already dequeued --
but still running there) and then the __set_task_frozen() thing observes
it's holding rq->lock and yells murder.

Avoid this by waiting for p->on_cpu to get cleared, which guarantees
the task is fully finished on the old CPU.

( While arguably the fixes tag is 'wrong' -- none of the previous
  task_call_func() users appears to care for this case. )

Fixes: f5d39b0208 ("freezer,sched: Rewrite core freezer logic")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://lkml.kernel.org/r/Y1kdRNNfUeAU+FNl@hirez.programming.kicks-ass.net
2022-11-14 09:58:32 +01:00
Mathieu Desnoyers
448dca8c88 rseq: Use pr_warn_once() when deprecated/unknown ABI flags are encountered
These commits use WARN_ON_ONCE() and kill the offending processes when
deprecated and unknown flags are encountered:

commit c17a6ff932 ("rseq: Kill process when unknown flags are encountered in ABI structures")
commit 0190e4198e ("rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_* flags")

The WARN_ON_ONCE() triggered by userspace input prevents use of
Syzkaller to fuzz the rseq system call.

Replace this WARN_ON_ONCE() by pr_warn_once() messages which contain
actually useful information.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lkml.kernel.org/r/20221102130635.7379-1-mathieu.desnoyers@efficios.com
2022-11-14 09:58:32 +01:00
Jakub Kicinski
f4c4ca70de Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Andrii Nakryiko says:

====================
bpf-next 2022-11-11

We've added 49 non-merge commits during the last 9 day(s) which contain
a total of 68 files changed, 3592 insertions(+), 1371 deletions(-).

The main changes are:

1) Veristat tool improvements to support custom filtering, sorting, and replay
   of results, from Andrii Nakryiko.

2) BPF verifier precision tracking fixes and improvements,
   from Andrii Nakryiko.

3) Lots of new BPF documentation for various BPF maps, from Dave Tucker,
   Donald Hunter, Maryam Tahhan, Bagas Sanjaya.

4) BTF dedup improvements and libbpf's hashmap interface clean ups, from
   Eduard Zingerman.

5) Fix veth driver panic if XDP program is attached before veth_open, from
   John Fastabend.

6) BPF verifier clean ups and fixes in preparation for follow up features,
   from Kumar Kartikeya Dwivedi.

7) Add access to hwtstamp field from BPF sockops programs,
   from Martin KaFai Lau.

8) Various fixes for BPF selftests and samples, from Artem Savkov,
   Domenico Cerasuolo, Kang Minchul, Rong Tao, Yang Jihong.

9) Fix redirection to tunneling device logic, preventing skb->len == 0, from
   Stanislav Fomichev.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (49 commits)
  selftests/bpf: fix veristat's singular file-or-prog filter
  selftests/bpf: Test skops->skb_hwtstamp
  selftests/bpf: Fix incorrect ASSERT in the tcp_hdr_options test
  bpf: Add hwtstamp field for the sockops prog
  selftests/bpf: Fix xdp_synproxy compilation failure in 32-bit arch
  bpf, docs: Document BPF_MAP_TYPE_ARRAY
  docs/bpf: Document BPF map types QUEUE and STACK
  docs/bpf: Document BPF ARRAY_OF_MAPS and HASH_OF_MAPS
  docs/bpf: Document BPF_MAP_TYPE_CPUMAP map
  docs/bpf: Document BPF_MAP_TYPE_LPM_TRIE map
  libbpf: Hashmap.h update to fix build issues using LLVM14
  bpf: veth driver panics when xdp prog attached before veth_open
  selftests: Fix test group SKIPPED result
  selftests/bpf: Tests for btf_dedup_resolve_fwds
  libbpf: Resolve unambigous forward declarations
  libbpf: Hashmap interface update to allow both long and void* keys/values
  samples/bpf: Fix sockex3 error: Missing BPF prog type
  selftests/bpf: Fix u32 variable compared with less than zero
  Documentation: bpf: Escape underscore in BPF type name prefix
  selftests/bpf: Use consistent build-id type for liburandom_read.so
  ...
====================

Link: https://lore.kernel.org/r/20221111233733.1088228-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11 18:33:04 -08:00
Jakub Kicinski
c1754bf019 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Andrii Nakryiko says:

====================
bpf 2022-11-11

We've added 11 non-merge commits during the last 8 day(s) which contain
a total of 11 files changed, 83 insertions(+), 74 deletions(-).

The main changes are:

1) Fix strncpy_from_kernel_nofault() to prevent out-of-bounds writes,
   from Alban Crequy.

2) Fix for bpf_prog_test_run_skb() to prevent wrong alignment,
   from Baisong Zhong.

3) Switch BPF_DISPATCHER to static_call() instead of ftrace infra, with
   a small build fix on top, from Peter Zijlstra and Nathan Chancellor.

4) Fix memory leak in BPF verifier in some error cases, from Wang Yufen.

5) 32-bit compilation error fixes for BPF selftests, from Pu Lehui and
   Yang Jihong.

6) Ensure even distribution of per-CPU free list elements, from Xu Kuohai.

7) Fix copy_map_value() to track special zeroed out areas properly,
   from Xu Kuohai.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix offset calculation error in __copy_map_value and zero_map_value
  bpf: Initialize same number of free nodes for each pcpu_freelist
  selftests: bpf: Add a test when bpf_probe_read_kernel_str() returns EFAULT
  maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault()
  selftests/bpf: Fix test_progs compilation failure in 32-bit arch
  selftests/bpf: Fix casting error when cross-compiling test_verifier for 32-bit platforms
  bpf: Fix memory leaks in __check_func_call
  bpf: Add explicit cast to 'void *' for __BPF_DISPATCHER_UPDATE()
  bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)
  bpf: Revert ("Fix dispatcher patchable function entry to 5 bytes nop")
  bpf, test_run: Fix alignment problem in bpf_prog_test_run_skb()
====================

Link: https://lore.kernel.org/r/20221111231624.938829-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-11 18:27:40 -08:00
Xu Kuohai
4b45cd81f7 bpf: Initialize same number of free nodes for each pcpu_freelist
pcpu_freelist_populate() initializes nr_elems / num_possible_cpus() + 1
free nodes for some CPUs, and then possibly one CPU with fewer nodes,
followed by remaining cpus with 0 nodes. For example, when nr_elems == 256
and num_possible_cpus() == 32, CPU 0~27 each gets 9 free nodes, CPU 28 gets
4 free nodes, CPU 29~31 get 0 free nodes, while in fact each CPU should get
8 nodes equally.

This patch initializes nr_elems / num_possible_cpus() free nodes for each
CPU firstly, then allocates the remaining free nodes by one for each CPU
until no free nodes left.

Fixes: e19494edab ("bpf: introduce percpu_freelist")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221110122128.105214-1-xukuohai@huawei.com
2022-11-11 12:05:14 -08:00
Maryam Tahhan
161939abc8 docs/bpf: Document BPF_MAP_TYPE_CPUMAP map
Add documentation for BPF_MAP_TYPE_CPUMAP including
kernel version introduced, usage and examples.

Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Maryam Tahhan <mtahhan@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221107165207.2682075-2-mtahhan@redhat.com
2022-11-11 11:32:54 -08:00
Jakub Kicinski
966a9b4903 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/can/pch_can.c
  ae64438be1 ("can: dev: fix skb drop check")
  1dd1b521be ("can: remove obsolete PCH CAN driver")
https://lore.kernel.org/all/20221110102509.1f7d63cc@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-10 17:43:53 -08:00
Linus Torvalds
4bbf3422df Merge tag 'net-6.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, wifi, can and bpf.

  Current release - new code bugs:

   - can: af_can: can_exit(): add missing dev_remove_pack() of
     canxl_packet

  Previous releases - regressions:

   - bpf, sockmap: fix the sk->sk_forward_alloc warning

   - wifi: mac80211: fix general-protection-fault in
     ieee80211_subif_start_xmit()

   - can: af_can: fix NULL pointer dereference in can_rx_register()

   - can: dev: fix skb drop check, avoid o-o-b access

   - nfnetlink: fix potential dead lock in nfnetlink_rcv_msg()

  Previous releases - always broken:

   - bpf: fix wrong reg type conversion in release_reference()

   - gso: fix panic on frag_list with mixed head alloc types

   - wifi: brcmfmac: fix buffer overflow in brcmf_fweh_event_worker()

   - wifi: mac80211: set TWT Information Frame Disabled bit as 1

   - eth: macsec offload related fixes, make sure to clear the keys from
     memory

   - tun: fix memory leaks in the use of napi_get_frags

   - tun: call napi_schedule_prep() to ensure we own a napi

   - tcp: prohibit TCP_REPAIR_OPTIONS if data was already sent

   - ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to
     network

   - tipc: fix a msg->req tlv length check

   - sctp: clear out_curr if all frag chunks of current msg are pruned,
     avoid list corruption

   - mctp: fix an error handling path in mctp_init(), avoid leaks"

* tag 'net-6.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (101 commits)
  eth: sp7021: drop free_netdev() from spl2sw_init_netdev()
  MAINTAINERS: Move Vivien to CREDITS
  net: macvlan: fix memory leaks of macvlan_common_newlink
  ethernet: tundra: free irq when alloc ring failed in tsi108_open()
  net: mv643xx_eth: disable napi when init rxq or txq failed in mv643xx_eth_open()
  ethernet: s2io: disable napi when start nic failed in s2io_card_up()
  net: atlantic: macsec: clear encryption keys from the stack
  net: phy: mscc: macsec: clear encryption keys when freeing a flow
  stmmac: dwmac-loongson: fix missing of_node_put() while module exiting
  stmmac: dwmac-loongson: fix missing pci_disable_device() in loongson_dwmac_probe()
  stmmac: dwmac-loongson: fix missing pci_disable_msi() while module exiting
  cxgb4vf: shut down the adapter when t4vf_update_port_info() failed in cxgb4vf_open()
  mctp: Fix an error handling path in mctp_init()
  stmmac: intel: Update PCH PTP clock rate from 200MHz to 204.8MHz
  net: cxgb3_main: disable napi when bind qsets failed in cxgb_up()
  net: cpsw: disable napi in cpsw_ndo_open()
  iavf: Fix VF driver counting VLAN 0 filters
  ice: Fix spurious interrupt during removal of trusted VF
  net/mlx5e: TC, Fix slab-out-of-bounds in parse_tc_actions
  net/mlx5e: E-Switch, Fix comparing termination table instance
  ...
2022-11-10 17:31:15 -08:00
Wang Yufen
eb86559a69 bpf: Fix memory leaks in __check_func_call
kmemleak reports this issue:

unreferenced object 0xffff88817139d000 (size 2048):
  comm "test_progs", pid 33246, jiffies 4307381979 (age 45851.820s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000045f075f0>] kmalloc_trace+0x27/0xa0
    [<0000000098b7c90a>] __check_func_call+0x316/0x1230
    [<00000000b4c3c403>] check_helper_call+0x172e/0x4700
    [<00000000aa3875b7>] do_check+0x21d8/0x45e0
    [<000000001147357b>] do_check_common+0x767/0xaf0
    [<00000000b5a595b4>] bpf_check+0x43e3/0x5bc0
    [<0000000011e391b1>] bpf_prog_load+0xf26/0x1940
    [<0000000007f765c0>] __sys_bpf+0xd2c/0x3650
    [<00000000839815d6>] __x64_sys_bpf+0x75/0xc0
    [<00000000946ee250>] do_syscall_64+0x3b/0x90
    [<0000000000506b7f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

The root case here is: In function prepare_func_exit(), the callee is
not released in the abnormal scenario after "state->curframe--;". To
fix, move "state->curframe--;" to the very bottom of the function,
right when we free callee and reset frame[] pointer to NULL, as Andrii
suggested.

In addition, function __check_func_call() has a similar problem. In
the abnormal scenario before "state->curframe++;", the callee also
should be released by free_func_state().

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Fixes: fd978bf7fd ("bpf: Add reference tracking to verifier")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1667884291-15666-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-11-08 09:21:35 -08:00
Marco Elver
bb88f96954 perf: Improve missing SIGTRAP checking
To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(),
which fires if pending_sigtrap was already set: returning to user space
without consuming pending_sigtrap, and then having the event fire again
would re-enter the kernel and trigger the WARN.

This, however, seemed to miss the case where some events not associated
with progress in the user space task can fire and the interrupt handler
runs before the IRQ work meant to consume pending_sigtrap (and generate
the SIGTRAP).

syzbot gifted us this stack trace:

 | WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow
 | Modules linked in:
 | CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0
 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
 | RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313
 | <...>
 | Call Trace:
 |  <TASK>
 |  perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729
 |  __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 |  __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749
 |  hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 |  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 |  __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
 |  sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107
 |  asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
 | <...>
 |  </TASK>

In this case, syzbot produced a program with event type
PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer
manages to fire again before the IRQ work got a chance to run, all while
never having returned to user space.

Improve the WARN to check for real progress in user space: approximate
this by storing a 32-bit hash of the current IP into pending_sigtrap,
and if an event fires while pending_sigtrap still matches the previous
IP, we assume no progress (false negatives are possible given we could
return to user space and trigger again on the same IP).

Fixes: ca6c21327c ("perf: Fix missing SIGTRAPs")
Reported-by: syzbot+b8ded3e2e2c6adde4990@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221031093513.3032814-1-elver@google.com
2022-11-08 10:39:27 +01:00
Nathan Chancellor
a679120edf bpf: Add explicit cast to 'void *' for __BPF_DISPATCHER_UPDATE()
When building with clang:

  kernel/bpf/dispatcher.c:126:33: error: pointer type mismatch ('void *' and 'unsigned int (*)(const void *, const struct bpf_insn *, bpf_func_t)' (aka 'unsigned int (*)(const void *, const struct bpf_insn *, unsigned int (*)(const void *, const struct bpf_insn *))')) [-Werror,-Wpointer-type-mismatch]
          __BPF_DISPATCHER_UPDATE(d, new ?: &bpf_dispatcher_nop_func);
                                     ~~~ ^  ~~~~~~~~~~~~~~~~~~~~~~~~
  ./include/linux/bpf.h:1045:54: note: expanded from macro '__BPF_DISPATCHER_UPDATE'
          __static_call_update((_d)->sc_key, (_d)->sc_tramp, (_new))
                                                              ^~~~
  1 error generated.

The warning is pointing out that the type of new ('void *') and
&bpf_dispatcher_nop_func are not compatible, which could have side
effects coming out of a conditional operator due to promotion rules.

Add the explicit cast to 'void *' to make it clear that this is
expected, as __BPF_DISPATCHER_UPDATE() expands to a call to
__static_call_update(), which expects a 'void *' as its final argument.

Fixes: c86df29d11 ("bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)")
Link: https://github.com/ClangBuiltLinux/linux/issues/1755
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221107170711.42409-1-nathan@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-11-07 16:07:35 -08:00
Linus Torvalds
727ea09e99 Merge tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:

 - Add Cooper Lake's stepping to the PEBS guest/host events isolation
   fixed microcode revisions checking quirk

 - Update Icelake and Sapphire Rapids events constraints

 - Use the standard energy unit for Sapphire Rapids in RAPL

 - Fix the hw_breakpoint test to fail more graciously on !SMP configs

* tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[]
  perf/x86/intel: Fix pebs event constraints for SPR
  perf/x86/intel: Fix pebs event constraints for ICL
  perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain
  perf/hw_breakpoint: test: Skip the test if dependencies unmet
2022-11-06 12:41:32 -08:00
Peter Zijlstra
c86df29d11 bpf: Convert BPF_DISPATCHER to use static_call() (not ftrace)
The dispatcher function is currently abusing the ftrace __fentry__
call location for its own purposes -- this obviously gives trouble
when the dispatcher and ftrace are both in use.

A previous solution tried using __attribute__((patchable_function_entry()))
which works, except it is GCC-8+ only, breaking the build on the
earlier still supported compilers. Instead use static_call() -- which
has its own annotations and does not conflict with ftrace -- to
rewrite the dispatch function.

By using: return static_call()(ctx, insni, bpf_func) you get a perfect
forwarding tail call as function body (iow a single jmp instruction).
By having the default static_call() target be bpf_dispatcher_nop_func()
it retains the default behaviour (an indirect call to the argument
function). Only once a dispatcher program is attached is the target
rewritten to directly call the JIT'ed image.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lkml.kernel.org/r/Y1/oBlK0yFk5c/Im@hirez.programming.kicks-ass.net
Link: https://lore.kernel.org/bpf/20221103120647.796772565@infradead.org
2022-11-04 23:13:57 +01:00
Peter Zijlstra
18acb7fac2 bpf: Revert ("Fix dispatcher patchable function entry to 5 bytes nop")
Because __attribute__((patchable_function_entry)) is only available
since GCC-8 this solution fails to build on the minimum required GCC
version.

Undo these changes so we might try again -- without cluttering up the
patches with too many changes.

This is an almost complete revert of:

  dbe69b2998 ("bpf: Fix dispatcher patchable function entry to 5 bytes nop")
  ceea991a01 ("bpf: Move bpf_dispatcher function out of ftrace locations")

(notably the arch/x86/Kconfig hunk is kept).

Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lkml.kernel.org/r/439d8dc735bb4858875377df67f1b29a@AcuMS.aculab.com
Link: https://lore.kernel.org/bpf/20221103120647.728830733@infradead.org
2022-11-04 23:13:08 +01:00
Andrii Nakryiko
7a830b53c1 bpf: aggressively forget precise markings during state checkpointing
Exploit the property of about-to-be-checkpointed state to be able to
forget all precise markings up to that point even more aggressively. We
now clear all potentially inherited precise markings right before
checkpointing and branching off into child state. If any of children
states require precise knowledge of any SCALAR register, those will be
propagated backwards later on before this state is finalized, preserving
correctness.

There is a single selftests BPF program change, but tremendous one: 25x
reduction in number of verified instructions and states in
trace_virtqueue_add_sgs.

Cilium results are more modest, but happen across wider range of programs.

SELFTESTS RESULTS
=================

$ ./veristat -C -e file,prog,insns,states ~/imprecise-early-results.csv ~/imprecise-aggressive-results.csv | grep -v '+0'
File                 Program                  Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
-------------------  -----------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
loop6.bpf.linked1.o  trace_virtqueue_add_sgs           398057            15114   -382943 (-96.20%)              8717               336      -8381 (-96.15%)
-------------------  -----------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

CILIUM RESULTS
==============

$ ./veristat -C -e file,prog,insns,states ~/imprecise-early-results-cilium.csv ~/imprecise-aggressive-results-cilium.csv | grep -v '+0'
File           Program                           Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
-------------  --------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
bpf_host.o     tail_handle_nat_fwd_ipv4                    23426            23221       -205 (-0.88%)              1537              1515         -22 (-1.43%)
bpf_host.o     tail_handle_nat_fwd_ipv6                    13009            12904       -105 (-0.81%)               719               708         -11 (-1.53%)
bpf_host.o     tail_nodeport_nat_ingress_ipv6               5261             5196        -65 (-1.24%)               247               243          -4 (-1.62%)
bpf_host.o     tail_nodeport_nat_ipv6_egress                3446             3406        -40 (-1.16%)               203               198          -5 (-2.46%)
bpf_lxc.o      tail_handle_nat_fwd_ipv4                    23426            23221       -205 (-0.88%)              1537              1515         -22 (-1.43%)
bpf_lxc.o      tail_handle_nat_fwd_ipv6                    13009            12904       -105 (-0.81%)               719               708         -11 (-1.53%)
bpf_lxc.o      tail_ipv4_ct_egress                          5074             4897       -177 (-3.49%)               255               248          -7 (-2.75%)
bpf_lxc.o      tail_ipv4_ct_ingress                         5100             4923       -177 (-3.47%)               255               248          -7 (-2.75%)
bpf_lxc.o      tail_ipv4_ct_ingress_policy_only             5100             4923       -177 (-3.47%)               255               248          -7 (-2.75%)
bpf_lxc.o      tail_ipv6_ct_egress                          4558             4536        -22 (-0.48%)               188               187          -1 (-0.53%)
bpf_lxc.o      tail_ipv6_ct_ingress                         4578             4556        -22 (-0.48%)               188               187          -1 (-0.53%)
bpf_lxc.o      tail_ipv6_ct_ingress_policy_only             4578             4556        -22 (-0.48%)               188               187          -1 (-0.53%)
bpf_lxc.o      tail_nodeport_nat_ingress_ipv6               5261             5196        -65 (-1.24%)               247               243          -4 (-1.62%)
bpf_overlay.o  tail_nodeport_nat_ingress_ipv6               5261             5196        -65 (-1.24%)               247               243          -4 (-1.62%)
bpf_overlay.o  tail_nodeport_nat_ipv6_egress                3482             3442        -40 (-1.15%)               204               201          -3 (-1.47%)
bpf_xdp.o      tail_nodeport_nat_egress_ipv4               17200            15619      -1581 (-9.19%)              1111              1010        -101 (-9.09%)
-------------  --------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-04 11:51:45 -07:00
Andrii Nakryiko
f63181b6ae bpf: stop setting precise in current state
Setting reg->precise to true in current state is not necessary from
correctness standpoint, but it does pessimise the whole precision (or
rather "imprecision", because that's what we want to keep as much as
possible) tracking. Why is somewhat subtle and my best attempt to
explain this is recorded in an extensive comment for __mark_chain_precise()
function. Some more careful thinking and code reading is probably required
still to grok this completely, unfortunately. Whiteboarding and a bunch
of extra handwaiving in person would be even more helpful, but is deemed
impractical in Git commit.

Next patch pushes this imprecision property even further, building on top of
the insights described in this patch.

End results are pretty nice, we get reduction in number of total instructions
and states verified due to a better states reuse, as some of the states are now
more generic and permissive due to less unnecessary precise=true requirements.

SELFTESTS RESULTS
=================

$ ./veristat -C -e file,prog,insns,states ~/subprog-precise-results.csv ~/imprecise-early-results.csv | grep -v '+0'
File                                     Program                 Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
---------------------------------------  ----------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
bpf_iter_ksym.bpf.linked1.o              dump_ksym                           347              285       -62 (-17.87%)                20                19          -1 (-5.00%)
pyperf600_bpf_loop.bpf.linked1.o         on_event                           3678             3736        +58 (+1.58%)               276               285          +9 (+3.26%)
setget_sockopt.bpf.linked1.o             skops_sockopt                      4038             3947        -91 (-2.25%)               347               343          -4 (-1.15%)
test_l4lb.bpf.linked1.o                  balancer_ingress                   4559             2611     -1948 (-42.73%)               118               105        -13 (-11.02%)
test_l4lb_noinline.bpf.linked1.o         balancer_ingress                   6279             6268        -11 (-0.18%)               237               236          -1 (-0.42%)
test_misc_tcp_hdr_options.bpf.linked1.o  misc_estab                         1307             1303         -4 (-0.31%)               100                99          -1 (-1.00%)
test_sk_lookup.bpf.linked1.o             ctx_narrow_access                   456              447         -9 (-1.97%)                39                38          -1 (-2.56%)
test_sysctl_loop1.bpf.linked1.o          sysctl_tcp_mem                     1389             1384         -5 (-0.36%)                26                25          -1 (-3.85%)
test_tc_dtime.bpf.linked1.o              egress_fwdns_prio101                518              485        -33 (-6.37%)                51                46          -5 (-9.80%)
test_tc_dtime.bpf.linked1.o              egress_host                         519              468        -51 (-9.83%)                50                44         -6 (-12.00%)
test_tc_dtime.bpf.linked1.o              ingress_fwdns_prio101               842             1000      +158 (+18.76%)                73                88        +15 (+20.55%)
xdp_synproxy_kern.bpf.linked1.o          syncookie_tc                     405757           373173     -32584 (-8.03%)             25735             22882      -2853 (-11.09%)
xdp_synproxy_kern.bpf.linked1.o          syncookie_xdp                    479055           371590   -107465 (-22.43%)             29145             22207      -6938 (-23.81%)
---------------------------------------  ----------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

Slight regression in test_tc_dtime.bpf.linked1.o/ingress_fwdns_prio101
is left for a follow up, there might be some more precision-related bugs
in existing BPF verifier logic.

CILIUM RESULTS
==============

$ ./veristat -C -e file,prog,insns,states ~/subprog-precise-results-cilium.csv ~/imprecise-early-results-cilium.csv | grep -v '+0'
File           Program                         Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
-------------  ------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
bpf_host.o     cil_from_host                               762              556      -206 (-27.03%)                43                37         -6 (-13.95%)
bpf_host.o     tail_handle_nat_fwd_ipv4                  23541            23426       -115 (-0.49%)              1538              1537          -1 (-0.07%)
bpf_host.o     tail_nodeport_nat_egress_ipv4             33592            33566        -26 (-0.08%)              2163              2161          -2 (-0.09%)
bpf_lxc.o      tail_handle_nat_fwd_ipv4                  23541            23426       -115 (-0.49%)              1538              1537          -1 (-0.07%)
bpf_overlay.o  tail_nodeport_nat_egress_ipv4             33581            33543        -38 (-0.11%)              2160              2157          -3 (-0.14%)
bpf_xdp.o      tail_handle_nat_fwd_ipv4                  21659            20920       -739 (-3.41%)              1440              1376         -64 (-4.44%)
bpf_xdp.o      tail_handle_nat_fwd_ipv6                  17084            17039        -45 (-0.26%)               907               905          -2 (-0.22%)
bpf_xdp.o      tail_lb_ipv4                              73442            73430        -12 (-0.02%)              4370              4369          -1 (-0.02%)
bpf_xdp.o      tail_lb_ipv6                             152114           151895       -219 (-0.14%)              6493              6479         -14 (-0.22%)
bpf_xdp.o      tail_nodeport_nat_egress_ipv4             17377            17200       -177 (-1.02%)              1125              1111         -14 (-1.24%)
bpf_xdp.o      tail_nodeport_nat_ingress_ipv6             6405             6397         -8 (-0.12%)               309               308          -1 (-0.32%)
bpf_xdp.o      tail_rev_nodeport_lb4                      7126             6934       -192 (-2.69%)               414               402         -12 (-2.90%)
bpf_xdp.o      tail_rev_nodeport_lb6                     18059            17905       -154 (-0.85%)              1105              1096          -9 (-0.81%)
-------------  ------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-04 11:51:45 -07:00
Andrii Nakryiko
be2ef81615 bpf: allow precision tracking for programs with subprogs
Stop forcing precise=true for SCALAR registers when BPF program has any
subprograms. Current restriction means that any BPF program, as soon as
it uses subprograms, will end up not getting any of the precision
tracking benefits in reduction of number of verified states.

This patch keeps the fallback mark_all_scalars_precise() behavior if
precise marking has to cross function frames. E.g., if subprogram
requires R1 (first input arg) to be marked precise, ideally we'd need to
backtrack to the parent function and keep marking R1 and its
dependencies as precise. But right now we give up and force all the
SCALARs in any of the current and parent states to be forced to
precise=true. We can lift that restriction in the future.

But this patch fixes two issues identified when trying to enable
precision tracking for subprogs.

First, prevent "escaping" from top-most state in a global subprog. While
with entry-level BPF program we never end up requesting precision for
R1-R5 registers, because R2-R5 are not initialized (and so not readable
in correct BPF program), and R1 is PTR_TO_CTX, not SCALAR, and so is
implicitly precise. With global subprogs, though, it's different, as
global subprog a) can have up to 5 SCALAR input arguments, which might
get marked as precise=true and b) it is validated in isolation from its
main entry BPF program. b) means that we can end up exhausting parent
state chain and still not mark all registers in reg_mask as precise,
which would lead to verifier bug warning.

To handle that, we need to consider two cases. First, if the very first
state is not immediately "checkpointed" (i.e., stored in state lookup
hashtable), it will get correct first_insn_idx and last_insn_idx
instruction set during state checkpointing. As such, this case is
already handled and __mark_chain_precision() already handles that by
just doing nothing when we reach to the very first parent state.
st->parent will be NULL and we'll just stop. Perhaps some extra check
for reg_mask and stack_mask is due here, but this patch doesn't address
that issue.

More problematic second case is when global function's initial state is
immediately checkpointed before we manage to process the very first
instruction. This is happening because when there is a call to global
subprog from the main program the very first subprog's instruction is
marked as pruning point, so before we manage to process first
instruction we have to check and checkpoint state. This patch adds
a special handling for such "empty" state, which is identified by having
st->last_insn_idx set to -1. In such case, we check that we are indeed
validating global subprog, and with some sanity checking we mark input
args as precise if requested.

Note that we also initialize state->first_insn_idx with correct start
insn_idx offset. For main program zero is correct value, but for any
subprog it's quite confusing to not have first_insn_idx set. This
doesn't have any functional impact, but helps with debugging and state
printing. We also explicitly initialize state->last_insns_idx instead of
relying on is_state_visited() to do this with env->prev_insns_idx, which
will be -1 on the very first instruction. This concludes necessary
changes to handle specifically global subprog's precision tracking.

Second identified problem was missed handling of BPF helper functions
that call into subprogs (e.g., bpf_loop and few others). From precision
tracking and backtracking logic's standpoint those are effectively calls
into subprogs and should be called as BPF_PSEUDO_CALL calls.

This patch takes the least intrusive way and just checks against a short
list of current BPF helpers that do call subprogs, encapsulated in
is_callback_calling_function() function. But to prevent accidentally
forgetting to add new BPF helpers to this "list", we also do a sanity
check in __check_func_call, which has to be called for each such special
BPF helper, to validate that BPF helper is indeed recognized as
callback-calling one. This should catch any missed checks in the future.
Adding some special flags to be added in function proto definitions
seemed like an overkill in this case.

With the above changes, it's possible to remove forceful setting of
reg->precise to true in __mark_reg_unknown, which turns on precision
tracking both inside subprogs and entry progs that have subprogs. No
warnings or errors were detected across all the selftests, but also when
validating with veristat against internal Meta BPF objects and Cilium
objects. Further, in some BPF programs there are noticeable reduction in
number of states and instructions validated due to more effective
precision tracking, especially benefiting syncookie test.

$ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/subprog-precise-results.csv  | grep -v '+0'
File                                      Program                     Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
----------------------------------------  --------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
pyperf600_bpf_loop.bpf.linked1.o          on_event                               3966             3678       -288 (-7.26%)               306               276         -30 (-9.80%)
pyperf_global.bpf.linked1.o               on_event                               7563             7530        -33 (-0.44%)               520               517          -3 (-0.58%)
pyperf_subprogs.bpf.linked1.o             on_event                              36358            36934       +576 (+1.58%)              2499              2531         +32 (+1.28%)
setget_sockopt.bpf.linked1.o              skops_sockopt                          3965             4038        +73 (+1.84%)               343               347          +4 (+1.17%)
test_cls_redirect_subprogs.bpf.linked1.o  cls_redirect                          64965            64901        -64 (-0.10%)              4619              4612          -7 (-0.15%)
test_misc_tcp_hdr_options.bpf.linked1.o   misc_estab                             1491             1307      -184 (-12.34%)               110               100         -10 (-9.09%)
test_pkt_access.bpf.linked1.o             test_pkt_access                         354              349         -5 (-1.41%)                25                24          -1 (-4.00%)
test_sock_fields.bpf.linked1.o            egress_read_sock_fields                 435              375       -60 (-13.79%)                22                20          -2 (-9.09%)
test_sysctl_loop2.bpf.linked1.o           sysctl_tcp_mem                         1508             1501         -7 (-0.46%)                29                28          -1 (-3.45%)
test_tc_dtime.bpf.linked1.o               egress_fwdns_prio100                    468              435        -33 (-7.05%)                45                41          -4 (-8.89%)
test_tc_dtime.bpf.linked1.o               ingress_fwdns_prio100                   398              408        +10 (+2.51%)                42                39          -3 (-7.14%)
test_tc_dtime.bpf.linked1.o               ingress_fwdns_prio101                  1096              842      -254 (-23.18%)                97                73        -24 (-24.74%)
test_tcp_hdr_options.bpf.linked1.o        estab                                  2758             2408      -350 (-12.69%)               208               181        -27 (-12.98%)
test_urandom_usdt.bpf.linked1.o           urand_read_with_sema                    466              448        -18 (-3.86%)                31                28          -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o           urand_read_without_sema                 466              448        -18 (-3.86%)                31                28          -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o           urandlib_read_with_sema                 466              448        -18 (-3.86%)                31                28          -3 (-9.68%)
test_urandom_usdt.bpf.linked1.o           urandlib_read_without_sema              466              448        -18 (-3.86%)                31                28          -3 (-9.68%)
test_xdp_noinline.bpf.linked1.o           balancer_ingress_v6                    4302             4294         -8 (-0.19%)               257               256          -1 (-0.39%)
xdp_synproxy_kern.bpf.linked1.o           syncookie_tc                         583722           405757   -177965 (-30.49%)             35846             25735     -10111 (-28.21%)
xdp_synproxy_kern.bpf.linked1.o           syncookie_xdp                        609123           479055   -130068 (-21.35%)             35452             29145      -6307 (-17.79%)
----------------------------------------  --------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-04 11:51:45 -07:00
Andrii Nakryiko
529409ea92 bpf: propagate precision across all frames, not just the last one
When equivalent completed state is found and it has additional precision
restrictions, BPF verifier propagates precision to
currently-being-verified state chain (i.e., including parent states) so
that if some of the states in the chain are not yet completed, necessary
precision restrictions are enforced.

Unfortunately, right now this happens only for the last frame (deepest
active subprogram's frame), not all the frames. This can lead to
incorrect matching of states due to missing precision marker. Currently
this doesn't seem possible as BPF verifier forces everything to precise
when validated BPF program has any subprograms. But with the next patch
lifting this restriction, this becomes problematic.

In fact, without this fix, we'll start getting failure in one of the
existing test_verifier test cases:

  #906/p precise: cross frame pruning FAIL
  Unexpected success to load!
  verification time 48 usec
  stack depth 0+0
  processed 26 insns (limit 1000000) max_states_per_insn 3 total_states 17 peak_states 17 mark_read 8

This patch adds precision propagation across all frames.

Fixes: a3ce685dd0 ("bpf: fix precision tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-04 11:51:45 -07:00
Andrii Nakryiko
a3b666bfa9 bpf: propagate precision in ALU/ALU64 operations
When processing ALU/ALU64 operations (apart from BPF_MOV, which is
handled correctly already; and BPF_NEG and BPF_END are special and don't
have source register), if destination register is already marked
precise, this causes problem with potentially missing precision tracking
for the source register. E.g., when we have r1 >>= r5 and r1 is marked
precise, but r5 isn't, this will lead to r5 staying as imprecise. This
is due to the precision backtracking logic stopping early when it sees
r1 is already marked precise. If r1 wasn't precise, we'd keep
backtracking and would add r5 to the set of registers that need to be
marked precise. So there is a discrepancy here which can lead to invalid
and incompatible states matched due to lack of precision marking on r5.
If r1 wasn't precise, precision backtracking would correctly mark both
r1 and r5 as precise.

This is simple to fix, though. During the forward instruction simulation
pass, for arithmetic operations of `scalar <op>= scalar` form (where
<op> is ALU or ALU64 operations), if destination register is already
precise, mark source register as precise. This applies only when both
involved registers are SCALARs. `ptr += scalar` and `scalar += ptr`
cases are already handled correctly.

This does have (negative) effect on some selftest programs and few
Cilium programs.  ~/baseline-tmp-results.csv are veristat results with
this patch, while ~/baseline-results.csv is without it. See post
scriptum for instructions on how to make Cilium programs testable with
veristat. Correctness has a price.

$ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/baseline-tmp-results.csv | grep -v '+0'
File                     Program               Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
-----------------------  --------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
bpf_cubic.bpf.linked1.o  bpf_cubic_cong_avoid              997             1700      +703 (+70.51%)                62                90        +28 (+45.16%)
test_l4lb.bpf.linked1.o  balancer_ingress                 4559             5469      +910 (+19.96%)               118               126          +8 (+6.78%)
-----------------------  --------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

$ ./veristat -C -e file,prog,verdict,insns,states ~/baseline-results-cilium.csv ~/baseline-tmp-results-cilium.csv | grep -v '+0'
File           Program                         Total insns (A)  Total insns (B)  Total insns (DIFF)  Total states (A)  Total states (B)  Total states (DIFF)
-------------  ------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------
bpf_host.o     tail_nodeport_nat_ingress_ipv6             4448             5261      +813 (+18.28%)               234               247         +13 (+5.56%)
bpf_host.o     tail_nodeport_nat_ipv6_egress              3396             3446        +50 (+1.47%)               201               203          +2 (+1.00%)
bpf_lxc.o      tail_nodeport_nat_ingress_ipv6             4448             5261      +813 (+18.28%)               234               247         +13 (+5.56%)
bpf_overlay.o  tail_nodeport_nat_ingress_ipv6             4448             5261      +813 (+18.28%)               234               247         +13 (+5.56%)
bpf_xdp.o      tail_lb_ipv4                              71736            73442      +1706 (+2.38%)              4295              4370         +75 (+1.75%)
-------------  ------------------------------  ---------------  ---------------  ------------------  ----------------  ----------------  -------------------

P.S. To make Cilium ([0]) programs libbpf-compatible and thus
veristat-loadable, apply changes from topmost commit in [1], which does
minimal changes to Cilium source code, mostly around SEC() annotations
and BPF map definitions.

  [0] https://github.com/cilium/cilium/
  [1] https://github.com/anakryiko/cilium/commits/libbpf-friendliness

Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-04 11:51:45 -07:00
Kumar Kartikeya Dwivedi
f71b2f6417 bpf: Refactor map->off_arr handling
Refactor map->off_arr handling into generic functions that can work on
their own without hardcoding map specific code. The btf_fields_offs
structure is now returned from btf_parse_field_offs, which can be reused
later for types in program BTF.

All functions like copy_map_value, zero_map_value call generic
underlying functions so that they can also be reused later for copying
to values allocated in programs which encode specific fields.

Later, some helper functions will also require access to this
btf_field_offs structure to be able to skip over special fields at
runtime.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-03 23:09:40 -07:00
Kumar Kartikeya Dwivedi
db55911782 bpf: Consolidate spin_lock, timer management into btf_record
Now that kptr_off_tab has been refactored into btf_record, and can hold
more than one specific field type, accomodate bpf_spin_lock and
bpf_timer as well.

While they don't require any more metadata than offset, having all
special fields in one place allows us to share the same code for
allocated user defined types and handle both map values and these
allocated objects in a similar fashion.

As an optimization, we still keep spin_lock_off and timer_off offsets in
the btf_record structure, just to avoid having to find the btf_field
struct each time their offset is needed. This is mostly needed to
manipulate such objects in a map value at runtime. It's ok to hardcode
just one offset as more than one field is disallowed.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-03 22:19:40 -07:00
Kumar Kartikeya Dwivedi
aa3496accc bpf: Refactor kptr_off_tab into btf_record
To prepare the BPF verifier to handle special fields in both map values
and program allocated types coming from program BTF, we need to refactor
the kptr_off_tab handling code into something more generic and reusable
across both cases to avoid code duplication.

Later patches also require passing this data to helpers at runtime, so
that they can work on user defined types, initialize them, destruct
them, etc.

The main observation is that both map values and such allocated types
point to a type in program BTF, hence they can be handled similarly. We
can prepare a field metadata table for both cases and store them in
struct bpf_map or struct btf depending on the use case.

Hence, refactor the code into generic btf_record and btf_field member
structs. The btf_record represents the fields of a specific btf_type in
user BTF. The cnt indicates the number of special fields we successfully
recognized, and field_mask is a bitmask of fields that were found, to
enable quick determination of availability of a certain field.

Subsequently, refactor the rest of the code to work with these generic
types, remove assumptions about kptr and kptr_off_tab, rename variables
to more meaningful names, etc.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-03 21:44:53 -07:00
Jakub Kicinski
f2c24be55b Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
bpf 2022-11-04

We've added 8 non-merge commits during the last 3 day(s) which contain
a total of 10 files changed, 113 insertions(+), 16 deletions(-).

The main changes are:

1) Fix memory leak upon allocation failure in BPF verifier's stack state
   tracking, from Kees Cook.

2) Fix address leakage when BPF progs release reference to an object,
   from Youlin Li.

3) Fix BPF CI breakage from buggy in.h uapi header dependency,
   from Andrii Nakryiko.

4) Fix bpftool pin sub-command's argument parsing, from Pu Lehui.

5) Fix BPF sockmap lockdep warning by cancelling psock work outside
   of socket lock, from Cong Wang.

6) Follow-up for BPF sockmap to fix sk_forward_alloc accounting,
   from Wang Yufen.

bpf-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Add verifier test for release_reference()
  bpf: Fix wrong reg type conversion in release_reference()
  bpf, sock_map: Move cancel_work_sync() out of sock lock
  tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CI
  net/ipv4: Fix linux/in.h header dependencies
  bpftool: Fix NULL pointer dereference when pin {PROG, MAP, LINK} without FILE
  bpf, sockmap: Fix the sk->sk_forward_alloc warning of sk_stream_kill_queues
  bpf, verifier: Fix memory leak in array reallocation for stack state
====================

Link: https://lore.kernel.org/r/20221104000445.30761-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-03 19:51:02 -07:00
Kumar Kartikeya Dwivedi
a28ace782e bpf: Drop reg_type_may_be_refcounted_or_null
It is not scalable to maintain a list of types that can have non-zero
ref_obj_id. It is never set for scalars anyway, so just remove the
conditional on register types and print it whenever it is non-zero.

Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-03 19:31:18 -07:00
Kumar Kartikeya Dwivedi
f5e477a861 bpf: Fix slot type check in check_stack_write_var_off
For the case where allow_ptr_leaks is false, code is checking whether
slot type is STACK_INVALID and STACK_SPILL and rejecting other cases.
This is a consequence of incorrectly checking for register type instead
of the slot type (NOT_INIT and SCALAR_VALUE respectively). Fix the
check.

Fixes: 01f810ace9 ("bpf: Allow variable-offset stack access")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-03 19:31:18 -07:00