From 52d29b4783268df881b85e76f90da74fbeaa59eb Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Tue, 2 Feb 2021 23:06:36 -0800 Subject: [PATCH] bpf: Unbreak BPF_PROG_TYPE_KPROBE when kprobe is called via do_int3 [ Upstream commit 548f1191d86ccb9bde2a5305988877b7584c01eb ] The commit 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()") converted do_int3 handler to be "NMI-like". That made old if (in_nmi()) check abort execution of bpf programs attached to kprobe when kprobe is firing via int3 (For example when kprobe is placed in the middle of the function). Remove the check to restore user visible behavior. Fixes: 0d00449c7a28 ("x86: Replace ist_enter() with nmi_enter()") Reported-by: Nikolay Borisov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Tested-by: Nikolay Borisov Reviewed-by: Masami Hiramatsu Link: https://lore.kernel.org/bpf/20210203070636.70926-1-alexei.starovoitov@gmail.com Signed-off-by: Sasha Levin --- kernel/trace/bpf_trace.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 0dde84b..fcbfc95 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -93,9 +93,6 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) { unsigned int ret; - if (in_nmi()) /* not supported yet */ - return 1; - cant_sleep(); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { -- 2.7.4