From c285b525903afb7357ad40f65b75cf8bde48881c Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Tue, 2 Feb 2021 23:06:36 -0800 Subject: [PATCH] UPSTREAM: 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 Change-Id: I29ee95686ea9a51b2b59f8b06462510253036360 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 Signed-off-by: Tashfin Shakeer Rhythm --- 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 765adbb5cd1d..892e8ccc2dc5 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -89,9 +89,6 @@ 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)) {