diff options
| author | Peter Zijlstra | 2022-09-08 12:04:50 +0200 |
|---|---|---|
| committer | Peter Zijlstra | 2022-09-15 16:13:53 +0200 |
| commit | 8c03af3e090e9d57d90f482d344563dd4bae1e66 (patch) | |
| tree | 8d5a69ee1085ce310672ea551f78baa74ea25c66 /arch/x86/net | |
| parent | bc12b70f7d216b36bd87701349374a13e486f8eb (diff) | |
x86,retpoline: Be sure to emit INT3 after JMP *%\reg
Both AMD and Intel recommend using INT3 after an indirect JMP. Make sure
to emit one when rewriting the retpoline JMP irrespective of compiler
SLS options or even CONFIG_SLS.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Link: https://lkml.kernel.org/r/Yxm+QkFPOhrVSH6q@hirez.programming.kicks-ass.net
Diffstat (limited to 'arch/x86/net')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index c1f6c1c51d99..4922517ddb0d 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -419,7 +419,9 @@ static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip) OPTIMIZER_HIDE_VAR(reg); emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip); } else { - EMIT2(0xFF, 0xE0 + reg); + EMIT2(0xFF, 0xE0 + reg); /* jmp *%\reg */ + if (IS_ENABLED(CONFIG_RETPOLINE) || IS_ENABLED(CONFIG_SLS)) + EMIT1(0xCC); /* int3 */ } *pprog = prog; |