diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-02-07 13:15:31 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-02-14 10:32:04 +0100 |
| commit | 72e213a7ccf9dc78a85eecee8dc8170762ed876c (patch) | |
| tree | ed7ad0067e7b4fd3209b274dac4fc592d0bc171d /kernel/trace/bpf_trace.c | |
| parent | 92d2da37fdef65f9aeeb54c991df0cec524934ad (diff) | |
x86/ibt: Clean up is_endbr()
Pretty much every caller of is_endbr() actually wants to test something at an
address and ends up doing get_kernel_nofault(). Fold the lot into a more
convenient helper.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250207122546.181367417@infradead.org
Diffstat (limited to 'kernel/trace/bpf_trace.c')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 21 |
1 files changed, 4 insertions, 17 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index adc947587eb8..997fb2a47c92 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1038,27 +1038,14 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { .arg1_type = ARG_PTR_TO_CTX, }; -#ifdef CONFIG_X86_KERNEL_IBT -static unsigned long get_entry_ip(unsigned long fentry_ip) +static inline unsigned long get_entry_ip(unsigned long fentry_ip) { - u32 instr; - - /* We want to be extra safe in case entry ip is on the page edge, - * but otherwise we need to avoid get_kernel_nofault()'s overhead. - */ - if ((fentry_ip & ~PAGE_MASK) < ENDBR_INSN_SIZE) { - if (get_kernel_nofault(instr, (u32 *)(fentry_ip - ENDBR_INSN_SIZE))) - return fentry_ip; - } else { - instr = *(u32 *)(fentry_ip - ENDBR_INSN_SIZE); - } - if (is_endbr(instr)) +#ifdef CONFIG_X86_KERNEL_IBT + if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE))) fentry_ip -= ENDBR_INSN_SIZE; +#endif return fentry_ip; } -#else -#define get_entry_ip(fentry_ip) fentry_ip -#endif BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) { |