diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2018-01-12 18:54:04 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2018-01-13 02:33:37 +0100 |
| commit | b4da3340eae2c3932144be3e81ccfd4e424d87b7 (patch) | |
| tree | 0a8d2bfcd4dc6a32524dc2b83d2c9169f9bf124a /arch | |
| parent | bpf: simplify xdp_convert_ctx_access for xdp_rxq_info (diff) | |
| download | linux-b4da3340eae2c3932144be3e81ccfd4e424d87b7.tar.xz linux-b4da3340eae2c3932144be3e81ccfd4e424d87b7.zip | |
tracing/kprobe: bpf: Check error injectable event is on function entry
Check whether error injectable event is on function entry or not.
Currently it checks the event is ftrace-based kprobes or not,
but that is wrong. It should check if the event is on the entry
of target function. Since error injection will override a function
to just return with modified return value, that operation must
be done before the target function starts making stackframe.
As a side effect, bpf error injection is no need to depend on
function-tracer. It can work with sw-breakpoint based kprobe
events too.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/kprobes.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/core.c | 14 | ||||
| -rw-r--r-- | arch/x86/kernel/kprobes/ftrace.c | 14 |
3 files changed, 15 insertions, 17 deletions
diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index 36abb23a7a35..367d99cff426 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -67,9 +67,7 @@ extern const int kretprobe_blacklist_size; void arch_remove_kprobe(struct kprobe *p); asmlinkage void kretprobe_trampoline(void); -#ifdef CONFIG_KPROBES_ON_FTRACE -extern void arch_ftrace_kprobe_override_function(struct pt_regs *regs); -#endif +extern void arch_kprobe_override_function(struct pt_regs *regs); /* Architecture specific copy of original instruction*/ struct arch_specific_insn { diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index bd36f3c33cd0..b02a377d5905 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1183,3 +1183,17 @@ int arch_trampoline_kprobe(struct kprobe *p) { return 0; } + +asmlinkage void override_func(void); +asm( + ".type override_func, @function\n" + "override_func:\n" + " ret\n" + ".size override_func, .-override_func\n" +); + +void arch_kprobe_override_function(struct pt_regs *regs) +{ + regs->ip = (unsigned long)&override_func; +} +NOKPROBE_SYMBOL(arch_kprobe_override_function); diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c index 1ea748d682fd..8dc0161cec8f 100644 --- a/arch/x86/kernel/kprobes/ftrace.c +++ b/arch/x86/kernel/kprobes/ftrace.c @@ -97,17 +97,3 @@ int arch_prepare_kprobe_ftrace(struct kprobe *p) p->ainsn.boostable = false; return 0; } - -asmlinkage void override_func(void); -asm( - ".type override_func, @function\n" - "override_func:\n" - " ret\n" - ".size override_func, .-override_func\n" -); - -void arch_ftrace_kprobe_override_function(struct pt_regs *regs) -{ - regs->ip = (unsigned long)&override_func; -} -NOKPROBE_SYMBOL(arch_ftrace_kprobe_override_function); |