4.19-stable review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu mhiramat@kernel.org
commit 874bfc6e5422d2421f7e4d5ea318d30e91679dfe upstream.
Since commit 4378a7d4be30 ("arm64: implement syscall wrappers") introduced "__arm64_" prefix to all syscall wrapper symbols in sys_call_table, syscall tracer can not find corresponding metadata from syscall name. In the result, we have no syscall ftrace events on arm64 kernel, and some bpf testcases are failed on arm64.
To fix this issue, this introduces custom arch_syscall_match_sym_name() which skips first 8 bytes when comparing the syscall and symbol names.
Fixes: 4378a7d4be30 ("arm64: implement syscall wrappers") Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Acked-by: Will Deacon will.deacon@arm.com Tested-by: Naresh Kamboju naresh.kamboju@linaro.org Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/include/asm/ftrace.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -56,6 +56,19 @@ static inline bool arch_trace_is_compat_ { return is_compat_task(); } + +#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME + +static inline bool arch_syscall_match_sym_name(const char *sym, + const char *name) +{ + /* + * Since all syscall functions have __arm64_ prefix, we must skip it. + * However, as we described above, we decided to ignore compat + * syscalls, so we don't care about __arm64_compat_ prefix here. + */ + return !strcmp(sym + 8, name); +} #endif /* ifndef __ASSEMBLY__ */
#endif /* __ASM_FTRACE_H */