[PATCH 1/2] powerpc/trace elfv1: Update syscall name matching logic
From: Naveen N. Rao <hidden>
Date: 2018-05-04 13:14:45
Subsystem:
function hooks (ftrace), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Madhavan Srinivasan, Linus Torvalds
On powerpc64 ABIv1, we are enabling syscall tracing for only ~20
syscalls. This is due to commit e145242ea0df6 ("syscalls/core,
syscalls/x86: Clean up syscall stub naming convention") which has
changed the syscall entry wrapper prefix from "SyS" to "__se_sys".
Update the logic for ABIv1 to not just skip the initial dot, but also
the "__se_sys" prefix.
Fixes: commit e145242ea0df6 ("syscalls/core, syscalls/x86: Clean up syscall stub naming convention")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <redacted>
---
arch/powerpc/include/asm/ftrace.h | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index f7a23c2dce74..731cb4314a42 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h@@ -71,13 +71,9 @@ struct dyn_arch_ftrace { #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) { - /* - * Compare the symbol name with the system call name. Skip the .sys or .SyS - * prefix from the symbol name and the sys prefix from the system call name and - * just match the rest. This is only needed on ppc64 since symbol names on - * 32bit do not start with a period so the generic function will work. - */ - return !strcmp(sym + 4, name + 3); + /* We need to skip past the initial dot, and the __se_sys alias */ + return !strcmp(sym + 1, name) || + (!strncmp(sym, ".__se_sys", 9) && !strcmp(sym + 6, name)); } #endif #endif /* CONFIG_FTRACE_SYSCALLS && !__ASSEMBLY__ */
--
2.17.0