[PATCH] powerpc/ftrace: fix syscall tracing on PPC64_ELF_ABI_V1

From: Michael Jeanson
Date: Thu Dec 01 2022 - 11:20:30 EST


In v5.7 the powerpc syscall entry/exit logic was rewritten in C, on
PPC64_ELF_ABI_V1 this resulted in the symbols in the syscall table
changing from their dot prefixed variant to the non-prefixed ones.

Since ftrace prefixes a dot to the syscall names when matching them to
build its syscall event list, this resulted in no syscall events being
available.

Remove the PPC64_ELF_ABI_V1 specific version of
arch_syscall_match_sym_name to have the same behavior across all powerpc
variants.

Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Cc: stable@xxxxxxxxxxxxxxx # v5.7+
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Michal Suchanek <msuchanek@xxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Michael Jeanson <mjeanson@xxxxxxxxxxxx>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
---
arch/powerpc/include/asm/ftrace.h | 12 ------------
1 file changed, 12 deletions(-)

diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index 3cee7115441b..e3d1f377bc5b 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -64,17 +64,6 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
* those.
*/
#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
-#ifdef CONFIG_PPC64_ELF_ABI_V1
-static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
-{
- /* 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)) ||
- (!strncmp(sym, ".ppc_", 5) && !strcmp(sym + 5, name + 4)) ||
- (!strncmp(sym, ".ppc32_", 7) && !strcmp(sym + 7, name + 4)) ||
- (!strncmp(sym, ".ppc64_", 7) && !strcmp(sym + 7, name + 4));
-}
-#else
static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
{
return !strcmp(sym, name) ||
@@ -83,7 +72,6 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
(!strncmp(sym, "ppc32_", 6) && !strcmp(sym + 6, name + 4)) ||
(!strncmp(sym, "ppc64_", 6) && !strcmp(sym + 6, name + 4));
}
-#endif /* CONFIG_PPC64_ELF_ABI_V1 */
#endif /* CONFIG_FTRACE_SYSCALLS */

#if defined(CONFIG_PPC64) && defined(CONFIG_FUNCTION_TRACER)
--
2.34.1