On 2022-12-05 00:34, Michael Ellerman wrote:
Michael Jeanson mjeanson@efficios.com writes:
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.
This doesn't seem to work for me.
Event with it applied I still don't see anything in /sys/kernel/debug/tracing/events/syscalls
Did we break it in some other way recently?
cheers
I've just tried this change on top of v6.1-rc8 in qemu with a base config of 'corenet32_smp_defconfig' and these options on top:
CONFIG_FTRACE=y CONFIG_FTRACE_SYSCALLS=y
And I can trace syscalls with ftrace.
What kernel tree and config are you using?
Thanks for looking into this.
Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C") Cc: stable@vger.kernel.org # v5.7+ Cc: Steven Rostedt rostedt@goodmis.org Cc: Masami Hiramatsu mhiramat@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Nicholas Piggin npiggin@gmail.com Cc: Christophe Leroy christophe.leroy@csgroup.eu Cc: Michal Suchanek msuchanek@suse.de Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Michael Jeanson mjeanson@efficios.com Reviewed-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com
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