Messages in this thread | | | Date | Mon, 5 Dec 2022 13:19:34 -0500 | Subject | Re: [PATCH] powerpc/ftrace: fix syscall tracing on PPC64_ELF_ABI_V1 | From | Michael Jeanson <> |
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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
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