Le 05/12/2022 à 19:19, Michael Jeanson a écrit : > [Vous ne recevez pas souvent de courriers de mjeanson@xxxxxxxxxxxx. > Découvrez pourquoi ceci est important à > https://aka.ms/LearnAboutSenderIdentification ] > > On 2022-12-05 00:34, Michael Ellerman wrote: >> Michael Jeanson <mjeanson@xxxxxxxxxxxx> 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? If you are using a ppc32 config, CONFIG_PPC64_ELF_ABI_V1 won't be set, so it doesn't matter whether this change is there or not. You should try corenet64_smp_defconfig if you want CONFIG_PPC64_ELF_ABI_V1 to be set. You can also use ppc64_defconfig, that's a different platform but it also has CONFIG_PPC64_ELF_ABI_V1. Christophe > > Thanks for looking into this. > >> >> >>> 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 >
