On Tue, 17 Apr 2018 18:10:29 +0200 Dominik Brodowski <[email protected]> wrote:
> > Because the x86 system calls had "__x86_" appended to the "sys" for the > > __x64 actually. Heh, I constantly make that mistake. Hmm, OK, I need to look at this a bit more. If this is x64, then there's probably syscalls (on 32 bit), that don't have that. It should probably include more checks. Something like: return !strcmp(sym + 9, name + 3) || !strcmp(sym + 3, name + 3); > > > names, they do not match the default compare algorithm. As this was a > > problem for power pc, the algorithm can be overwritten by the architecture. > > The solution is to have x86 have its own algorithm to do the compare and > > this brings back the system call trace events. > > this lets me wonder *which* syscall "function" should be included in this > directory. Is it really the stub (__x64_sys_waitid, for example), or better > the sign-extending C function (__se_sys_waitid) which then calls an > internal helper (__do_sys_waitid). An additional advantage: > __se_sys_waitid would be available on x86 and, AFAICS, on all other archs. It should include anything that uses the "SYSCALL_DEFINE#()" macros. > > > Reported-by: Arnaldo Carvalho de Melo <[email protected]> > > Fixes: d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct > > pt_regs-based sys_*() to __x64_sys_*()") > > Signed-off-by: Steven Rostedt (VMware) <[email protected]> > > --- > > arch/x86/include/asm/ftrace.h | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h > > index 09ad88572746..c30b3fac20ae 100644 > > --- a/arch/x86/include/asm/ftrace.h > > +++ b/arch/x86/include/asm/ftrace.h > > @@ -31,6 +31,16 @@ static inline unsigned long ftrace_call_adjust(unsigned > > long addr) > > return addr; > > } > > > > +#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 > > + * "__x64_sys" prefix. > > + */ > > + return !strcmp(sym + 9, name + 3); > > +} > > What are the first three chars you skip for *name? "sys_" -- Steve > > Thanks, > Dominik
