Messages in this thread | | | Date | Wed, 28 Nov 2018 12:05:02 +0000 | From | Will Deacon <> | Subject | Re: [PATCH] arm64: ftrace: Fix to enable syscall events on arm64 |
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Hi Masami,
On Wed, Nov 28, 2018 at 08:55:55AM +0900, Masami Hiramatsu wrote: > On Tue, 27 Nov 2018 13:18:59 -0500 > Steven Rostedt <rostedt@goodmis.org> wrote: > > > On Tue, 27 Nov 2018 16:58:49 +0000 > > Will Deacon <will.deacon@arm.com> wrote: > > > > > This looks fine to me, but I'm curious about whether this is supposed to > > > work with compat syscalls as well, where the prefix is "__arm64_compat_". > > > > > > If we broadly follow the x86 lead, we'd have: > > > > > > return (!strncmp(sym, "__arm64_", 8) && !strcmp(sym + 8, name)) || > > > (!strncmp(sym, "__arm64_compat_", 15) && !strcmp(sym + 15, name)); > > > > > > Do we need to handle compat (i.e. 32-bit) tasks here? > > > > Only if you want to trace compat syscalls as well ;-) > > Actually I thought about that, but I found below comment in > arch/arm64/include/asm/ftrace.h > > * Because AArch32 mode does not share the same syscall table with AArch64, > * tracing compat syscalls may result in reporting bogus syscalls or even > * hang-up, so just do not trace them. > > That's why I dropped compat syscall support.
Ok! Then please add a comment to arch_syscall_match_sym_name() along those lines, and you can add my ack:
Acked-by: Will Deacon <will.deacon@arm.com>
Thanks,
Will
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