Messages in this thread | | | Date | Wed, 28 Nov 2018 08:55:55 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH] arm64: ftrace: Fix to enable syscall events on arm64 |
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Hi Will,
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.
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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