From: wade_farnsworth@mentor•com (Wade Farnsworth)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2] ARM: support syscall tracing
Date: Wed, 15 Aug 2012 09:58:44 -0700 [thread overview]
Message-ID: <502BD544.70903@mentor.com> (raw)
In-Reply-To: <20120815162157.GJ29448@mudshark.cambridge.arm.com>
Will Deacon wrote:
> Hi Wade,
>
> On Wed, Aug 15, 2012 at 04:14:20PM +0100, Wade Farnsworth wrote:
>> diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
>> index 3e0fc5f..4e82fc1 100644
>> --- a/arch/arm/kernel/ptrace.c
>> +++ b/arch/arm/kernel/ptrace.c
>> @@ -30,6 +30,9 @@
>> #include<asm/pgtable.h>
>> #include<asm/traps.h>
>>
>> +#define CREATE_TRACE_POINTS
>> +#include<trace/events/syscalls.h>
>> +
>> #define REG_PC 15
>> #define REG_PSR 16
>> /*
>> @@ -918,7 +921,8 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
>> {
>> unsigned long ip;
>>
>> - if (!test_thread_flag(TIF_SYSCALL_TRACE))
>> + if (!test_thread_flag(TIF_SYSCALL_TRACE)&&
>> + !test_thread_flag(TIF_SYSCALL_TRACEPOINT))
>> return scno;
>
> Can we now remove this hunk?
>
>> current_thread_info()->syscall = scno;
>> @@ -930,10 +934,12 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
>> ip = regs->ARM_ip;
>> regs->ARM_ip = dir;
>>
>> - if (dir == PTRACE_SYSCALL_EXIT)
>> - tracehook_report_syscall_exit(regs, 0);
>> - else if (tracehook_report_syscall_entry(regs))
>> - current_thread_info()->syscall = -1;
>> + if (test_thread_flag(TIF_SYSCALL_TRACE)) {
>> + if (dir == PTRACE_SYSCALL_EXIT)
>> + tracehook_report_syscall_exit(regs, 0);
>> + else if (tracehook_report_syscall_entry(regs))
>> + current_thread_info()->syscall = -1;
>> + }
>
> and also this one?
>
We need to set current_thread_info()->syscall, since it's used in the
call to syscall_get_nr() in perf_syscall_{enter,exit}.
What about moving the setting of ->syscall to
syscall_trace_{enter,exit}? That would preserve ptrace_syscall_trace()
for the TIF_SYSCALL_TRACE case only, but ensure that the field is set
the TRACEPOINT case as well. Thoughts?
Thanks for the feedback!
Wade
next prev parent reply other threads:[~2012-08-15 16:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-15 15:14 [PATCH v2] ARM: support syscall tracing Wade Farnsworth
2012-08-15 16:21 ` Will Deacon
2012-08-15 16:58 ` Wade Farnsworth [this message]
2012-08-15 17:27 ` Will Deacon
2012-08-15 19:35 ` Wade Farnsworth
2012-08-15 20:21 ` Wade Farnsworth
2012-08-16 9:54 ` Will Deacon
2012-08-16 14:33 ` Wade Farnsworth
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