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From: Dominik Brodowski <>
To: Steven Rostedt <>
Cc: LKML <>,
	Ingo Molnar <>,
	Thomas Gleixner <>,
	"H. Peter Anvin" <>,
	Arnaldo Carvalho de Melo <>,
Subject: Re: [PATCH v3] tracing/x86: Update syscall trace events to handle new prefixed syscall func names
Date: Wed, 18 Apr 2018 20:17:29 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <20180418114509.5a76847d@gandalf.local.home>

On Wed, Apr 18, 2018 at 11:45:09AM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <>
> Arnaldo noticed that the latest kernel is missing the syscall event system
> directory in x86. I bisected it down to d5a00528b58c ("syscalls/core,
> syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()").
> The system call trace events are special, as there is only one trace event
> for all system calls (the raw_syscalls). But a macro that wraps the system
> calls creates meta data for them that copies the name to find the system
> call that maps to the system call table (the number). At boot up, it does a
> kallsyms lookup of the system call table to find the function that maps to
> the meta data of the system call. If it does not find a function, then that
> system call is ignored.
> Because the x86 system calls had "__x64_", or "__ia32_" prefixed to the
> "sys" for the 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.
> Link:
> Reported-by: Arnaldo Carvalho de Melo <>
> Tested-by: Arnaldo Carvalho de Melo <>
> Fixes: d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()")
> Signed-off-by: Steven Rostedt (VMware) <>

Acked-by: Dominik Brodowski <>

  reply	other threads:[~2018-04-18 18:17 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-18 15:45 Steven Rostedt
2018-04-18 18:17 ` Dominik Brodowski [this message]
2018-04-18 18:19   ` Steven Rostedt
2018-04-19 11:15     ` Thomas Gleixner

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