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From: "Ian Munsie" <imunsie@au1.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: Andreas Dilger <adilger@dilger.ca>,
	Dave Kleikamp <shaggy@linux.vnet.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jiri Kosina <jkosina@suse.cz>, Jason Baron <jbaron@redhat.com>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Alexander Graf <agraf@suse.de>, Ingo Molnar <mingo@redhat.com>,
	Paul Mackerras <paulus@samba.org>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Scott Wood <scottwood@freescale.com>,
	Nathan Lynch <ntl@pobox.com>,
	Avantika Mathur <mathur@linux.vnet.ibm.com>,
	David Gibson <dwg@au1.ibm.com>,
	Andreas Schwab <schwab@linux-m68k.org>,
	Namhyung Kim <namhyung@gmail.com>,
	Ian Munsie <imunsie@au1.ibm.com>,
	linux-doc@vger.kernel.org (open list:DOCUMENTATION)
Subject: [PATCH 3/6] ftrace syscalls: Make arch_syscall_addr weak
Date: Thu,  3 Feb 2011 14:27:22 +1100	[thread overview]
Message-ID: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com> (raw)
In-Reply-To: <1296703645-18718-1-git-send-email-imunsie@au1.ibm.com>

From: Ian Munsie <imunsie@au1.ibm.com>

Some architectures use non-trivial system call tables and will not work
with the generic arch_syscall_addr code. For example, PowerPC64 uses a
table of twin long longs.

This patch makes the generic arch_syscall_addr weak to allow
architectures with non-trivial system call tables to override it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
---
 Documentation/trace/ftrace-design.txt |    3 +++
 kernel/trace/trace_syscalls.c         |    2 +-
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index dc52bd4..6fca17b 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -247,6 +247,9 @@ You need very few things to get the syscalls tracing in an arch.
 - Support the TIF_SYSCALL_TRACEPOINT thread flags.
 - Put the trace_sys_enter() and trace_sys_exit() tracepoints calls from ptrace
   in the ptrace syscalls tracing path.
+- If the system call table on this arch is more complicated than a simple array
+  of addresses of the system calls, implement an arch_syscall_addr to return
+  the address of a given system call.
 - Tag this arch as HAVE_SYSCALL_TRACEPOINTS.
 
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 1a6e8dd..33360b9 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -445,7 +445,7 @@ int init_syscall_trace(struct ftrace_event_call *call)
 	return id;
 }
 
-unsigned long __init arch_syscall_addr(int nr)
+unsigned long __init __weak arch_syscall_addr(int nr)
 {
 	return (unsigned long)sys_call_table[nr];
 }
-- 
1.7.2.3


  parent reply	other threads:[~2011-02-03  3:27 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-03  3:27 PowerPC, ftrace: Add PPC raw syscall tracepoints & ftrace fixes (mimimal subset only) v4 Ian Munsie
2011-02-03  3:27 ` [PATCH 1/6] ftrace syscalls: don't add events for unmapped syscalls Ian Munsie
2011-02-17 14:58   ` [tip:perf/core] tracing/syscalls: Don't " tip-bot for Ian Munsie
2011-02-03  3:27 ` [PATCH 2/6] ftrace syscalls: Convert redundant syscall_nr checks into WARN_ON Ian Munsie
2011-02-17 14:59   ` [tip:perf/core] tracing/syscalls: " tip-bot for Ian Munsie
2011-02-03  3:27 ` Ian Munsie [this message]
2011-02-17 14:59   ` [tip:perf/core] tracing/syscalls: Make arch_syscall_addr weak tip-bot for Ian Munsie
2011-02-03  3:27 ` [PATCH 4/6] ftrace syscalls: Allow arch specific syscall symbol matching Ian Munsie
2011-02-17 14:59   ` [tip:perf/core] tracing/syscalls: " tip-bot for Ian Munsie
2011-02-03  3:27 ` [PATCH 5/6] ftrace, powerpc: Implement raw syscall tracepoints on PowerPC Ian Munsie
2011-02-08  2:10   ` Steven Rostedt
2011-02-08 10:07     ` Benjamin Herrenschmidt
2011-02-08 16:54       ` Steven Rostedt
2011-02-03  3:27 ` [PATCH 6/6] ftrace syscalls: Early terminate search for sys_ni_syscall Ian Munsie
2011-02-17 15:00   ` [tip:perf/core] tracing/syscalls: " tip-bot for Ian Munsie
2011-02-08  2:10 ` PowerPC, ftrace: Add PPC raw syscall tracepoints & ftrace fixes (mimimal subset only) v4 Steven Rostedt
  -- strict thread matches above, loose matches on Subject: below --
2011-02-02  7:11 PowerPC, ftrace: Add PPC raw syscall tracepoints & ftrace fixes (mimimal subset only) v3 Ian Munsie
2011-02-02  7:11 ` [PATCH 3/6] ftrace syscalls: Make arch_syscall_addr weak Ian Munsie
     [not found] <1291696151-4336-1-git-send-email-imunsie@au1.ibm.com>
2010-12-07  4:29 ` Ian Munsie

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