linux-kernel - Re: [PATCH 0/3] stop OProfile calling arch_exit when arch

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100831110152.GD22783@erda.amd.com>
Date:	Tue, 31 Aug 2010 13:01:52 +0200
From:	Robert Richter <robert.richter@....com>
To:	Will Deacon <will.deacon@....com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Matt Fleming <matt@...sole-pimps.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...e.hu>
Subject: Re: [PATCH 0/3] stop OProfile calling arch_exit when arch_init
 fails

On 29.08.10 14:51:58, Will Deacon wrote:
> These patches remove the oprofile_arch_exit call from oprofile_init,
> allowing architectures that perform memory allocation in their init
> functions to be simplified. This requires some changes to the ARM and
> x86 OProfile backends to ensure that their init functions clean up
> after themselves if they fail.
> 
> This is required for Matt's combined OProfile/Perf driver which will
> be shared between all architectures.
> 
> Patches taken against tip/master.
> 
> Cc: Robert Richter <robert.richter@....com>
> Cc: Matt Fleming <matt@...sole-pimps.org>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Ingo Molnar <mingo@...e.hu>
> 
> Will Deacon (3):
>   oprofile: don't call arch exit code from init code on failure
>   ARM: oprofile: fix and simplify init/exit functions
>   x86: oprofile: fix oprofile_arch_init behaviour on failure
> 
>  arch/arm/oprofile/common.c |   47 +++++++++++++++++++++++--------------------
>  arch/x86/oprofile/init.c   |   26 ++++++++++++++----------
>  drivers/oprofile/oprof.c   |   11 +--------
>  3 files changed, 42 insertions(+), 42 deletions(-)

I have applied patch #1 and #2 to

 git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile.git core

with some small modifications:

Patch #1: Commit message, x86 removed.
Patch #2: Order of freeing memory:

+out:
+       if (ret) {
+               for_each_possible_cpu(cpu)
+                       kfree(perf_events[cpu]);
+               kfree(counter_config);
+       }
+

There is also the patch below on top of it.

Thanks Will,

-Robert

--

>From 4cbe75be5c6ae86bdc7daec864eeb2dfd66f48bb Mon Sep 17 00:00:00 2001
From: Robert Richter <robert.richter@....com>
Date: Mon, 30 Aug 2010 18:21:55 +0200
Subject: [PATCH] oprofile, arm: initialize perf_event pointers with NULL

The pointers must be NULL'ed to avoid double-freeing the pointers in
rare cases during reinitialization.

Signed-off-by: Robert Richter <robert.richter@....com>
---
 arch/arm/oprofile/common.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index c3652f7..d660cb8 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -351,6 +351,8 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
 	int cpu, ret = 0;
 
+	memset(&perf_events, 0, sizeof(perf_events));
+
 	perf_num_counters = armpmu_get_max_events();
 
 	counter_config = kcalloc(perf_num_counters,
-- 
1.7.1.1


-- 
Advanced Micro Devices, Inc.
Operating System Research Center

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/