| Message ID | 20140506170549.GM23957@arm.com |
|---|---|
| State | New |
| Headers | show |
On 05/06/2014 01:05 PM, Catalin Marinas wrote: > On Tue, May 06, 2014 at 04:20:27PM +0100, Sasha Levin wrote: >> On 05/02/2014 09:41 AM, Catalin Marinas wrote: >>> Currently, kmemleak_early_log is disabled at the beginning of the >>> kmemleak_init() function, before the full kmemleak tracing is actually >>> enabled. In this small window, kmem_cache_create() is called by kmemleak >>> which triggers additional memory allocation that are not traced. This >>> patch moves the kmemleak_early_log disabling further down and at the >>> same time with full kmemleak enabling. >>> >>> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> >>> Cc: Andrew Morton <akpm@linux-foundation.org> >> >> This patch makes the kernel die during the boot process: >> >> [ 24.471801] BUG: unable to handle kernel paging request at ffffffff922f2b93 >> [ 24.472496] IP: [<ffffffff922f2b93>] log_early+0x0/0xcd > > Thanks for reporting this. I assume you run with > CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF enabled and kmemleak_early_log remains > set even though kmemleak is not in use. > > Does the patch below fix it? Nope, that didn't help as I don't have DEBUG_KMEMLEAK_DEFAULT_OFF enabled. For reference: $ cat .config | grep KMEMLEAK CONFIG_HAVE_DEBUG_KMEMLEAK=y CONFIG_DEBUG_KMEMLEAK=y CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=400 # CONFIG_DEBUG_KMEMLEAK_TEST is not set # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 6 May 2014, at 19:15, Sasha Levin <sasha.levin@oracle.com> wrote: > On 05/06/2014 01:05 PM, Catalin Marinas wrote: >> On Tue, May 06, 2014 at 04:20:27PM +0100, Sasha Levin wrote: >>> On 05/02/2014 09:41 AM, Catalin Marinas wrote: >>>> Currently, kmemleak_early_log is disabled at the beginning of the >>>> kmemleak_init() function, before the full kmemleak tracing is actually >>>> enabled. In this small window, kmem_cache_create() is called by kmemleak >>>> which triggers additional memory allocation that are not traced. This >>>> patch moves the kmemleak_early_log disabling further down and at the >>>> same time with full kmemleak enabling. >>>> >>>> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> >>>> Cc: Andrew Morton <akpm@linux-foundation.org> >>> >>> This patch makes the kernel die during the boot process: >>> >>> [ 24.471801] BUG: unable to handle kernel paging request at ffffffff922f2b93 >>> [ 24.472496] IP: [<ffffffff922f2b93>] log_early+0x0/0xcd >> >> Thanks for reporting this. I assume you run with >> CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF enabled and kmemleak_early_log remains >> set even though kmemleak is not in use. >> >> Does the patch below fix it? > > Nope, that didn't help as I don't have DEBUG_KMEMLEAK_DEFAULT_OFF enabled. > > For reference: > > $ cat .config | grep KMEMLEAK > CONFIG_HAVE_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK=y > CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=400 > # CONFIG_DEBUG_KMEMLEAK_TEST is not set > # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set I assume your dmesg shows some kmemleak error during boot? I’ll send another patch tomorrow. The code around kmemleak_init was changed by commit 8910ae896c8c (kmemleak: change some global variables to int). It looks like it wasn’t just a simple conversion but slightly changed the kmemleak_early_log logic which led to false positives for the kmemleak cache objects and that’s what my patch was trying to solve. The failure is caused by kmemleak_alloc() still calling log_early() much later after the __init section has been freed because kmemleak_early_log hasn’t been set to 0 (the default off is one path, another is the kmemleak_error path). Catalin-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 05/06/2014 05:52 PM, Catalin Marinas wrote: > On 6 May 2014, at 19:15, Sasha Levin <sasha.levin@oracle.com> wrote: >> On 05/06/2014 01:05 PM, Catalin Marinas wrote: >>> On Tue, May 06, 2014 at 04:20:27PM +0100, Sasha Levin wrote: >>>> On 05/02/2014 09:41 AM, Catalin Marinas wrote: >>>>> Currently, kmemleak_early_log is disabled at the beginning of the >>>>> kmemleak_init() function, before the full kmemleak tracing is actually >>>>> enabled. In this small window, kmem_cache_create() is called by kmemleak >>>>> which triggers additional memory allocation that are not traced. This >>>>> patch moves the kmemleak_early_log disabling further down and at the >>>>> same time with full kmemleak enabling. >>>>> >>>>> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> >>>>> Cc: Andrew Morton <akpm@linux-foundation.org> >>>> >>>> This patch makes the kernel die during the boot process: >>>> >>>> [ 24.471801] BUG: unable to handle kernel paging request at ffffffff922f2b93 >>>> [ 24.472496] IP: [<ffffffff922f2b93>] log_early+0x0/0xcd >>> >>> Thanks for reporting this. I assume you run with >>> CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF enabled and kmemleak_early_log remains >>> set even though kmemleak is not in use. >>> >>> Does the patch below fix it? >> >> Nope, that didn't help as I don't have DEBUG_KMEMLEAK_DEFAULT_OFF enabled. >> >> For reference: >> >> $ cat .config | grep KMEMLEAK >> CONFIG_HAVE_DEBUG_KMEMLEAK=y >> CONFIG_DEBUG_KMEMLEAK=y >> CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=400 >> # CONFIG_DEBUG_KMEMLEAK_TEST is not set >> # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set > > I assume your dmesg shows some kmemleak error during boot? I’ll send > another patch tomorrow. Besides the BUG, I have these kmemleak messages: $ grep kmemleak out.txt [ 0.000000] kmemleak: Kernel memory leak detector disabled [ 0.000000] kmemleak: Early log buffer exceeded (2742), please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 0cd6aabd45a0..e7f74091c024 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1811,6 +1811,7 @@ void __init kmemleak_init(void) #ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF if (!kmemleak_skip_disable) { + kmemleak_early_log = 0; kmemleak_disable(); return; }