On 6 May 2014, at 19:15, Sasha Levin <sasha.levin@xxxxxxxxxx> 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@xxxxxxx> >>>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >>> >>> 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href