Messages in this thread Patch in this message | | | Date | Mon, 15 Apr 2019 11:02:58 +0200 (CEST) | From | Thomas Gleixner <> | Subject | [patch V4 01/32] mm/slab: Fix broken stack trace storage |
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kstack_end() is broken on interrupt stacks as they are not guaranteed to be sized THREAD_SIZE and THREAD_SIZE aligned.
Use the stack tracer instead. Remove the pointless pointer increment at the end of the function while at it.
Fixes: 98eb235b7feb ("[PATCH] page unmapping debug") - History tree Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: linux-mm@kvack.org --- V4: Made the code simpler to understand (Andy) and make it actually compile --- mm/slab.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-)
--- a/mm/slab.c +++ b/mm/slab.c @@ -1470,33 +1470,31 @@ static bool is_debug_pagealloc_cache(str static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, unsigned long caller) { - int size = cachep->object_size; + int size = cachep->object_size / sizeof(unsigned long); addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; - if (size < 5 * sizeof(unsigned long)) + if (size < 5) return; *addr++ = 0x12345678; *addr++ = caller; *addr++ = smp_processor_id(); - size -= 3 * sizeof(unsigned long); + size -= 3; +#ifdef CONFIG_STACKTRACE { - unsigned long *sptr = &caller; - unsigned long svalue; - - while (!kstack_end(sptr)) { - svalue = *sptr++; - if (kernel_text_address(svalue)) { - *addr++ = svalue; - size -= sizeof(unsigned long); - if (size <= sizeof(unsigned long)) - break; - } - } + struct stack_trace trace = { + /* Leave one for the end marker below */ + .max_entries = size - 1, + .entries = addr, + .skip = 3, + }; + save_stack_trace(&trace); + addr += trace.nr_entries; } - *addr++ = 0x87654321; +#endif + *addr = 0x87654321; } static void slab_kernel_map(struct kmem_cache *cachep, void *objp,
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