From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Subject: mm/slab.c: do not hash pointers when debugging slab If CONFIG_DEBUG_SLAB/CONFIG_DEBUG_SLAB_LEAK are enabled, the slab code prints extra debug information when e.g. corruption is detected. This includes pointers, which are not very useful when hashed. Fix this by using %px to print unhashed pointers instead where it makes sense, and by removing the printing of a last user pointer referring to code. [geert+renesas@xxxxxxxxx: v2] Link: http://lkml.kernel.org/r/1513179267-2509-1-git-send-email-geert+renesas@xxxxxxxxx Link: http://lkml.kernel.org/r/1512641861-5113-1-git-send-email-geert+renesas@xxxxxxxxx Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: "Tobin C . Harding" <me@xxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff -puN mm/slab.c~mm-slab-do-not-hash-pointers-when-debugging-slab mm/slab.c --- a/mm/slab.c~mm-slab-do-not-hash-pointers-when-debugging-slab +++ a/mm/slab.c @@ -1584,11 +1584,8 @@ static void print_objinfo(struct kmem_ca *dbg_redzone2(cachep, objp)); } - if (cachep->flags & SLAB_STORE_USER) { - pr_err("Last user: [<%p>](%pSR)\n", - *dbg_userword(cachep, objp), - *dbg_userword(cachep, objp)); - } + if (cachep->flags & SLAB_STORE_USER) + pr_err("Last user: (%pSR)\n", *dbg_userword(cachep, objp)); realobj = (char *)objp + obj_offset(cachep); size = cachep->object_size; for (i = 0; i < size && lines; i += 16, lines--) { @@ -1621,7 +1618,7 @@ static void check_poison_obj(struct kmem /* Mismatch ! */ /* Print header */ if (lines == 0) { - pr_err("Slab corruption (%s): %s start=%p, len=%d\n", + pr_err("Slab corruption (%s): %s start=%px, len=%d\n", print_tainted(), cachep->name, realobj, size); print_objinfo(cachep, objp, 0); @@ -1650,13 +1647,13 @@ static void check_poison_obj(struct kmem if (objnr) { objp = index_to_obj(cachep, page, objnr - 1); realobj = (char *)objp + obj_offset(cachep); - pr_err("Prev obj: start=%p, len=%d\n", realobj, size); + pr_err("Prev obj: start=%px, len=%d\n", realobj, size); print_objinfo(cachep, objp, 2); } if (objnr + 1 < cachep->num) { objp = index_to_obj(cachep, page, objnr + 1); realobj = (char *)objp + obj_offset(cachep); - pr_err("Next obj: start=%p, len=%d\n", realobj, size); + pr_err("Next obj: start=%px, len=%d\n", realobj, size); print_objinfo(cachep, objp, 2); } } @@ -2608,7 +2605,7 @@ static void slab_put_obj(struct kmem_cac /* Verify double free bug */ for (i = page->active; i < cachep->num; i++) { if (get_free_obj(page, i) == objnr) { - pr_err("slab: double free detected in cache '%s', objp %p\n", + pr_err("slab: double free detected in cache '%s', objp %px\n", cachep->name, objp); BUG(); } @@ -2772,7 +2769,7 @@ static inline void verify_redzone_free(s else slab_error(cache, "memory outside object was overwritten"); - pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n", + pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n", obj, redzone1, redzone2); } @@ -3078,7 +3075,7 @@ static void *cache_alloc_debugcheck_afte if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) { slab_error(cachep, "double free, or memory outside object was overwritten"); - pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n", + pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n", objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); } @@ -3091,7 +3088,7 @@ static void *cache_alloc_debugcheck_afte cachep->ctor(objp); if (ARCH_SLAB_MINALIGN && ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { - pr_err("0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", + pr_err("0x%px: not aligned to ARCH_SLAB_MINALIGN=%d\n", objp, (int)ARCH_SLAB_MINALIGN); } return objp; @@ -4283,7 +4280,7 @@ static void show_symbol(struct seq_file return; } #endif - seq_printf(m, "%p", (void *)address); + seq_printf(m, "%px", (void *)address); } static int leaks_show(struct seq_file *m, void *p) _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
