From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: rearrange stack frame info in reports - Move printing stack frame info before printing page info. - Add object_is_on_stack() check to print_address_description() and add a corresponding WARNING to kasan_print_address_stack_frame(). This looks more in line with the rest of the checks in this function and also allows to avoid complicating code logic wrt line breaks. - Clean up comments related to get_address_stack_frame_info(). Link: https://lkml.kernel.org/r/1ee113a4c111df97d168c820b527cda77a3cac40.1646237226.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/report.c | 12 +++++++++--- mm/kasan/report_generic.c | 15 ++++----------- 2 files changed, 13 insertions(+), 14 deletions(-) --- a/mm/kasan/report.c~kasan-rearrange-stack-frame-info-in-reports +++ a/mm/kasan/report.c @@ -259,6 +259,15 @@ static void print_address_description(vo pr_err("\n"); } + if (object_is_on_stack(addr)) { + /* + * Currently, KASAN supports printing frame information only + * for accesses to the task's own stack. + */ + kasan_print_address_stack_frame(addr); + pr_err("\n"); + } + if (is_vmalloc_addr(addr)) { struct vm_struct *va = find_vm_area(addr); @@ -278,9 +287,6 @@ static void print_address_description(vo dump_page(page, "kasan: bad access detected"); pr_err("\n"); } - - kasan_print_address_stack_frame(addr); - pr_err("\n"); } static bool meta_row_is_guilty(const void *row, const void *addr) --- a/mm/kasan/report_generic.c~kasan-rearrange-stack-frame-info-in-reports +++ a/mm/kasan/report_generic.c @@ -211,6 +211,7 @@ static void print_decoded_frame_descr(co } } +/* Returns true only if the address is on the current task's stack. */ static bool __must_check get_address_stack_frame_info(const void *addr, unsigned long *offset, const char **frame_descr, @@ -224,13 +225,6 @@ static bool __must_check get_address_sta BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP)); - /* - * NOTE: We currently only support printing frame information for - * accesses to the task's own stack. - */ - if (!object_is_on_stack(addr)) - return false; - aligned_addr = round_down((unsigned long)addr, sizeof(long)); mem_ptr = round_down(aligned_addr, KASAN_GRANULE_SIZE); shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr); @@ -269,14 +263,13 @@ void kasan_print_address_stack_frame(con const char *frame_descr; const void *frame_pc; + if (WARN_ON(!object_is_on_stack(addr))) + return; + if (!get_address_stack_frame_info(addr, &offset, &frame_descr, &frame_pc)) return; - /* - * get_address_stack_frame_info only returns true if the given addr is - * on the current task's stack. - */ pr_err("\n"); pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n", addr, current->comm, task_pid_nr(current), offset); _
