From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: simplify kasan_find_first_bad_addr call sites Move the addr_has_metadata() check into kasan_find_first_bad_addr(). Link: https://lkml.kernel.org/r/a49576f7a23283d786ba61579cb0c5057e8f0b9b.1646237226.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: 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 | 5 +---- mm/kasan/report_generic.c | 4 ++++ mm/kasan/report_hw_tags.c | 1 + mm/kasan/report_sw_tags.c | 4 ++++ 4 files changed, 10 insertions(+), 4 deletions(-) --- a/mm/kasan/report.c~kasan-simplify-kasan_find_first_bad_addr-call-sites +++ a/mm/kasan/report.c @@ -444,10 +444,7 @@ static void __kasan_report(void *addr, s start_report(&flags, true); info.access_addr = addr; - if (addr_has_metadata(addr)) - info.first_bad_addr = kasan_find_first_bad_addr(addr, size); - else - info.first_bad_addr = addr; + info.first_bad_addr = kasan_find_first_bad_addr(addr, size); info.access_size = size; info.is_write = is_write; info.ip = ip; --- a/mm/kasan/report_generic.c~kasan-simplify-kasan_find_first_bad_addr-call-sites +++ a/mm/kasan/report_generic.c @@ -34,8 +34,12 @@ void *kasan_find_first_bad_addr(void *ad { void *p = addr; + if (!addr_has_metadata(p)) + return p; + while (p < addr + size && !(*(u8 *)kasan_mem_to_shadow(p))) p += KASAN_GRANULE_SIZE; + return p; } --- a/mm/kasan/report_hw_tags.c~kasan-simplify-kasan_find_first_bad_addr-call-sites +++ a/mm/kasan/report_hw_tags.c @@ -17,6 +17,7 @@ void *kasan_find_first_bad_addr(void *addr, size_t size) { + /* Return the same value regardless of whether addr_has_metadata(). */ return kasan_reset_tag(addr); } --- a/mm/kasan/report_sw_tags.c~kasan-simplify-kasan_find_first_bad_addr-call-sites +++ a/mm/kasan/report_sw_tags.c @@ -36,8 +36,12 @@ void *kasan_find_first_bad_addr(void *ad void *p = kasan_reset_tag(addr); void *end = p + size; + if (!addr_has_metadata(p)) + return p; + while (p < end && tag == *(u8 *)kasan_mem_to_shadow(p)) p += KASAN_GRANULE_SIZE; + return p; } _
