[PATCH mm 12/22] kasan: simplify kasan_find_first_bad_addr call sites

From: andrey . konovalov
Date: Wed Mar 02 2022 - 11:39:02 EST


From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

Move the addr_has_metadata() check into kasan_find_first_bad_addr().

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
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(-)

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index bb4c29b439b1..a0d4a9d3f933 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -444,10 +444,7 @@ static void __kasan_report(void *addr, size_t size, bool is_write,
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;
diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
index 7e03cca569a7..182239ca184c 100644
--- a/mm/kasan/report_generic.c
+++ b/mm/kasan/report_generic.c
@@ -34,8 +34,12 @@ void *kasan_find_first_bad_addr(void *addr, size_t size)
{
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;
}

diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c
index 5dbbbb930e7a..f3d3be614e4b 100644
--- a/mm/kasan/report_hw_tags.c
+++ b/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);
}

diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c
index 44577b8d47a7..68724ba3d814 100644
--- a/mm/kasan/report_sw_tags.c
+++ b/mm/kasan/report_sw_tags.c
@@ -35,8 +35,12 @@ void *kasan_find_first_bad_addr(void *addr, size_t size)
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;
}

--
2.25.1