2020-11-10 22:14:09

by Andrey Konovalov

[permalink] [raw]
Subject: [PATCH v9 14/44] kasan: decode stack frame only with KASAN_STACK_ENABLE

Decoding routines aren't needed when CONFIG_KASAN_STACK_ENABLE is not
enabled. Currently only generic KASAN mode implements stack error
reporting.

No functional changes for software modes.

Signed-off-by: Andrey Konovalov <[email protected]>
Signed-off-by: Vincenzo Frascino <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
---
Change-Id: I084e3214f2b40dc0bef7c5a9fafdc6f5c42b06a2
---
mm/kasan/kasan.h | 6 ++
mm/kasan/report.c | 162 --------------------------------------
mm/kasan/report_generic.c | 162 ++++++++++++++++++++++++++++++++++++++
3 files changed, 168 insertions(+), 162 deletions(-)

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 3eff57e71ff5..d0cf61d4d70d 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -169,6 +169,12 @@ bool check_invalid_free(void *addr);
void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);

+#if defined(CONFIG_KASAN_GENERIC) && CONFIG_KASAN_STACK
+void print_address_stack_frame(const void *addr);
+#else
+static inline void print_address_stack_frame(const void *addr) { }
+#endif
+
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);
void kasan_report_invalid_free(void *object, unsigned long ip);
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index fff0c7befbfe..b18d193f7f58 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -211,168 +211,6 @@ static inline bool init_task_stack_addr(const void *addr)
sizeof(init_thread_union.stack));
}

-static bool __must_check tokenize_frame_descr(const char **frame_descr,
- char *token, size_t max_tok_len,
- unsigned long *value)
-{
- const char *sep = strchr(*frame_descr, ' ');
-
- if (sep == NULL)
- sep = *frame_descr + strlen(*frame_descr);
-
- if (token != NULL) {
- const size_t tok_len = sep - *frame_descr;
-
- if (tok_len + 1 > max_tok_len) {
- pr_err("KASAN internal error: frame description too long: %s\n",
- *frame_descr);
- return false;
- }
-
- /* Copy token (+ 1 byte for '\0'). */
- strlcpy(token, *frame_descr, tok_len + 1);
- }
-
- /* Advance frame_descr past separator. */
- *frame_descr = sep + 1;
-
- if (value != NULL && kstrtoul(token, 10, value)) {
- pr_err("KASAN internal error: not a valid number: %s\n", token);
- return false;
- }
-
- return true;
-}
-
-static void print_decoded_frame_descr(const char *frame_descr)
-{
- /*
- * We need to parse the following string:
- * "n alloc_1 alloc_2 ... alloc_n"
- * where alloc_i looks like
- * "offset size len name"
- * or "offset size len name:line".
- */
-
- char token[64];
- unsigned long num_objects;
-
- if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
- &num_objects))
- return;
-
- pr_err("\n");
- pr_err("this frame has %lu %s:\n", num_objects,
- num_objects == 1 ? "object" : "objects");
-
- while (num_objects--) {
- unsigned long offset;
- unsigned long size;
-
- /* access offset */
- if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
- &offset))
- return;
- /* access size */
- if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
- &size))
- return;
- /* name length (unused) */
- if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL))
- return;
- /* object name */
- if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
- NULL))
- return;
-
- /* Strip line number; without filename it's not very helpful. */
- strreplace(token, ':', '\0');
-
- /* Finally, print object information. */
- pr_err(" [%lu, %lu) '%s'", offset, offset + size, token);
- }
-}
-
-static bool __must_check get_address_stack_frame_info(const void *addr,
- unsigned long *offset,
- const char **frame_descr,
- const void **frame_pc)
-{
- unsigned long aligned_addr;
- unsigned long mem_ptr;
- const u8 *shadow_bottom;
- const u8 *shadow_ptr;
- const unsigned long *frame;
-
- 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);
- shadow_bottom = kasan_mem_to_shadow(end_of_stack(current));
-
- while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) {
- shadow_ptr--;
- mem_ptr -= KASAN_GRANULE_SIZE;
- }
-
- while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) {
- shadow_ptr--;
- mem_ptr -= KASAN_GRANULE_SIZE;
- }
-
- if (shadow_ptr < shadow_bottom)
- return false;
-
- frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE);
- if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) {
- pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n",
- frame[0]);
- return false;
- }
-
- *offset = (unsigned long)addr - (unsigned long)frame;
- *frame_descr = (const char *)frame[1];
- *frame_pc = (void *)frame[2];
-
- return true;
-}
-
-static void print_address_stack_frame(const void *addr)
-{
- unsigned long offset;
- const char *frame_descr;
- const void *frame_pc;
-
- if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
- 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);
- pr_err(" %pS\n", frame_pc);
-
- if (!frame_descr)
- return;
-
- print_decoded_frame_descr(frame_descr);
-}
-
static void print_address_description(void *addr, u8 tag)
{
struct page *page = kasan_addr_to_page(addr);
diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
index 7d5b9e5c7cfe..b543a1ed6078 100644
--- a/mm/kasan/report_generic.c
+++ b/mm/kasan/report_generic.c
@@ -16,6 +16,7 @@
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
#include <linux/slab.h>
#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
@@ -122,6 +123,167 @@ const char *get_bug_type(struct kasan_access_info *info)
return get_wild_bug_type(info);
}

+#if CONFIG_KASAN_STACK
+static bool __must_check tokenize_frame_descr(const char **frame_descr,
+ char *token, size_t max_tok_len,
+ unsigned long *value)
+{
+ const char *sep = strchr(*frame_descr, ' ');
+
+ if (sep == NULL)
+ sep = *frame_descr + strlen(*frame_descr);
+
+ if (token != NULL) {
+ const size_t tok_len = sep - *frame_descr;
+
+ if (tok_len + 1 > max_tok_len) {
+ pr_err("KASAN internal error: frame description too long: %s\n",
+ *frame_descr);
+ return false;
+ }
+
+ /* Copy token (+ 1 byte for '\0'). */
+ strlcpy(token, *frame_descr, tok_len + 1);
+ }
+
+ /* Advance frame_descr past separator. */
+ *frame_descr = sep + 1;
+
+ if (value != NULL && kstrtoul(token, 10, value)) {
+ pr_err("KASAN internal error: not a valid number: %s\n", token);
+ return false;
+ }
+
+ return true;
+}
+
+static void print_decoded_frame_descr(const char *frame_descr)
+{
+ /*
+ * We need to parse the following string:
+ * "n alloc_1 alloc_2 ... alloc_n"
+ * where alloc_i looks like
+ * "offset size len name"
+ * or "offset size len name:line".
+ */
+
+ char token[64];
+ unsigned long num_objects;
+
+ if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
+ &num_objects))
+ return;
+
+ pr_err("\n");
+ pr_err("this frame has %lu %s:\n", num_objects,
+ num_objects == 1 ? "object" : "objects");
+
+ while (num_objects--) {
+ unsigned long offset;
+ unsigned long size;
+
+ /* access offset */
+ if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
+ &offset))
+ return;
+ /* access size */
+ if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
+ &size))
+ return;
+ /* name length (unused) */
+ if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL))
+ return;
+ /* object name */
+ if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
+ NULL))
+ return;
+
+ /* Strip line number; without filename it's not very helpful. */
+ strreplace(token, ':', '\0');
+
+ /* Finally, print object information. */
+ pr_err(" [%lu, %lu) '%s'", offset, offset + size, token);
+ }
+}
+
+static bool __must_check get_address_stack_frame_info(const void *addr,
+ unsigned long *offset,
+ const char **frame_descr,
+ const void **frame_pc)
+{
+ unsigned long aligned_addr;
+ unsigned long mem_ptr;
+ const u8 *shadow_bottom;
+ const u8 *shadow_ptr;
+ const unsigned long *frame;
+
+ 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);
+ shadow_bottom = kasan_mem_to_shadow(end_of_stack(current));
+
+ while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) {
+ shadow_ptr--;
+ mem_ptr -= KASAN_GRANULE_SIZE;
+ }
+
+ while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) {
+ shadow_ptr--;
+ mem_ptr -= KASAN_GRANULE_SIZE;
+ }
+
+ if (shadow_ptr < shadow_bottom)
+ return false;
+
+ frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE);
+ if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) {
+ pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n",
+ frame[0]);
+ return false;
+ }
+
+ *offset = (unsigned long)addr - (unsigned long)frame;
+ *frame_descr = (const char *)frame[1];
+ *frame_pc = (void *)frame[2];
+
+ return true;
+}
+
+void print_address_stack_frame(const void *addr)
+{
+ unsigned long offset;
+ const char *frame_descr;
+ const void *frame_pc;
+
+ 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);
+ pr_err(" %pS\n", frame_pc);
+
+ if (!frame_descr)
+ return;
+
+ print_decoded_frame_descr(frame_descr);
+}
+#endif /* CONFIG_KASAN_STACK */
+
#define DEFINE_ASAN_REPORT_LOAD(size) \
void __asan_report_load##size##_noabort(unsigned long addr) \
{ \
--
2.29.2.222.g5d2a92d10f8-goog


2020-11-11 14:27:38

by Alexander Potapenko

[permalink] [raw]
Subject: Re: [PATCH v9 14/44] kasan: decode stack frame only with KASAN_STACK_ENABLE

On Tue, Nov 10, 2020 at 11:11 PM Andrey Konovalov <[email protected]> wrote:
>
> Decoding routines aren't needed when CONFIG_KASAN_STACK_ENABLE is not
> enabled. Currently only generic KASAN mode implements stack error
> reporting.
>
> No functional changes for software modes.
>
> Signed-off-by: Andrey Konovalov <[email protected]>
> Signed-off-by: Vincenzo Frascino <[email protected]>
> Reviewed-by: Marco Elver <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>

> ---
> Change-Id: I084e3214f2b40dc0bef7c5a9fafdc6f5c42b06a2
> ---
> mm/kasan/kasan.h | 6 ++
> mm/kasan/report.c | 162 --------------------------------------
> mm/kasan/report_generic.c | 162 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 168 insertions(+), 162 deletions(-)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 3eff57e71ff5..d0cf61d4d70d 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -169,6 +169,12 @@ bool check_invalid_free(void *addr);
> void *find_first_bad_addr(void *addr, size_t size);
> const char *get_bug_type(struct kasan_access_info *info);
>
> +#if defined(CONFIG_KASAN_GENERIC) && CONFIG_KASAN_STACK
> +void print_address_stack_frame(const void *addr);
> +#else
> +static inline void print_address_stack_frame(const void *addr) { }
> +#endif
> +
> bool kasan_report(unsigned long addr, size_t size,
> bool is_write, unsigned long ip);
> void kasan_report_invalid_free(void *object, unsigned long ip);
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index fff0c7befbfe..b18d193f7f58 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -211,168 +211,6 @@ static inline bool init_task_stack_addr(const void *addr)
> sizeof(init_thread_union.stack));
> }
>
> -static bool __must_check tokenize_frame_descr(const char **frame_descr,
> - char *token, size_t max_tok_len,
> - unsigned long *value)
> -{
> - const char *sep = strchr(*frame_descr, ' ');
> -
> - if (sep == NULL)
> - sep = *frame_descr + strlen(*frame_descr);
> -
> - if (token != NULL) {
> - const size_t tok_len = sep - *frame_descr;
> -
> - if (tok_len + 1 > max_tok_len) {
> - pr_err("KASAN internal error: frame description too long: %s\n",
> - *frame_descr);
> - return false;
> - }
> -
> - /* Copy token (+ 1 byte for '\0'). */
> - strlcpy(token, *frame_descr, tok_len + 1);
> - }
> -
> - /* Advance frame_descr past separator. */
> - *frame_descr = sep + 1;
> -
> - if (value != NULL && kstrtoul(token, 10, value)) {
> - pr_err("KASAN internal error: not a valid number: %s\n", token);
> - return false;
> - }
> -
> - return true;
> -}
> -
> -static void print_decoded_frame_descr(const char *frame_descr)
> -{
> - /*
> - * We need to parse the following string:
> - * "n alloc_1 alloc_2 ... alloc_n"
> - * where alloc_i looks like
> - * "offset size len name"
> - * or "offset size len name:line".
> - */
> -
> - char token[64];
> - unsigned long num_objects;
> -
> - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> - &num_objects))
> - return;
> -
> - pr_err("\n");
> - pr_err("this frame has %lu %s:\n", num_objects,
> - num_objects == 1 ? "object" : "objects");
> -
> - while (num_objects--) {
> - unsigned long offset;
> - unsigned long size;
> -
> - /* access offset */
> - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> - &offset))
> - return;
> - /* access size */
> - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> - &size))
> - return;
> - /* name length (unused) */
> - if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL))
> - return;
> - /* object name */
> - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> - NULL))
> - return;
> -
> - /* Strip line number; without filename it's not very helpful. */
> - strreplace(token, ':', '\0');
> -
> - /* Finally, print object information. */
> - pr_err(" [%lu, %lu) '%s'", offset, offset + size, token);
> - }
> -}
> -
> -static bool __must_check get_address_stack_frame_info(const void *addr,
> - unsigned long *offset,
> - const char **frame_descr,
> - const void **frame_pc)
> -{
> - unsigned long aligned_addr;
> - unsigned long mem_ptr;
> - const u8 *shadow_bottom;
> - const u8 *shadow_ptr;
> - const unsigned long *frame;
> -
> - 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);
> - shadow_bottom = kasan_mem_to_shadow(end_of_stack(current));
> -
> - while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) {
> - shadow_ptr--;
> - mem_ptr -= KASAN_GRANULE_SIZE;
> - }
> -
> - while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) {
> - shadow_ptr--;
> - mem_ptr -= KASAN_GRANULE_SIZE;
> - }
> -
> - if (shadow_ptr < shadow_bottom)
> - return false;
> -
> - frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE);
> - if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) {
> - pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n",
> - frame[0]);
> - return false;
> - }
> -
> - *offset = (unsigned long)addr - (unsigned long)frame;
> - *frame_descr = (const char *)frame[1];
> - *frame_pc = (void *)frame[2];
> -
> - return true;
> -}
> -
> -static void print_address_stack_frame(const void *addr)
> -{
> - unsigned long offset;
> - const char *frame_descr;
> - const void *frame_pc;
> -
> - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS))
> - 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);
> - pr_err(" %pS\n", frame_pc);
> -
> - if (!frame_descr)
> - return;
> -
> - print_decoded_frame_descr(frame_descr);
> -}
> -
> static void print_address_description(void *addr, u8 tag)
> {
> struct page *page = kasan_addr_to_page(addr);
> diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
> index 7d5b9e5c7cfe..b543a1ed6078 100644
> --- a/mm/kasan/report_generic.c
> +++ b/mm/kasan/report_generic.c
> @@ -16,6 +16,7 @@
> #include <linux/mm.h>
> #include <linux/printk.h>
> #include <linux/sched.h>
> +#include <linux/sched/task_stack.h>
> #include <linux/slab.h>
> #include <linux/stackdepot.h>
> #include <linux/stacktrace.h>
> @@ -122,6 +123,167 @@ const char *get_bug_type(struct kasan_access_info *info)
> return get_wild_bug_type(info);
> }
>
> +#if CONFIG_KASAN_STACK
> +static bool __must_check tokenize_frame_descr(const char **frame_descr,
> + char *token, size_t max_tok_len,
> + unsigned long *value)
> +{
> + const char *sep = strchr(*frame_descr, ' ');
> +
> + if (sep == NULL)
> + sep = *frame_descr + strlen(*frame_descr);
> +
> + if (token != NULL) {
> + const size_t tok_len = sep - *frame_descr;
> +
> + if (tok_len + 1 > max_tok_len) {
> + pr_err("KASAN internal error: frame description too long: %s\n",
> + *frame_descr);
> + return false;
> + }
> +
> + /* Copy token (+ 1 byte for '\0'). */
> + strlcpy(token, *frame_descr, tok_len + 1);
> + }
> +
> + /* Advance frame_descr past separator. */
> + *frame_descr = sep + 1;
> +
> + if (value != NULL && kstrtoul(token, 10, value)) {
> + pr_err("KASAN internal error: not a valid number: %s\n", token);
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static void print_decoded_frame_descr(const char *frame_descr)
> +{
> + /*
> + * We need to parse the following string:
> + * "n alloc_1 alloc_2 ... alloc_n"
> + * where alloc_i looks like
> + * "offset size len name"
> + * or "offset size len name:line".
> + */
> +
> + char token[64];
> + unsigned long num_objects;
> +
> + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> + &num_objects))
> + return;
> +
> + pr_err("\n");
> + pr_err("this frame has %lu %s:\n", num_objects,
> + num_objects == 1 ? "object" : "objects");
> +
> + while (num_objects--) {
> + unsigned long offset;
> + unsigned long size;
> +
> + /* access offset */
> + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> + &offset))
> + return;
> + /* access size */
> + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> + &size))
> + return;
> + /* name length (unused) */
> + if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL))
> + return;
> + /* object name */
> + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token),
> + NULL))
> + return;
> +
> + /* Strip line number; without filename it's not very helpful. */
> + strreplace(token, ':', '\0');
> +
> + /* Finally, print object information. */
> + pr_err(" [%lu, %lu) '%s'", offset, offset + size, token);
> + }
> +}
> +
> +static bool __must_check get_address_stack_frame_info(const void *addr,
> + unsigned long *offset,
> + const char **frame_descr,
> + const void **frame_pc)
> +{
> + unsigned long aligned_addr;
> + unsigned long mem_ptr;
> + const u8 *shadow_bottom;
> + const u8 *shadow_ptr;
> + const unsigned long *frame;
> +
> + 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);
> + shadow_bottom = kasan_mem_to_shadow(end_of_stack(current));
> +
> + while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) {
> + shadow_ptr--;
> + mem_ptr -= KASAN_GRANULE_SIZE;
> + }
> +
> + while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) {
> + shadow_ptr--;
> + mem_ptr -= KASAN_GRANULE_SIZE;
> + }
> +
> + if (shadow_ptr < shadow_bottom)
> + return false;
> +
> + frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE);
> + if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) {
> + pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n",
> + frame[0]);
> + return false;
> + }
> +
> + *offset = (unsigned long)addr - (unsigned long)frame;
> + *frame_descr = (const char *)frame[1];
> + *frame_pc = (void *)frame[2];
> +
> + return true;
> +}
> +
> +void print_address_stack_frame(const void *addr)
> +{
> + unsigned long offset;
> + const char *frame_descr;
> + const void *frame_pc;
> +
> + 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);
> + pr_err(" %pS\n", frame_pc);
> +
> + if (!frame_descr)
> + return;
> +
> + print_decoded_frame_descr(frame_descr);
> +}
> +#endif /* CONFIG_KASAN_STACK */
> +
> #define DEFINE_ASAN_REPORT_LOAD(size) \
> void __asan_report_load##size##_noabort(unsigned long addr) \
> { \
> --
> 2.29.2.222.g5d2a92d10f8-goog
>


--
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg