summary refs log tree commit diff
path: root/mm/kfence/core.c
diff options
context:
space:
mode:
authorMarco Elver <elver@google.com>2021-02-25 17:19:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-26 09:41:02 -0800
commitd438fabce7860df3cb9337776be6f90b59ced8ed (patch)
tree912661af5be56d1fe1b7428a49e1b176e4b50515 /mm/kfence/core.c
parent840b239863449f27bf7522deb81e6746fbfbfeaf (diff)
downloadlinux-d438fabce7860df3cb9337776be6f90b59ced8ed.tar.gz
kfence: use pt_regs to generate stack trace on faults
Instead of removing the fault handling portion of the stack trace based on
the fault handler's name, just use struct pt_regs directly.

Change kfence_handle_page_fault() to take a struct pt_regs, and plumb it
through to kfence_report_error() for out-of-bounds, use-after-free, or
invalid access errors, where pt_regs is used to generate the stack trace.

If the kernel is a DEBUG_KERNEL, also show registers for more information.

Link: https://lkml.kernel.org/r/20201105092133.2075331-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kfence/core.c')
-rw-r--r--mm/kfence/core.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index d6a32c13336b..61c76670a7a9 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -216,7 +216,7 @@ static inline bool check_canary_byte(u8 *addr)
 		return true;
 
 	atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]);
-	kfence_report_error((unsigned long)addr, addr_to_metadata((unsigned long)addr),
+	kfence_report_error((unsigned long)addr, NULL, addr_to_metadata((unsigned long)addr),
 			    KFENCE_ERROR_CORRUPTION);
 	return false;
 }
@@ -351,7 +351,7 @@ static void kfence_guarded_free(void *addr, struct kfence_metadata *meta, bool z
 	if (meta->state != KFENCE_OBJECT_ALLOCATED || meta->addr != (unsigned long)addr) {
 		/* Invalid or double-free, bail out. */
 		atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]);
-		kfence_report_error((unsigned long)addr, meta, KFENCE_ERROR_INVALID_FREE);
+		kfence_report_error((unsigned long)addr, NULL, meta, KFENCE_ERROR_INVALID_FREE);
 		raw_spin_unlock_irqrestore(&meta->lock, flags);
 		return;
 	}
@@ -766,7 +766,7 @@ void __kfence_free(void *addr)
 		kfence_guarded_free(addr, meta, false);
 }
 
-bool kfence_handle_page_fault(unsigned long addr)
+bool kfence_handle_page_fault(unsigned long addr, struct pt_regs *regs)
 {
 	const int page_index = (addr - (unsigned long)__kfence_pool) / PAGE_SIZE;
 	struct kfence_metadata *to_report = NULL;
@@ -829,11 +829,11 @@ bool kfence_handle_page_fault(unsigned long addr)
 
 out:
 	if (to_report) {
-		kfence_report_error(addr, to_report, error_type);
+		kfence_report_error(addr, regs, to_report, error_type);
 		raw_spin_unlock_irqrestore(&to_report->lock, flags);
 	} else {
 		/* This may be a UAF or OOB access, but we can't be sure. */
-		kfence_report_error(addr, NULL, KFENCE_ERROR_INVALID);
+		kfence_report_error(addr, regs, NULL, KFENCE_ERROR_INVALID);
 	}
 
 	return kfence_unprotect(addr); /* Unprotect and let access proceed. */