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authorAndrey Konovalov <andreyknvl@google.com>2020-12-22 12:02:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-22 12:55:08 -0800
commit4291e9ee618956eeae02b17f35b272193a6cda5a (patch)
treefe973136c2f533e4662a39de3f17189d44b9f1bf
parent2e903b91479782b7dedd869603423d77e079d3de (diff)
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kasan, arm64: print report from tag fault handler
Add error reporting for hardware tag-based KASAN. When CONFIG_KASAN_HW_TAGS is enabled, print KASAN report from the arm64 tag fault handler. SAS bits aren't set in ESR for all faults reported in EL1, so it's impossible to find out the size of the access the caused the fault. Adapt KASAN reporting code to handle this case. Link: https://lkml.kernel.org/r/b559c82b6a969afedf53b4694b475f0234067a1a.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm64/mm/fault.c14
-rw-r--r--mm/kasan/report.c11
2 files changed, 22 insertions, 3 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 46ac15249eca..3c40da479899 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -14,6 +14,7 @@
#include <linux/mm.h>
#include <linux/hardirq.h>
#include <linux/init.h>
+#include <linux/kasan.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/page-flags.h>
@@ -297,10 +298,23 @@ static void die_kernel_fault(const char *msg, unsigned long addr,
do_exit(SIGKILL);
}
+#ifdef CONFIG_KASAN_HW_TAGS
static void report_tag_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
+ bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0;
+
+ /*
+ * SAS bits aren't set for all faults reported in EL1, so we can't
+ * find out access size.
+ */
+ kasan_report(addr, 0, is_write, regs->pc);
}
+#else
+/* Tag faults aren't enabled without CONFIG_KASAN_HW_TAGS. */
+static inline void report_tag_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs) { }
+#endif
static void do_tag_recovery(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 9a6569a57ca2..929fcb2a0204 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -62,9 +62,14 @@ static void print_error_description(struct kasan_access_info *info)
{
pr_err("BUG: KASAN: %s in %pS\n",
get_bug_type(info), (void *)info->ip);
- pr_err("%s of size %zu at addr %px by task %s/%d\n",
- info->is_write ? "Write" : "Read", info->access_size,
- info->access_addr, current->comm, task_pid_nr(current));
+ if (info->access_size)
+ pr_err("%s of size %zu at addr %px by task %s/%d\n",
+ info->is_write ? "Write" : "Read", info->access_size,
+ info->access_addr, current->comm, task_pid_nr(current));
+ else
+ pr_err("%s at addr %px by task %s/%d\n",
+ info->is_write ? "Write" : "Read",
+ info->access_addr, current->comm, task_pid_nr(current));
}
static DEFINE_SPINLOCK(report_lock);