The patch titled
Subject: kasan, arm64: print report from tag fault handler
has been added to the -mm tree. Its filename is
kasan-arm64-print-report-from-tag-fault-handler.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-arm64-print-report-from-tag-fault-handler.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-arm64-print-report-from-tag-fault-handler.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: 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/fe78d723ba64456d68754a944fa93fe4a25c730f.1605046192.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/mm/fault.c | 14 ++++++++++++++
mm/kasan/report.c | 11 ++++++++---
2 files changed, 22 insertions(+), 3 deletions(-)
--- a/arch/arm64/mm/fault.c~kasan-arm64-print-report-from-tag-fault-handler
+++ a/arch/arm64/mm/fault.c
@@ -15,6 +15,7 @@
#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>
@@ -298,10 +299,23 @@ static void die_kernel_fault(const char
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)
--- a/mm/kasan/report.c~kasan-arm64-print-report-from-tag-fault-handler
+++ a/mm/kasan/report.c
@@ -62,9 +62,14 @@ static void print_error_description(stru
{
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);
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-drop-unnecessary-gpl-text-from-comment-headers.patch
kasan-kasan_vmalloc-depends-on-kasan_generic.patch
kasan-group-vmalloc-code.patch
s390-kasan-include-asm-pageh-from-asm-kasanh.patch
kasan-shadow-declarations-only-for-software-modes.patch
kasan-rename-unpoison_shadow-to-unpoison_memory.patch
kasan-rename-kasan_shadow_-to-kasan_granule_.patch
kasan-only-build-initc-for-software-modes.patch
kasan-split-out-shadowc-from-commonc.patch
kasan-define-kasan_granule_page.patch
kasan-rename-report-and-tags-files.patch
kasan-dont-duplicate-config-dependencies.patch
kasan-hide-invalid-free-check-implementation.patch
kasan-decode-stack-frame-only-with-kasan_stack_enable.patch
kasan-arm64-only-init-shadow-for-software-modes.patch
kasan-arm64-only-use-kasan_depth-for-software-modes.patch
kasan-arm64-move-initialization-message.patch
kasan-arm64-rename-kasan_init_tags-and-mark-as-__init.patch
kasan-rename-addr_has_shadow-to-addr_has_metadata.patch
kasan-rename-print_shadow_for_address-to-print_memory_metadata.patch
kasan-kasan_non_canonical_hook-only-for-software-modes.patch
kasan-rename-shadow-layout-macros-to-meta.patch
kasan-separate-metadata_fetch_row-for-each-mode.patch
kasan-arm64-dont-allow-sw_tags-with-arm64_mte.patch
kasan-introduce-config_kasan_hw_tags.patch
arm64-kasan-align-allocations-for-hw_tags.patch
arm64-kasan-add-arch-layer-for-memory-tagging-helpers.patch
kasan-define-kasan_granule_size-for-hw_tags.patch
kasan-x86-s390-update-undef-config_kasan.patch
kasan-arm64-expand-config_kasan-checks.patch
kasan-arm64-implement-hw_tags-runtime.patch
kasan-arm64-print-report-from-tag-fault-handler.patch
kasan-mm-reset-tags-when-accessing-metadata.patch
kasan-arm64-enable-config_kasan_hw_tags.patch
kasan-add-documentation-for-hardware-tag-based-mode.patch
