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authorMarco Elver <[email protected]>2020-05-22 22:22:59 -0700
committerLinus Torvalds <[email protected]>2020-05-23 10:26:31 -0700
commit33cd65e73abd693c00c4156cf23677c453b41b3b (patch)
treecf1237060c2eb28ccf1a3916d1bf0aea5fdb6654
parent380e5c1d9b5e9768315eb4d405c127cb655406b3 (diff)
kasan: disable branch tracing for core runtime
During early boot, while KASAN is not yet initialized, it is possible to enter reporting code-path and end up in kasan_report(). While uninitialized, the branch there prevents generating any reports, however, under certain circumstances when branches are being traced (TRACE_BRANCH_PROFILING), we may recurse deep enough to cause kernel reboots without warning. To prevent similar issues in future, we should disable branch tracing for the core runtime. [[email protected]: remove duplicate DISABLE_BRANCH_PROFILING, per Qian Cai] Link: https://lore.kernel.org/lkml/20200517011732.GE24705@shao2-debian/ Link: http://lkml.kernel.org/r/[email protected] Reported-by: kernel test robot <[email protected]> Signed-off-by: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Reviewed-by: Andrey Konovalov <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Qian Cai <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r//20200517011732.GE24705@shao2-debian/ Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
-rw-r--r--mm/kasan/Makefile16
-rw-r--r--mm/kasan/generic.c1
-rw-r--r--mm/kasan/tags.c1
3 files changed, 8 insertions, 10 deletions
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index 434d503a6525..de3121848ddf 100644
--- a/mm/kasan/Makefile
+++ b/mm/kasan/Makefile
@@ -15,14 +15,14 @@ CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS_FTRACE)
# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
-CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_init.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_quarantine.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
-CFLAGS_tags_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_init.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_quarantine.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
+CFLAGS_tags_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -DDISABLE_BRANCH_PROFILING
obj-$(CONFIG_KASAN) := common.o init.o report.o
obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 56ff8885fe2e..098a7dbaced6 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -15,7 +15,6 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#define DISABLE_BRANCH_PROFILING
#include <linux/export.h>
#include <linux/interrupt.h>
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index 25b7734e7013..8a959fdd30e3 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -12,7 +12,6 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#define DISABLE_BRANCH_PROFILING
#include <linux/export.h>
#include <linux/interrupt.h>