summaryrefslogtreecommitdiff
path: root/arch/arm/kernel/signal.c
diff options
context:
space:
mode:
authorThomas Garnier <thgarnie@google.com>2017-09-07 08:30:46 -0700
committerThomas Gleixner <tglx@linutronix.de>2017-09-17 19:45:33 +0200
commite33f8d32677fa4f4f8996ef46748f86aac81ccff (patch)
tree152d8320692675e6c04e141d61557114839baf71 /arch/arm/kernel/signal.c
parent2404269bc4e77a67875c8db6667be34c9913c96e (diff)
arm/syscalls: Optimize address limit check
Disable the generic address limit check in favor of an architecture specific optimized implementation. The generic implementation using pending work flags did not work well with ARM and alignment faults. The address limit is checked on each syscall return path to user-mode path as well as the irq user-mode return function. If the address limit was changed, a function is called to report data corruption (stopping the kernel or process based on configuration). The address limit check has to be done before any pending work because they can reset the address limit and the process is killed using a SIGKILL signal. For example the lkdtm address limit check does not work because the signal to kill the process will reset the user-mode address limit. Signed-off-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Leonard Crestez <leonard.crestez@nxp.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Pratyush Anand <panand@redhat.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Will Drewry <wad@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Andy Lutomirski <luto@amacapital.net> Cc: David Howells <dhowells@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-api@vger.kernel.org Cc: Yonghong Song <yhs@fb.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1504798247-48833-4-git-send-email-keescook@chromium.org
Diffstat (limited to 'arch/arm/kernel/signal.c')
-rw-r--r--arch/arm/kernel/signal.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 5814298ef0b7..b67ae12503f3 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -14,6 +14,7 @@
#include <linux/uaccess.h>
#include <linux/tracehook.h>
#include <linux/uprobes.h>
+#include <linux/syscalls.h>
#include <asm/elf.h>
#include <asm/cacheflush.h>
@@ -673,3 +674,9 @@ struct page *get_signal_page(void)
return page;
}
+
+/* Defer to generic check */
+asmlinkage void addr_limit_check_failed(void)
+{
+ addr_limit_user_check();
+}