[PATCH v4 1/4] signals, sparc: Add signal codes for ADI violations

From: Khalid Aziz
Date: Wed Jan 11 2017 - 11:14:47 EST


SPARC M7 processor introduces a new feature - Application Data
Integrity (ADI). ADI allows MMU to catch rogue accesses to memory.
When a rogue access occurs, MMU blocks the access and raises an
exception. In response to the exception, kernel sends the offending
task a SIGSEGV with si_code that indicates the nature of exception.
This patch adds three new signal codes specific to ADI feature:

1. ADI is not enabled for the address and task attempted to access
memory using ADI
2. Task attempted to access memory using wrong ADI tag and caused
a deferred exception.
3. Task attempted to access memory using wrong ADI Ttag and caused
a precise exception.

Signed-off-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
Cc: Khalid Aziz <khalid@xxxxxxxxxxxxxx>
---
arch/x86/kernel/signal_compat.c | 2 +-
include/uapi/asm-generic/siginfo.h | 5 ++++-
2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index ec1f756..d1e860c 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -26,7 +26,7 @@ static inline void signal_compat_build_tests(void)
*/
BUILD_BUG_ON(NSIGILL != 8);
BUILD_BUG_ON(NSIGFPE != 8);
- BUILD_BUG_ON(NSIGSEGV != 4);
+ BUILD_BUG_ON(NSIGSEGV != 7);
BUILD_BUG_ON(NSIGBUS != 5);
BUILD_BUG_ON(NSIGTRAP != 4);
BUILD_BUG_ON(NSIGCHLD != 6);
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 1abaf62..2446864 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -213,7 +213,10 @@ typedef struct siginfo {
#define SEGV_ACCERR (__SI_FAULT|2) /* invalid permissions for mapped object */
#define SEGV_BNDERR (__SI_FAULT|3) /* failed address bound checks */
#define SEGV_PKUERR (__SI_FAULT|4) /* failed protection key checks */
-#define NSIGSEGV 4
+#define SEGV_ACCADI (__SI_FAULT|5) /* ADI not enabled for mapped object */
+#define SEGV_ADIDERR (__SI_FAULT|6) /* Disrupting MCD error */
+#define SEGV_ADIPERR (__SI_FAULT|7) /* Precise MCD exception */
+#define NSIGSEGV 7

/*
* SIGBUS si_codes
--
2.7.4