mpx: Extend siginfo structure to include bound violation information

This patch adds new fields about bound violation into siginfo
structure. si_lower and si_upper are respectively lower bound
and upper bound when bound violation is caused.

Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Cc: linux-mips@linux-mips.org
Cc: Dave Hansen <dave@sr71.net>
Link: http://lkml.kernel.org/r/20141114151819.1908C900@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 12 insertions, 1 deletions

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index ba5be7fdbdfe..1e3552037a5a 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -91,6 +91,10 @@ typedef struct siginfo {
                         int _trapno;    /* TRAP # which caused the signal */
 #endif
                         short _addr_lsb; /* LSB of the reported address */
+                        struct {
+                                void __user *_lower;
+                                void __user *_upper;
+                        } _addr_bnd;
                 } _sigfault;
 
                 /* SIGPOLL */
@@ -131,6 +135,8 @@ typedef struct siginfo {
 #define si_trapno       _sifields._sigfault._trapno
 #endif
 #define si_addr_lsb     _sifields._sigfault._addr_lsb
+#define si_lower        _sifields._sigfault._addr_bnd._lower
+#define si_upper        _sifields._sigfault._addr_bnd._upper
 #define si_band         _sifields._sigpoll._band
 #define si_fd           _sifields._sigpoll._fd
 #ifdef __ARCH_SIGSYS
@@ -199,7 +205,8 @@ typedef struct siginfo {
  */
 #define SEGV_MAPERR     (__SI_FAULT|1)  /* address not mapped to object */
 #define SEGV_ACCERR     (__SI_FAULT|2)  /* invalid permissions for mapped object */
-#define NSIGSEGV        2
+#define SEGV_BNDERR     (__SI_FAULT|3)  /* failed address bound checks */
+#define NSIGSEGV        3
 
 /*
  * SIGBUS si_codes
diff --git a/kernel/signal.c b/kernel/signal.c
index 8f0876f9f6dd..2c403a4c8bee 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2748,6 +2748,10 @@ int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
                 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
                         err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
 #endif
+#ifdef SEGV_BNDERR
+                err |= __put_user(from->si_lower, &to->si_lower);
+                err |= __put_user(from->si_upper, &to->si_upper);
+#endif
                 break;
         case __SI_CHLD:
                 err |= __put_user(from->si_pid, &to->si_pid);