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authorDave Martin <Dave.Martin@arm.com>2018-03-01 17:44:06 +0000
committerEric W. Biederman <ebiederm@xmission.com>2018-03-15 16:04:25 -0500
commit266da65e9156d93e1126e185259a4aae68188d0e (patch)
tree0591d9cd021e9693a5bbf56e914ea140ea2be091
parentf6a015498dcaee72f80283cb7873d88deb07129c (diff)
downloadlinux-266da65e9156d93e1126e185259a4aae68188d0e.tar.gz
signal: Add FPE_FLTUNK si_code for undiagnosable fp exceptions
Some architectures cannot always report accurately what kind of
floating-point exception triggered a floating-point exception trap.

This can occur with fp exceptions occurring on lanes in a vector
instruction on arm64 for example.

Rather than have every architecture come up with its own way of
describing such a condition, this patch adds a common FPE_FLTUNK
si_code value to report that an fp exception caused a trap but we
cannot be certain which kind of fp exception it was.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
-rw-r--r--arch/x86/kernel/signal_compat.c2
-rw-r--r--include/uapi/asm-generic/siginfo.h3
2 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index 0d930d8987cc..d2884e951bb5 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)
 	 * new fields are handled in copy_siginfo_to_user32()!
 	 */
 	BUILD_BUG_ON(NSIGILL  != 11);
-	BUILD_BUG_ON(NSIGFPE  != 13);
+	BUILD_BUG_ON(NSIGFPE  != 14);
 	BUILD_BUG_ON(NSIGSEGV != 4);
 	BUILD_BUG_ON(NSIGBUS  != 5);
 	BUILD_BUG_ON(NSIGTRAP != 4);
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 99c902e460c2..4b3520bf67ba 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -229,7 +229,8 @@ typedef struct siginfo {
 # define __FPE_INVASC	12	/* invalid ASCII digit */
 # define __FPE_INVDEC	13	/* invalid decimal digit */
 #endif
-#define NSIGFPE		13
+#define FPE_FLTUNK	14	/* undiagnosed floating-point exception */
+#define NSIGFPE		14
 
 /*
  * SIGSEGV si_codes