[PATCH V3] powerpc: add little endian flag to syscall_get_arch()

[Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Since both ppc and ppc64 have LE variants which are now reported by uname, add
that flag (__AUDIT_ARCH_LE) to syscall_get_arch() and add AUDIT_ARCH_PPC*LE
variants.

Without this,  perf trace and auditctl fail.

Mainline kernel reports ppc64le (per a058801) but there is no matching
AUDIT_ARCH_PPC64LE.

Since 32-bit PPC LE is not supported, throw a compiler error rather than return
a bogus architecture to audit.

See:
	https://www.redhat.com/archives/linux-audit/2014-August/msg00082.html
	https://www.redhat.com/archives/linux-audit/2014-December/msg00004.html

v2 -> v3:
	Throw a compiler error on 32-bit LE.

v1 -> v2:
	Added ";" at the end of the #ifdef-protected line so it actually compiles

Signed-off-by: Richard Guy Briggs <rgb-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/powerpc/include/asm/syscall.h |    7 +++++++
 include/uapi/linux/audit.h         |    1 +
 2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index 6fa2708..cf7fcab 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -90,6 +90,13 @@ static inline void syscall_set_arguments(struct task_struct *task,
 
 static inline int syscall_get_arch(void)
 {
+#ifdef __LITTLE_ENDIAN__
+	return AUDIT_ARCH_PPC64LE;
+#ifndef CONFIG_64BIT
+#error PPC 32-bit Little Endian architecture not supported.
+#endif /* CONFIG_64BIT */
+#else /* __LITTLE_ENDIAN__ */
 	return is_32bit_task() ? AUDIT_ARCH_PPC : AUDIT_ARCH_PPC64;
+#endif /* __LITTLE_ENDIAN__ */
 }
 #endif	/* _ASM_SYSCALL_H */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 4d100c8..fa2a6af 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -365,6 +365,7 @@ enum {
 #define AUDIT_ARCH_PARISC64	(EM_PARISC|__AUDIT_ARCH_64BIT)
 #define AUDIT_ARCH_PPC		(EM_PPC)
 #define AUDIT_ARCH_PPC64	(EM_PPC64|__AUDIT_ARCH_64BIT)
+#define AUDIT_ARCH_PPC64LE	(EM_PPC64|__AUDIT_ARCH_64BIT|__AUDIT_ARCH_LE)
 #define AUDIT_ARCH_S390		(EM_S390)
 #define AUDIT_ARCH_S390X	(EM_S390|__AUDIT_ARCH_64BIT)
 #define AUDIT_ARCH_SH		(EM_SH)
-- 
1.7.1