[PATCH v4] ARM: signal: fix armv7-m build issue in sigreturn_codes.S
Victor Kamensky
victor.kamensky at linaro.org
Wed Nov 20 02:21:12 EST 2013
After "ARM: signal: sigreturn_codes should be endian neutral to
work in BE8" commit, thumb only platforms, like armv7m, fails to
compile sigreturn_codes.S. The reason is that for such arch
values '.arm' directive and arm opcodes are not allowed.
Fix conditionally enables arm opcodes only if no CONFIG_CPU_THUMBONLY
defined and it uses .org instructions to keep sigreturn_codes
layout.
Suggested-by: Dave Martin <Dave.Martin at arm.com>
Signed-off-by: Victor Kamensky <victor.kamensky at linaro.org>
Tested-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
arch/arm/kernel/sigreturn_codes.S | 40 ++++++++++++++++++++++++++++++---------
1 file changed, 31 insertions(+), 9 deletions(-)
diff --git a/arch/arm/kernel/sigreturn_codes.S b/arch/arm/kernel/sigreturn_codes.S
index 3c5d0f2..b84d0cb 100644
--- a/arch/arm/kernel/sigreturn_codes.S
+++ b/arch/arm/kernel/sigreturn_codes.S
@@ -30,6 +30,27 @@
* snippets.
*/
+/*
+ * In CPU_THUMBONLY case kernel arm opcodes are not allowed.
+ * Note in this case codes skips those instructions but it uses .org
+ * directive to keep correct layout of sigreturn_codes array.
+ */
+#ifndef CONFIG_CPU_THUMBONLY
+#define ARM_OK(code...) code
+#else
+#define ARM_OK(code...)
+#endif
+
+ .macro arm_slot n
+ .org sigreturn_codes + 12 * (\n)
+ARM_OK( .arm )
+ .endm
+
+ .macro thumb_slot n
+ .org sigreturn_codes + 12 * (\n) + 8
+ .thumb
+ .endm
+
#if __LINUX_ARM_ARCH__ <= 4
/*
* Note we manually set minimally required arch that supports
@@ -45,26 +66,27 @@
.global sigreturn_codes
.type sigreturn_codes, #object
- .arm
+ .align
sigreturn_codes:
/* ARM sigreturn syscall code snippet */
- mov r7, #(__NR_sigreturn - __NR_SYSCALL_BASE)
- swi #(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE)
+ arm_slot 0
+ARM_OK( mov r7, #(__NR_sigreturn - __NR_SYSCALL_BASE) )
+ARM_OK( swi #(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE) )
/* Thumb sigreturn syscall code snippet */
- .thumb
+ thumb_slot 0
movs r7, #(__NR_sigreturn - __NR_SYSCALL_BASE)
swi #0
/* ARM sigreturn_rt syscall code snippet */
- .arm
- mov r7, #(__NR_rt_sigreturn - __NR_SYSCALL_BASE)
- swi #(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE)
+ arm_slot 1
+ARM_OK( mov r7, #(__NR_rt_sigreturn - __NR_SYSCALL_BASE) )
+ARM_OK( swi #(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE) )
/* Thumb sigreturn_rt syscall code snippet */
- .thumb
+ thumb_slot 1
movs r7, #(__NR_rt_sigreturn - __NR_SYSCALL_BASE)
swi #0
@@ -74,7 +96,7 @@ sigreturn_codes:
* it is thumb case or not, so we need additional
* word after real last entry.
*/
- .arm
+ arm_slot 2
.space 4
.size sigreturn_codes, . - sigreturn_codes
--
1.8.1.4
More information about the linux-arm-kernel
mailing list