Hi,
Here is version 4 of fix to armv7-m build failure in sigreturn_codes.S. The difference with version 3 is fixed formating and renamed internally used macro as per Dave's comments on [3].
Solution is based on .org directive Dave's suggestion on last email in [1].
It uses conditional compilation and it uses .org directive to keep sigreturn_codes layout.
Note I did not use ARM and THUMB macros because those switch between CONFIG_THUMB2_KERNEL and not. On v7a kernel we need both arm and thumb snipets regardless of CONFIG_THUMB2_KERNEL setting. And conditional compilation only kicks in with CONFIG_CPU_THUMBONLY, for that local ARM_INSTR macro is created.
Version 3 [3] conditional compilation and .org directive. Pretty much the same code but incorrectly formated. Please look at [3] for details.
Version 2 [2] tried to use '.acrh armv4t' directive to allow both arm and thumb2 opcodes, but solution deemed to be too fragile.
Version 1 [1] used conditional compilation and added thumb2 nop instructions in CONFIG_CPU_THUMBONLY
Fix was tested linux-next with efm32_defconfig build (along with few other fixes) rmk-next BE/LE vexpress build/boot and LTP rt_sigaction0? tests run Uwe tested version 1 and 3 with efm32
Thanks, Victor
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/210393.h... [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/210949.h... [3] http://lists.infradead.org/pipermail/linux-arm-kernel/2013-November/212307.h...
Victor Kamensky (1): ARM: signal: fix armv7-m build issue in sigreturn_codes.S
arch/arm/kernel/sigreturn_codes.S | 40 ++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-)
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@arm.com Signed-off-by: Victor Kamensky victor.kamensky@linaro.org Tested-by: Uwe Kleine-König u.kleine-koenig@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
On Tue, Nov 19, 2013 at 11:21:12PM -0800, Victor Kamensky wrote:
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@arm.com Signed-off-by: Victor Kamensky victor.kamensky@linaro.org Tested-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de
I believe this looks correct now:
Reviewed-by: Dave Martin Dave.Martin@arm.com
Cheers ---Dave
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
linaro-kernel mailing list linaro-kernel@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-kernel
On 20 November 2013 03:21, Dave Martin Dave.Martin@arm.com wrote:
On Tue, Nov 19, 2013 at 11:21:12PM -0800, Victor Kamensky wrote:
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@arm.com Signed-off-by: Victor Kamensky victor.kamensky@linaro.org Tested-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de
I believe this looks correct now:
Reviewed-by: Dave Martin Dave.Martin@arm.com
It is posted to Russell's patch system now.
Dave, thank you very much for help and guidance. Uwe, thank you for reporting, testing.
Thanks, Victor
Cheers ---Dave
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
.alignsigreturn_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 */
.armmov 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
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Victor Kamensky