| Message ID | 1394556894-18592-4-git-send-email-tixy@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 03/11/14 12:54, Jon Medhurst wrote: > Conditionally compile kprobes test cases for ARMv5 instructions to avoid > compilation errors with ARMv4 targets like: > > /tmp/cc7Tx8ST.s:16740: Error: selected processor does not support ARM mode `clz r0,r0' > > Signed-off-by: Jon Medhurst <tixy@linaro.org> > --- > arch/arm/kernel/kprobes-test-arm.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c > index 8a7428b..f9ed7cf 100644 > --- a/arch/arm/kernel/kprobes-test-arm.c > +++ b/arch/arm/kernel/kprobes-test-arm.c > @@ -216,6 +216,7 @@ void kprobe_arm_test_cases(void) > TEST_BB_R("bx r",7,2f,"") > TEST_BF_R("bxeq r",14,2f,"") > > +#if __LINUX_ARM_ARCH__ >= 5 > TEST_R("clz r0, r",0, 0x0,"") > TEST_R("clzeq r7, r",14,0x1,"") > TEST_R("clz lr, r",7, 0xffffffff,"") > @@ -337,6 +338,7 @@ void kprobe_arm_test_cases(void) > TEST_UNSUPPORTED(".word 0xe16f02e1 @ smultt pc, r1, r2") > TEST_UNSUPPORTED(".word 0xe16002ef @ smultt r0, pc, r2") > TEST_UNSUPPORTED(".word 0xe1600fe1 @ smultt r0, r1, pc") > +#endif > > TEST_GROUP("Multiply and multiply-accumulate") > > @@ -559,6 +561,7 @@ void kprobe_arm_test_cases(void) > TEST_UNSUPPORTED("ldrsht r1, [r2], #48") > #endif > > +#if __LINUX_ARM_ARCH__ >= 5 > TEST_RPR( "strd r",0, VAL1,", [r",1, 48,", -r",2,24,"]") > TEST_RPR( "strccd r",8, VAL2,", [r",13,0, ", r",12,48,"]") > TEST_RPR( "strd r",4, VAL1,", [r",2, 24,", r",3, 48,"]!") > @@ -595,6 +598,7 @@ void kprobe_arm_test_cases(void) > TEST_UNSUPPORTED(".word 0xe1efc3d0 @ ldrd r12, [pc, #48]!") > TEST_UNSUPPORTED(".word 0xe0c9f3d0 @ ldrd pc, [r9], #48") > TEST_UNSUPPORTED(".word 0xe0c9e3d0 @ ldrd lr, [r9], #48") > +#endif > > TEST_GROUP("Miscellaneous") > > @@ -1227,7 +1231,9 @@ void kprobe_arm_test_cases(void) > TEST_COPROCESSOR( "mrc"two" 0, 0, r0, cr0, cr0, 0") > > COPROCESSOR_INSTRUCTIONS_ST_LD("","e") > +#if __LINUX_ARM_ARCH__ >= 5 > COPROCESSOR_INSTRUCTIONS_MC_MR("","e") > +#endif > TEST_UNSUPPORTED("svc 0") > TEST_UNSUPPORTED("svc 0xffffff") > > @@ -1287,7 +1293,9 @@ void kprobe_arm_test_cases(void) > TEST( "blx __dummy_thumb_subroutine_odd") > #endif /* __LINUX_ARM_ARCH__ >= 6 */ > > +#if __LINUX_ARM_ARCH__ >= 5 > COPROCESSOR_INSTRUCTIONS_ST_LD("2","f") > +#endif > #if __LINUX_ARM_ARCH__ >= 6 > COPROCESSOR_INSTRUCTIONS_MC_MR("2","f") > #endif > This looks OK to me. Feel free to add my ack. -dl
On Tue, 2014-03-25 at 14:42 +0100, Arnd Bergmann wrote: > On Tuesday 25 March 2014 09:27:29 David Long wrote: > > On 03/11/14 12:54, Jon Medhurst wrote: > > > Conditionally compile kprobes test cases for ARMv5 instructions to avoid > > > compilation errors with ARMv4 targets like: > > > > > > /tmp/cc7Tx8ST.s:16740: Error: selected processor does not support ARM mode `clz r0,r0' > > > > > > Signed-off-by: Jon Medhurst <tixy@linaro.org> > > > > This looks OK to me. Feel free to add my ack. > > Ah, I had a similar patch in my 'randconfig-fixes' series. Where's that? > I noticed three > other configurations that are broken with kprobes-test: > > - ARMv3 (enabled by ARCH_RPC) Didn't know we support < ARMv4! > - ARMv7-M (enabled by ARCH_EFM32) I guess that problem is because randconfig is enabling HAVE_KPROBES, even though it wouldn't normally be selected, because we have config ARCH_ARM select HAVE_KPROBES if !XIP_KERNEL and ARCH_EFM32 is XIP_KERNEL. I think this problem goes all the way back to the commit which added HAVE_KPROBES to all arches (3f550096dede4430f83b16457da83bf429155ac2) That replaced config KPROBES depends on ... (ARM && !XIP_KERNEL) with the current select if !XIP_KERNEL, which made it possible to enable kprobes for XIP when before we couldn't. And presumably that was for a good reason like it doesn't work on XIP? Not sure at the moment how best to fix that. (Making ARM_KPROBES_TEST depend on !XIP_KERNEL doesn't solve the underlying problem of KPROBES feature still being enabled for XIP kernels.) > - CPU_ENDIAN_BE32 (enabled by building a big-endian kernel on ARMv5 or older) > Should we treat those the same way, or just disable Kprobes for this case > if nobody cares? For CPU_ENDIAN_BE32 I have a feeling that the kprobes code wouldn't work, would have to think more about why I have that feeling. If it doesn't, we come back to the problem that arch code can't add dependencies to CONFIG_KPROBES as things stand.
On Tuesday 25 March 2014 14:54:44 Jon Medhurst wrote: > On Tue, 2014-03-25 at 14:42 +0100, Arnd Bergmann wrote: > > On Tuesday 25 March 2014 09:27:29 David Long wrote: > > > On 03/11/14 12:54, Jon Medhurst wrote: > > > > Conditionally compile kprobes test cases for ARMv5 instructions to avoid > > > > compilation errors with ARMv4 targets like: > > > > > > > > /tmp/cc7Tx8ST.s:16740: Error: selected processor does not support ARM mode `clz r0,r0' > > > > > > > > Signed-off-by: Jon Medhurst <tixy@linaro.org> > > > > > > This looks OK to me. Feel free to add my ack. > > > > Ah, I had a similar patch in my 'randconfig-fixes' series. > > Where's that? http://git.kernel.org/cgit/linux/kernel/git/arnd/playground.git/commit/?h=arm-randconfig > > I noticed three > > other configurations that are broken with kprobes-test: > > > > - ARMv3 (enabled by ARCH_RPC) > > Didn't know we support < ARMv4! We don't really (any more). RPC is a v4 CPU, but we build the kernel pretending it is v3 to work around some issue I don't remember. > > - ARMv7-M (enabled by ARCH_EFM32) > > I guess that problem is because randconfig is enabling HAVE_KPROBES, > even though it wouldn't normally be selected, because we have > > config ARCH_ARM > select HAVE_KPROBES if !XIP_KERNEL > > and ARCH_EFM32 is XIP_KERNEL. Right. EFM32 can in theory run without XIP_KERNEL, but the only board we support doesn't have enough RAM for that. > I think this problem goes all the way back to the commit which added > HAVE_KPROBES to all arches (3f550096dede4430f83b16457da83bf429155ac2) > That replaced > > config KPROBES > depends on ... (ARM && !XIP_KERNEL) > > with the current select if !XIP_KERNEL, which made it possible to enable > kprobes for XIP when before we couldn't. And presumably that was for a > good reason like it doesn't work on XIP? The text segment is very read-only in XIP_KERNEL, so anything that tries to overwrite instructions can't work. > Not sure at the moment how best to fix that. (Making ARM_KPROBES_TEST > depend on !XIP_KERNEL doesn't solve the underlying problem of KPROBES > feature still being enabled for XIP kernels.) Regardless of XIP, there is the other problem of ARMv7-M support, which in particular only has THUMB2 instructions: CC arch/arm/kernel/kprobes.o /tmp/cclbjgU2.s: Assembler messages: /tmp/cclbjgU2.s:701: Error: selected processor does not support Thumb mode `rfeia sp!' make[3]: *** [arch/arm/kernel/kprobes.o] Error 1 CC arch/arm/kernel/kprobes-thumb.o /tmp/ccwlnR1o.s: Assembler messages: /tmp/ccwlnR1o.s:315: Error: selected processor does not support requested special purpose register -- `msr cpsr_fs,r0' /tmp/ccwlnR1o.s:317: Error: selected processor does not support requested special purpose register -- `mrs r0,cpsr' /tmp/ccwlnR1o.s:673: Error: selected processor does not support requested special purpose register -- `msr cpsr_fs,r3' /tmp/ccwlnR1o.s:675: Error: selected processor does not support requested special purpose register -- `mrs r3,cpsr' /tmp/ccwlnR1o.s:919: Error: selected processor does not support requested special purpose register -- `msr cpsr_fs,r8' /tmp/ccwlnR1o.s:923: Error: selected processor does not support requested special purpose register -- `mrs r9,cpsr' /tmp/ccwlnR1o.s:960: Error: selected processor does not support requested special purpose register -- `msr cpsr_fs,r8' /tmp/ccwlnR1o.s:964: Error: selected processor does not support requested special purpose register -- `mrs r9,cpsr' make[3]: *** [arch/arm/kernel/kprobes-thumb.o] Error 1 CC arch/arm/kernel/kprobes-test.o /tmp/ccVIP6jA.s: Assembler messages: /tmp/ccVIP6jA.s:1354: Error: selected processor does not support ARM opcodes /tmp/ccVIP6jA.s:1355: Error: attempt to use an ARM instruction on a Thumb-only processor -- `orr lr,lr,#1' /tmp/ccVIP6jA.s:1356: Error: attempt to use an ARM instruction on a Thumb-only processor -- `ldr pc,1f' make[3]: *** [arch/arm/kernel/kprobes-test.o] Error 1 CC arch/arm/kernel/kprobes-test-thumb.o /tmp/ccN8WTB4.s: Assembler messages: /tmp/ccN8WTB4.s:2032: Error: selected processor does not support ARM opcodes /tmp/ccN8WTB4.s:2033: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr lr,2f+1' /tmp/ccN8WTB4.s:2034: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx lr' /tmp/ccN8WTB4.s:4183: Error: selected processor does not support ARM opcodes /tmp/ccN8WTB4.s:4184: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr lr,2f+1' /tmp/ccN8WTB4.s:4185: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx lr' /tmp/ccN8WTB4.s:4222: Error: selected processor does not support ARM opcodes /tmp/ccN8WTB4.s:4223: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr lr,2f+1' /tmp/ccN8WTB4.s:4224: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx lr' /tmp/ccN8WTB4.s:5618: Error: selected processor does not support Thumb mode `rfedb sp' /tmp/ccN8WTB4.s:5639: Error: selected processor does not support Thumb mode `rfeia sp' /tmp/ccN8WTB4.s:5660: Error: selected processor does not support Thumb mode `rfedb sp!' /tmp/ccN8WTB4.s:5681: Error: selected processor does not support Thumb mode `rfeia sp!' /tmp/ccN8WTB4.s:6489: Error: selected processor does not support ARM opcodes /tmp/ccN8WTB4.s:6490: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr lr,2f+1' /tmp/ccN8WTB4.s:6491: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx lr' /tmp/ccN8WTB4.s:6528: Error: selected processor does not support ARM opcodes /tmp/ccN8WTB4.s:6529: Error: attempt to use an ARM instruction on a Thumb-only processor -- `adr lr,2f+1' /tmp/ccN8WTB4.s:6530: Error: attempt to use an ARM instruction on a Thumb-only processor -- `bx lr' /tmp/ccN8WTB4.s:7521: Error: selected processor does not support Thumb mode `strexd r0,r1,[r2]' /tmp/ccN8WTB4.s:7584: Error: selected processor does not support Thumb mode `ldrexd r0,[r1]' /tmp/ccN8WTB4.s:15321: Error: selected processor does not support Thumb mode `pkhbt r0,r0,r1' /tmp/ccN8WTB4.s:15350: Error: selected processor does not support Thumb mode `pkhbt r14,r12,r10,lsl#2' /tmp/ccN8WTB4.s:15379: Error: selected processor does not support Thumb mode `pkhtb r0,r0,r1' /tmp/ccN8WTB4.s:15408: Error: selected processor does not support Thumb mode `pkhtb r14,r12,r10,asr#2' /tmp/ccN8WTB4.s:18355: Error: selected processor does not support Thumb mode `ssat16 r0,#12,r0' > > - CPU_ENDIAN_BE32 (enabled by building a big-endian kernel on ARMv5 or older) > > > Should we treat those the same way, or just disable Kprobes for this case > > if nobody cares? > > For CPU_ENDIAN_BE32 I have a feeling that the kprobes code wouldn't > work, would have to think more about why I have that feeling. If it > doesn't, we come back to the problem that arch code can't add > dependencies to CONFIG_KPROBES as things stand. The error message I get here is arnd@wuerfel:~/arm-soc$ make O=build/0xCD5BF01B_defconfig/ -skj40 /git/arm-soc/Makefile:629: Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: -fstack-protector-strong not supported by compiler /git/arm-soc/arch/arm/kernel/patch.c: In function '__patch_text': /git/arm-soc/arch/arm/kernel/patch.c:35:4: error: implicit declaration of function '__opcode_to_mem_thumb32' [-Werror=implicit-function-declaration] insn = __opcode_to_mem_thumb32(insn); ^ I've filed that for now in the "wontfix" category, but I though I'd bring it up anyway. Arnd
diff --git a/arch/arm/kernel/kprobes-test-arm.c b/arch/arm/kernel/kprobes-test-arm.c index 8a7428b..f9ed7cf 100644 --- a/arch/arm/kernel/kprobes-test-arm.c +++ b/arch/arm/kernel/kprobes-test-arm.c @@ -216,6 +216,7 @@ void kprobe_arm_test_cases(void) TEST_BB_R("bx r",7,2f,"") TEST_BF_R("bxeq r",14,2f,"") +#if __LINUX_ARM_ARCH__ >= 5 TEST_R("clz r0, r",0, 0x0,"") TEST_R("clzeq r7, r",14,0x1,"") TEST_R("clz lr, r",7, 0xffffffff,"") @@ -337,6 +338,7 @@ void kprobe_arm_test_cases(void) TEST_UNSUPPORTED(".word 0xe16f02e1 @ smultt pc, r1, r2") TEST_UNSUPPORTED(".word 0xe16002ef @ smultt r0, pc, r2") TEST_UNSUPPORTED(".word 0xe1600fe1 @ smultt r0, r1, pc") +#endif TEST_GROUP("Multiply and multiply-accumulate") @@ -559,6 +561,7 @@ void kprobe_arm_test_cases(void) TEST_UNSUPPORTED("ldrsht r1, [r2], #48") #endif +#if __LINUX_ARM_ARCH__ >= 5 TEST_RPR( "strd r",0, VAL1,", [r",1, 48,", -r",2,24,"]") TEST_RPR( "strccd r",8, VAL2,", [r",13,0, ", r",12,48,"]") TEST_RPR( "strd r",4, VAL1,", [r",2, 24,", r",3, 48,"]!") @@ -595,6 +598,7 @@ void kprobe_arm_test_cases(void) TEST_UNSUPPORTED(".word 0xe1efc3d0 @ ldrd r12, [pc, #48]!") TEST_UNSUPPORTED(".word 0xe0c9f3d0 @ ldrd pc, [r9], #48") TEST_UNSUPPORTED(".word 0xe0c9e3d0 @ ldrd lr, [r9], #48") +#endif TEST_GROUP("Miscellaneous") @@ -1227,7 +1231,9 @@ void kprobe_arm_test_cases(void) TEST_COPROCESSOR( "mrc"two" 0, 0, r0, cr0, cr0, 0") COPROCESSOR_INSTRUCTIONS_ST_LD("","e") +#if __LINUX_ARM_ARCH__ >= 5 COPROCESSOR_INSTRUCTIONS_MC_MR("","e") +#endif TEST_UNSUPPORTED("svc 0") TEST_UNSUPPORTED("svc 0xffffff") @@ -1287,7 +1293,9 @@ void kprobe_arm_test_cases(void) TEST( "blx __dummy_thumb_subroutine_odd") #endif /* __LINUX_ARM_ARCH__ >= 6 */ +#if __LINUX_ARM_ARCH__ >= 5 COPROCESSOR_INSTRUCTIONS_ST_LD("2","f") +#endif #if __LINUX_ARM_ARCH__ >= 6 COPROCESSOR_INSTRUCTIONS_MC_MR("2","f") #endif
Conditionally compile kprobes test cases for ARMv5 instructions to avoid compilation errors with ARMv4 targets like: /tmp/cc7Tx8ST.s:16740: Error: selected processor does not support ARM mode `clz r0,r0' Signed-off-by: Jon Medhurst <tixy@linaro.org> --- arch/arm/kernel/kprobes-test-arm.c | 8 ++++++++ 1 file changed, 8 insertions(+)