[PATCH] selftests/powerpc: fix build error in powerpc ptrace selftests.

From: Simon Guo <redacted>

GCC 7 will take "r2" in clobber list as an error will it will get following
build errors for powerpc ptrace selftests even with -fno-pic option:
  ptrace-tm-vsx.c: In function ‘tm_vsx’:
  ptrace-tm-vsx.c:42:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-vsx] Error 1
  ptrace-tm-spd-vsx.c: In function ‘tm_spd_vsx’:
  ptrace-tm-spd-vsx.c:55:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-spd-vsx] Error 1
  ptrace-tm-spr.c: In function ‘tm_spr’:
  ptrace-tm-spr.c:46:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~

This patch fix the build error by removing "r2" out of clobber list.

Reported-by: Seth Forshee <redacted>
Signed-off-by: Simon Guo <redacted>
Tested-by: Seth Forshee <redacted>
---
 tools/testing/selftests/powerpc/ptrace/Makefile            | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c | 4 ++--
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c     | 3 +--
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c     | 2 +-
 4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile
index fe6bc60..c836f6d 100644
--- a/tools/testing/selftests/powerpc/ptrace/Makefile
+++ b/tools/testing/selftests/powerpc/ptrace/Makefile

@@ -6,7 +6,7 @@ include ../../lib.mk
 
 all: $(TEST_PROGS)
 
-CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm
+CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pic
 
 $(TEST_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
 

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
index 0df3c23..277dade 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c

@@ -79,8 +79,8 @@ void tm_spd_vsx(void)
 		: [res] "=r" (result), [texasr] "=r" (texasr)
 		: [fp_load] "r" (fp_load), [fp_load_ckpt] "r" (fp_load_ckpt),
 		[sprn_texasr] "i"  (SPRN_TEXASR)
-		: "memory", "r0", "r1", "r2", "r3", "r4",
-		"r8", "r9", "r10", "r11"
+		: "memory", "r0", "r1", "r3", "r4",
+		"r7", "r8", "r9", "r10", "r11"
 		);
 
 	if (result) {

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
index 94e57cb..51427a2 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c

@@ -76,8 +76,7 @@ void tm_spr(void)
 		: [tfhar] "=r" (tfhar), [res] "=r" (result),
 		[texasr] "=r" (texasr), [cptr1] "=r" (cptr1)
 		: [sprn_texasr] "i"  (SPRN_TEXASR)
-		: "memory", "r0", "r1", "r2", "r3", "r4",
-		"r8", "r9", "r10", "r11", "r31"
+		: "memory", "r0", "r8", "r31"
 		);
 
 	/* There are 2 32bit instructions before tbegin. */

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
index b4081e2..17c23ca 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c

@@ -67,7 +67,7 @@ void tm_vsx(void)
 		: [res] "=r" (result), [texasr] "=r" (texasr)
 		: [fp_load] "r" (fp_load), [fp_load_ckpt] "r" (fp_load_ckpt),
 		[sprn_texasr] "i"  (SPRN_TEXASR), [cptr1] "r" (&cptr[1])
-		: "memory", "r0", "r1", "r2", "r3", "r4",
+		: "memory", "r0", "r1", "r3", "r4",
 		"r7", "r8", "r9", "r10", "r11"
 		);
 

-- 
1.8.3.1

wei.guo.simon@gmail.com writes:

From: Simon Guo <redacted>

GCC 7 will take "r2" in clobber list as an error will it will get followi=

ng

build errors for powerpc ptrace selftests even with -fno-pic option:
  ptrace-tm-vsx.c: In function =E2=80=98tm_vsx=E2=80=99:
  ptrace-tm-vsx.c:42:2: error: PIC register clobbered by =E2=80=98r2=E2=

=80=99 in =E2=80=98asm=E2=80=99

    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-vsx] Error 1
  ptrace-tm-spd-vsx.c: In function =E2=80=98tm_spd_vsx=E2=80=99:
  ptrace-tm-spd-vsx.c:55:2: error: PIC register clobbered by =E2=80=98r2=

=E2=80=99 in =E2=80=98asm=E2=80=99

    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-spd-vsx] Error 1
  ptrace-tm-spr.c: In function =E2=80=98tm_spr=E2=80=99:
  ptrace-tm-spr.c:46:2: error: PIC register clobbered by =E2=80=98r2=E2=

=80=99 in =E2=80=98asm=E2=80=99

    asm __volatile__(
    ^~~

This patch fix the build error by removing "r2" out of clobber list.

But do any of the blocks clobber r2? If so then it should be in the
clobber list.

cheers

Hi Michael,
On Tue, Oct 10, 2017 at 09:10:32PM +1100, Michael Ellerman wrote:

wei.guo.simon@gmail.com writes:

quoted

From: Simon Guo <redacted>

GCC 7 will take "r2" in clobber list as an error will it will get following
build errors for powerpc ptrace selftests even with -fno-pic option:
  ptrace-tm-vsx.c: In function ‘tm_vsx’:
  ptrace-tm-vsx.c:42:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-vsx] Error 1
  ptrace-tm-spd-vsx.c: In function ‘tm_spd_vsx’:
  ptrace-tm-spd-vsx.c:55:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-spd-vsx] Error 1
  ptrace-tm-spr.c: In function ‘tm_spr’:
  ptrace-tm-spr.c:46:2: error: PIC register clobbered by ‘r2’ in ‘asm’
    asm __volatile__(
    ^~~

This patch fix the build error by removing "r2" out of clobber list.

But do any of the blocks clobber r2? If so then it should be in the
clobber list.

I see none of them clobbers r2, and neither does those assembly
functions which those blocks calls, like "loadvsx".

For the change on tools/testing/selftests/powerpc/ptrace/Makefile, it
can be ignored since I noticed recent commit a3c01050584da3 "selftests/powerpc: 
Force ptrace tests to build -fno-pie". Please let me know if you want
a new v2 to remove that change on ptrace/Makefile.

Thanks,
- Simon

On Fri, 2017-09-01 at 02:17:14 UTC, wei.guo.simon@gmail.com wrote:

From: Simon Guo <redacted>

GCC 7 will take "r2" in clobber list as an error will it will get following
build errors for powerpc ptrace selftests even with -fno-pic option:
  ptrace-tm-vsx.c: In function ���tm_vsx���:
  ptrace-tm-vsx.c:42:2: error: PIC register clobbered by ���r2��� in ���asm���
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-vsx] Error 1
  ptrace-tm-spd-vsx.c: In function ���tm_spd_vsx���:
  ptrace-tm-spd-vsx.c:55:2: error: PIC register clobbered by ���r2��� in ���asm���
    asm __volatile__(
    ^~~
  make[1]: *** [ptrace-tm-spd-vsx] Error 1
  ptrace-tm-spr.c: In function ���tm_spr���:
  ptrace-tm-spr.c:46:2: error: PIC register clobbered by ���r2��� in ���asm���
    asm __volatile__(
    ^~~

This patch fix the build error by removing "r2" out of clobber list.

Reported-by: Seth Forshee <redacted>
Signed-off-by: Simon Guo <redacted>
Tested-by: Seth Forshee <redacted>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/f36dbfe1a504b85c7b3bf89fdd9999

cheers