[PATCH] selftests/powerpc: Fix build failures with GCC 9

[PATCH] selftests/powerpc: Fix build failures with GCC 9

[Michael Ellerman]

GCC 9 fails to build some of the ptrace TM tests, with errors such as:

  ptrace-tm-spd-vsx.c: In function 'tm_spd_vsx':
  ptrace-tm-spd-vsx.c:51:2: error: listing the stack pointer register 'r1' in a clobber list is deprecated [-Werror=deprecated]
     51 |  asm __volatile__(
        |  ^~~
  ptrace-tm-spd-vsx.c:51:2: note: the value of the stack pointer after an 'asm' statement must be the same as it was before the statement

Which is probably fair enough.

Some of these inline asm blocks are doing quite a lot and are probably
pushing the boundaries of what's sane to do with inline asm, but they
shouldn't actually be returning with r1 modified.

So drop r1 from the clobbers for now, we should probably rewrite them
to be real asm functions at some point.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c | 3 +--
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c     | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c     | 3 +--
 4 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c
index 25e23e73c72e..7b835ef4f8a6 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c
@@ -73,7 +73,7 @@ void tm_spd_tar(void)
 		[sprn_texasr]"i"(SPRN_TEXASR), [tar_1]"i"(TAR_1),
 		[dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2), [dscr_2]"i"(DSCR_2),
 		[tar_3]"i"(TAR_3), [dscr_3]"i"(DSCR_3)
-		: "memory", "r0", "r1", "r3", "r4", "r5", "r6"
+		: "memory", "r0", "r3", "r4", "r5", "r6"
 		);
 
 	/* TM failed, analyse */
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 f603fe5a445b..724e5aa499cd 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
@@ -74,8 +74,7 @@ void tm_spd_vsx(void)
 		"3: ;"
 		: [res] "=r" (result), [texasr] "=r" (texasr)
 		: [sprn_texasr] "i"  (SPRN_TEXASR)
-		: "memory", "r0", "r1", "r3", "r4",
-		"r7", "r8", "r9", "r10", "r11"
+		: "memory", "r0", "r3", "r4", "r7", "r8", "r9", "r10", "r11"
 		);
 
 	if (result) {
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c
index e0d37f07bdeb..46ef378a15ec 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c
@@ -62,7 +62,7 @@ void tm_tar(void)
 		[sprn_ppr]"i"(SPRN_PPR), [sprn_texasr]"i"(SPRN_TEXASR),
 		[tar_1]"i"(TAR_1), [dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2),
 		[dscr_2]"i"(DSCR_2), [cptr1] "b" (&cptr[1])
-		: "memory", "r0", "r1", "r3", "r4", "r5", "r6"
+		: "memory", "r0", "r3", "r4", "r5", "r6"
 		);
 
 	/* TM failed, analyse */
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
index 8027457b97b7..9f16f3a74e28 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
@@ -62,8 +62,7 @@ void tm_vsx(void)
 		"3: ;"
 		: [res] "=r" (result), [texasr] "=r" (texasr)
 		: [sprn_texasr] "i"  (SPRN_TEXASR), [cptr1] "b" (&cptr[1])
-		: "memory", "r0", "r1", "r3", "r4",
-		"r7", "r8", "r9", "r10", "r11"
+		: "memory", "r0", "r3", "r4", "r7", "r8", "r9", "r10", "r11"
 		);
 
 	if (result) {
-- 
2.21.0

Re: [PATCH] selftests/powerpc: Fix build failures with GCC 9

[Segher Boessenkool]

On Thu, Aug 01, 2019 at 10:26:28PM +1000, Michael Ellerman wrote:
> GCC 9 fails to build some of the ptrace TM tests, with errors such as:
> 
>   ptrace-tm-spd-vsx.c: In function 'tm_spd_vsx':
>   ptrace-tm-spd-vsx.c:51:2: error: listing the stack pointer register 'r1' in a clobber list is deprecated [-Werror=deprecated]
>      51 |  asm __volatile__(
>         |  ^~~
>   ptrace-tm-spd-vsx.c:51:2: note: the value of the stack pointer after an 'asm' statement must be the same as it was before the statement
> 
> Which is probably fair enough.

Maybe you shouldn't build the tests with -Werror though?  (And you could
include the much more useful -Wextra while you're at it ;-) ).

> Some of these inline asm blocks are doing quite a lot and are probably
> pushing the boundaries of what's sane to do with inline asm,

These are just testcases, you sometimes need to do evil things there.
But yeah :-)

> but they shouldn't actually be returning with r1 modified.

But they *do* modify lr, and that one isnt't listed; I guess the r1
clobber was there because of the call in the asm, but that needs an
lr clobber, instead.

(Or it was because of the "or 1,1,1")?


Segher