linux-stable.git/tools/testing/selftests/powerpc, branch linux-6.6.y

selftests/powerpc: Suppress -Wmaybe-uninitialized with GCC 15

2026-05-23T11:03:07+00:00

[ Upstream commit 6e65886fceb23605eff952d6b1975737b4c4b154 ]

GCC 15 reports the below false positive '-Wmaybe-uninitialized' warning
in vphn_unpack_associativity() when building the powerpc selftests.

  # make -C tools/testing/selftests TARGETS="powerpc"
  [...]
    CC       test-vphn
  In file included from test-vphn.c:3:
  In function ‘vphn_unpack_associativity’,
      inlined from ‘test_one’ at test-vphn.c:371:2,
      inlined from ‘test_vphn’ at test-vphn.c:399:9:
  test-vphn.c:10:33: error: ‘be_packed’ may be used uninitialized [-Werror=maybe-uninitialized]
     10 | #define be16_to_cpup(x)         bswap_16(*x)
        |                                 ^~~~~~~~
  vphn.c:42:27: note: in expansion of macro ‘be16_to_cpup’
     42 |                 u16 new = be16_to_cpup(field++);
        |                           ^~~~~~~~~~~~
  In file included from test-vphn.c:19:
  vphn.c: In function ‘test_vphn’:
  vphn.c:27:16: note: ‘be_packed’ declared here
     27 |         __be64 be_packed[VPHN_REGISTER_COUNT];
        |                ^~~~~~~~~
  cc1: all warnings being treated as errors

When vphn_unpack_associativity() is called from hcall_vphn() in kernel
the error is not seen while building vphn.c during kernel compilation.
This is because the top level Makefile includes '-fno-strict-aliasing'
flag always.

The issue here is that GCC 15 emits '-Wmaybe-uninitialized' due to type
punning between __be64[] and __b16* when accessing the buffer via
be16_to_cpup(). The underlying object is fully initialized but GCC 15
fails to track the aliasing due to the strict aliasing violation here.
Please refer [1] and [2]. This results in a false positive warning which
is promoted to an error under '-Werror'. This problem is not seen when
the compilation is performed with GCC 13 and 14. An issue [1] has also
been created on GCC bugzilla.

The selftest compiles fine with '-fno-strict-aliasing'. Since this GCC
flag is used to compile vphn.c in kernel too, the same flag should be
used to build vphn tests when compiling vphn.c in the selftest as well.

Fix this by including '-fno-strict-aliasing' during vphn.c compilation
in the selftest. This keeps the build working while limiting the scope
of the suppression to building vphn tests.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124427
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99768

Fixes: 58dae82843f5 ("selftests/powerpc: Add test for VPHN")
Reviewed-by: Vaibhav Jain 
Signed-off-by: Amit Machhiwal 
Tested-by: Venkat Rao Bagalkote 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/20260313165426.43259-1-amachhiw@linux.ibm.com
Signed-off-by: Sasha Levin

selftests/powerpc: Re-order *FLAGS to follow lib.mk

2026-05-23T11:03:07+00:00

[ Upstream commit 37496845c812db2a470d51088a59ee38156e8058 ]

In some powerpc/ sub-folder Makefiles, CFLAGS are defined before lib.mk
include. Clean it up by re-ordering the flags to follow after the mk
include. This is needed to support sub-folders in powerpc/ buildable on
its own.

Signed-off-by: Madhavan Srinivasan 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240229093711.581230-1-maddy@linux.ibm.com
Stable-dep-of: 6e65886fceb2 ("selftests/powerpc: Suppress -Wmaybe-uninitialized with GCC 15")
Signed-off-by: Sasha Levin

selftests/powerpc: Fix argument order to timer_sub()

2025-02-08T08:51:43+00:00

[ Upstream commit 2bf66e66d2e6feece6175ec09ec590a0a8563bdd ]

Commit c814bf958926 ("powerpc/selftests: Use timersub() for
gettimeofday()"), got the order of arguments to timersub() wrong,
leading to a negative time delta being reported, eg:

  test: gettimeofday
  tags: git_version:v6.12-rc5-409-gdddf291c3030
  time = -3.297781
  success: gettimeofday

The correct order is minuend, subtrahend, which in this case is end,
start. Which gives:

  test: gettimeofday
  tags: git_version:v6.12-rc5-409-gdddf291c3030-dirty
  time = 3.300650
  success: gettimeofday

Fixes: c814bf958926 ("powerpc/selftests: Use timersub() for gettimeofday()")
Signed-off-by: Michael Ellerman 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/20241218114347.428108-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin

selftests/powerpc/dexcr: Add -no-pie to hashchk tests

2024-06-12T09:12:44+00:00

[ Upstream commit d7228a58d9438d6f219dc7f33eab0d1980b3bd2f ]

The hashchk tests want to verify that the hash key is changed over exec.
It does so by calculating hashes at the same address across an exec.
This is made simpler by disabling PIE functionality, so we can
re-execute ourselves and be using the same addresses in the child.

While -fno-pie is already added, -no-pie is also required.

Fixes: bdb07f35a52f ("selftests/powerpc/dexcr: Add hashst/hashchk test")
Signed-off-by: Benjamin Gray 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240417112325.728010-2-bgray@linux.ibm.com
Signed-off-by: Sasha Levin

selftests/powerpc: Fix error handling in FPU/VMX preemption tests

2024-01-25T23:35:13+00:00

[ Upstream commit 9dbd5927408c4a0707de73ae9dd9306b184e8fee ]

The FPU & VMX preemption tests do not check for errors returned by the
low-level asm routines, preempt_fpu() / preempt_vsx() respectively.
That means any register corruption detected by the asm routines does not
result in a test failure.

Fix it by returning the return value of the asm routines from the
pthread child routines.

Fixes: e5ab8be68e44 ("selftests/powerpc: Test preservation of FPU and VMX regs across preemption")
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231128132748.1990179-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin

selftests/powerpc: Fix emit_tests to work with run_kselftest.sh

2023-09-22T10:29:48+00:00

In order to use run_kselftest.sh the list of tests must be emitted to
populate kselftest-list.txt.

The powerpc Makefile is written to use EMIT_TESTS. But support for
EMIT_TESTS was dropped in commit d4e59a536f50 ("selftests: Use runner.sh
for emit targets"). Although prior to that commit a548de0fe8e1
("selftests: lib.mk: add test execute bit check to EMIT_TESTS") had
already broken run_kselftest.sh for powerpc due to the executable check
using the wrong path.

It can be fixed by replacing the EMIT_TESTS definitions with actual
emit_tests rules in the powerpc Makefiles. This makes run_kselftest.sh
able to run powerpc tests:

  $ cd linux
  $ export ARCH=powerpc
  $ export CROSS_COMPILE=powerpc64le-linux-gnu-
  $ make headers
  $ make -j -C tools/testing/selftests install
  $ grep -c "^powerpc" tools/testing/selftests/kselftest_install/kselftest-list.txt
  182

Fixes: d4e59a536f50 ("selftests: Use runner.sh for emit targets")
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230921072623.828772-1-mpe@ellerman.id.au

powerpc/pseries: Move VPHN constants into vphn.h

2023-08-24T12:33:16+00:00

These don't have any particularly good reason to belong in lppaca.h,
move them into their own header.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230823055317.751786-1-mpe@ellerman.id.au

selftests/powerpc: add const qualification where possible

2023-08-18T07:03:15+00:00

Various char * parameters in the common powerpc selftest APIs can be
const.

Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230817-powerpc-selftest-misc-v1-2-a84cc1ef78b2@linux.ibm.com

powerpc/selftests: sort mm/.gitignore, add exec_prot

2023-08-18T07:03:15+00:00

Add exec_prot to to mm/.gitignore and sort the result.

Signed-off-by: Nathan Lynch 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230817-powerpc-selftest-misc-v1-1-a84cc1ef78b2@linux.ibm.com

selftests/powerpc/ptrace: Update ptrace-perf watchpoint selftest

2023-08-16T13:54:50+00:00

Now that ptrace and perf are no longer exclusive, update the
test to exercise interesting interactions.

An assembly file is used for the children to allow precise instruction
choice and addresses, while avoiding any compiler quirks.

Signed-off-by: Benjamin Gray 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20230801011744.153973-7-bgray@linux.ibm.com