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authorMark Brown <broonie@kernel.org>2021-09-13 13:55:01 +0100
committerWill Deacon <will@kernel.org>2021-09-29 14:40:32 +0100
commit736e6d5a54511e1438cb81d38e5d9f164eb2af1a (patch)
treef2adb51133dc434238af3d5cf4d87ffc7be9a626 /tools/testing/selftests/arm64
parentselftests: arm64: Remove extraneous register setting code (diff)
downloadlinux-dev-736e6d5a54511e1438cb81d38e5d9f164eb2af1a.tar.xz
linux-dev-736e6d5a54511e1438cb81d38e5d9f164eb2af1a.zip
selftests: arm64: Document what the SVE ptrace test is doing
Before we go modifying it further let's add some comments and output clarifications explaining what this test is actually doing. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210913125505.52619-5-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'tools/testing/selftests/arm64')
-rw-r--r--tools/testing/selftests/arm64/fp/sve-ptrace.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
index d2ec48f649f9..fc4a672825eb 100644
--- a/tools/testing/selftests/arm64/fp/sve-ptrace.c
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c
@@ -181,6 +181,7 @@ static int do_parent(pid_t child)
}
}
+ /* New process should start with FPSIMD registers only */
sve = get_sve(pid, &svebuf, &svebufsz);
if (!sve) {
int e = errno;
@@ -191,14 +192,15 @@ static int do_parent(pid_t child)
goto error;
} else {
- ksft_test_result_pass("get_sve\n");
+ ksft_test_result_pass("get_sve(FPSIMD)\n");
}
ksft_test_result((sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD,
- "FPSIMD registers\n");
+ "Set FPSIMD registers\n");
if ((sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_FPSIMD)
goto error;
+ /* Try to set a known FPSIMD state via PT_REGS_SVE */
fpsimd = (struct user_fpsimd_state *)((char *)sve +
SVE_PT_FPSIMD_OFFSET);
for (i = 0; i < 32; ++i) {
@@ -219,6 +221,7 @@ static int do_parent(pid_t child)
goto error;
}
+ /* Zero the first SVE Z register */
vq = sve_vq_from_vl(sve->vl);
newsvebufsz = SVE_PT_SVE_ZREG_OFFSET(vq, 1);
@@ -245,6 +248,7 @@ static int do_parent(pid_t child)
goto error;
}
+ /* Try to read back the value we just set */
new_sve = get_sve(pid, &newsvebuf, &newsvebufsz);
if (!new_sve) {
int e = errno;
@@ -257,12 +261,13 @@ static int do_parent(pid_t child)
}
ksft_test_result((new_sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_SVE,
- "SVE registers\n");
+ "Get SVE registers\n");
if ((new_sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_SVE)
goto error;
dump_sve_regs(new_sve, 3, sizeof fpsimd->vregs[0]);
+ /* Verify that the register we set has the value we expected */
p = (unsigned char *)new_sve + SVE_PT_SVE_ZREG_OFFSET(vq, 1);
for (i = 0; i < sizeof fpsimd->vregs[0]; ++i) {
unsigned char expected = i;