| Message ID | 20231128132748.1990179-5-mpe@ellerman.id.au (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1bdf22580b794a498b17617bcd7ae417d6b78444 |
| Headers | show |
| Series | [1/5] selftests/powerpc: Fix error handling in FPU/VMX preemption tests | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 23 jobs. |
diff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testing/selftests/powerpc/math/fpu_asm.S index 051392ad3ce7..efe1e1be4695 100644 --- a/tools/testing/selftests/powerpc/math/fpu_asm.S +++ b/tools/testing/selftests/powerpc/math/fpu_asm.S @@ -109,8 +109,9 @@ FUNC_START(test_fpu) std r3,STACK_FRAME_PARAM(0)(sp) # Address of darray std r4,STACK_FRAME_PARAM(1)(sp) # Address of pid - bl load_fpu - nop + // Load FPRs with expected values + OP_REGS lfd, 8, 0, 31, r3 + li r0,__NR_fork sc @@ -119,7 +120,7 @@ FUNC_START(test_fpu) std r3,0(r9) ld r3,STACK_FRAME_PARAM(0)(sp) - bl check_fpu + bl check_all_fprs nop POP_FPU(256) diff --git a/tools/testing/selftests/powerpc/math/fpu_syscall.c b/tools/testing/selftests/powerpc/math/fpu_syscall.c index 694f225c7e45..751d46b133fc 100644 --- a/tools/testing/selftests/powerpc/math/fpu_syscall.c +++ b/tools/testing/selftests/powerpc/math/fpu_syscall.c @@ -14,12 +14,11 @@ #include <stdlib.h> #include "utils.h" +#include "fpu.h" extern int test_fpu(double *darray, pid_t *pid); -double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, - 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, - 2.1}; +double darray[32]; int syscall_fpu(void) { @@ -27,6 +26,9 @@ int syscall_fpu(void) int i; int ret; int child_ret; + + randomise_darray(darray, ARRAY_SIZE(darray)); + for (i = 0; i < 1000; i++) { /* test_fpu will fork() */ ret = test_fpu(darray, &fork_pid);
There is a selftest that checks if FPRs are corrupted across a fork, aka clone. It was added as part of the series that optimised the clone path to save the parent's FP state without "giving up" (turning off FP). See commit 8792468da5e1 ("powerpc: Add the ability to save FPU without giving it up"). The test encodes the assumption that FPRs 0-13 are volatile across the syscall, by only checking the volatile FPRs are not changed by the fork. There was also a comment in the fpu_preempt test alluding to that: The check_fpu function in asm only checks the non volatile registers as it is reused from the syscall test It is true that the function call ABI treats f0-f13 as volatile, however the syscall ABI has since been documented as *not* treating those registers as volatile. See commit 7b8845a2a2ec ("powerpc/64: Document the syscall ABI"). So change the test to check all FPRs are not corrupted by the syscall. Note that this currently fails, because save_fpu() etc. do not restore f0/vsr0. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- tools/testing/selftests/powerpc/math/fpu_asm.S | 7 ++++--- tools/testing/selftests/powerpc/math/fpu_syscall.c | 8 +++++--- 2 files changed, 9 insertions(+), 6 deletions(-)