From c5a814cc992002c36fa5b7db5fbd55efb7430386 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 28 Jun 2022 00:02:38 +1000 Subject: [PATCH] selftests/powerpc/ptrace: Use more interesting values The ptrace-gpr test uses fixed values to test that registers can be read/written via ptrace. In particular it sets all GPRs to 1, which means the test could miss some types of bugs - eg. if the kernel was only returning the low word. So generate some random values at startup and use those instead. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220627140239.2464900-12-mpe@ellerman.id.au --- .../testing/selftests/powerpc/ptrace/ptrace-gpr.c | 71 +++++++++++++++++----- 1 file changed, 57 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c index b574ea2..c5dcb8c 100644 --- a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c @@ -7,18 +7,18 @@ #include "ptrace.h" #include "ptrace-gpr.h" #include "reg.h" +#include /* Tracer and Tracee Shared Data */ int shm_id; int *cptr, *pptr; -double a = FPR_1; -double b = FPR_2; -double c = FPR_3; - extern void gpr_child_loop(int *read_flag, int *write_flag, unsigned long *gpr_buf, double *fpr_buf); +unsigned long child_gpr_val, parent_gpr_val; +double child_fpr_val, parent_fpr_val; + static int child(void) { unsigned long gpr_buf[32]; @@ -30,16 +30,16 @@ static int child(void) memset(fpr_buf, 0, sizeof(fpr_buf)); for (i = 0; i < 32; i++) { - gpr_buf[i] = GPR_1; - fpr_buf[i] = a; + gpr_buf[i] = child_gpr_val; + fpr_buf[i] = child_fpr_val; } gpr_child_loop(&cptr[0], &cptr[1], gpr_buf, fpr_buf); shmdt((void *)cptr); - FAIL_IF(validate_gpr(gpr_buf, GPR_3)); - FAIL_IF(validate_fpr_double(fpr_buf, c)); + FAIL_IF(validate_gpr(gpr_buf, parent_gpr_val)); + FAIL_IF(validate_fpr_double(fpr_buf, parent_fpr_val)); return 0; } @@ -47,24 +47,67 @@ static int child(void) int trace_gpr(pid_t child) { unsigned long gpr[18]; - __u64 fpr[32]; + __u64 tmp, fpr[32]; FAIL_IF(start_trace(child)); FAIL_IF(show_gpr(child, gpr)); - FAIL_IF(validate_gpr(gpr, GPR_1)); + FAIL_IF(validate_gpr(gpr, child_gpr_val)); FAIL_IF(show_fpr(child, fpr)); - FAIL_IF(validate_fpr(fpr, FPR_1_REP)); - FAIL_IF(write_gpr(child, GPR_3)); - FAIL_IF(write_fpr(child, FPR_3_REP)); + + memcpy(&tmp, &child_fpr_val, sizeof(tmp)); + FAIL_IF(validate_fpr(fpr, tmp)); + + FAIL_IF(write_gpr(child, parent_gpr_val)); + + memcpy(&tmp, &parent_fpr_val, sizeof(tmp)); + FAIL_IF(write_fpr(child, tmp)); + FAIL_IF(stop_trace(child)); return TEST_PASS; } +#ifndef __LONG_WIDTH__ +#define __LONG_WIDTH__ (sizeof(long) * 8) +#endif + +static uint64_t rand_reg(void) +{ + uint64_t result; + long r; + + r = random(); + + // Small values are typical + result = r & 0xffff; + if (r & 0x10000) + return result; + + // Pointers tend to have high bits set + result |= random() << (__LONG_WIDTH__ - 31); + if (r & 0x100000) + return result; + + // And sometimes we want a full 64-bit value + result ^= random() << 16; + + return result; +} + int ptrace_gpr(void) { - pid_t pid; + unsigned long seed; int ret, status; + pid_t pid; + + seed = getpid() ^ time(NULL); + printf("srand(%lu)\n", seed); + srand(seed); + + child_gpr_val = rand_reg(); + child_fpr_val = rand_reg(); + parent_gpr_val = rand_reg(); + parent_fpr_val = rand_reg(); shm_id = shmget(IPC_PRIVATE, sizeof(int) * 2, 0777|IPC_CREAT); pid = fork(); -- 2.7.4