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authorMichael Ellerman <mpe@ellerman.id.au>2022-06-28 00:02:38 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2022-07-25 12:05:16 +1000
commitc5a814cc992002c36fa5b7db5fbd55efb7430386 (patch)
treedd24cd9097f999e15db917b4ee6050fccbadfc18
parent7b1513d02edf4a6334618070641f47abbbef0cef (diff)
downloadlinux-c5a814cc992002c36fa5b7db5fbd55efb7430386.tar.bz2
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 <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220627140239.2464900-12-mpe@ellerman.id.au
-rw-r--r--tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c71
1 files 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 b574ea26395c..c5dcb8c02616 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 <time.h>
/* 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();