Hi Sandipan,
Sandipan Das sandipan@linux.ibm.com writes:
diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c new file mode 100644 index 000000000000..b346ad205e68 --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c @@ -0,0 +1,326 @@ +// SPDX-License-Identifier: GPL-2.0+
+/*
- Copyright 2020, Sandipan Das, IBM Corp.
- Test if applying execute protection on pages using memory
- protection keys works as expected.
- */
+#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <signal.h>
+#include <time.h> +#include <unistd.h> +#include <sys/mman.h>
+#include "utils.h"
+/* Override definitions as they might be inconsistent */ +#undef PKEY_DISABLE_ACCESS +#define PKEY_DISABLE_ACCESS 0x3
Why would they be inconsistent?
+/* Older distros might not define this */ +#ifndef SEGV_PKUERR +#define SEGV_PKUERR 4 +#endif
...
- /* Restore permissions in order to continue */
- switch (fcode) {
- case SEGV_ACCERR:
if (mprotect(insns, pgsize, PROT_READ | PROT_WRITE)) {perror("mprotect");goto fail;}break;- case SEGV_PKUERR:
if (sinfo->si_pkey != fpkey)goto fail;
This doesn't compile on older distros, eg Ubuntu 16.04:
pkey_exec_prot.c: In function 'segv_handler': pkey_exec_prot.c:121:12: error: 'siginfo_t {aka struct <anonymous>}' has no member named 'si_pkey' if (sinfo->si_pkey != fpkey) ^ pkey_exec_prot.c:151:24: error: 'siginfo_t {aka struct <anonymous>}' has no member named 'si_pkey' pkey_set_rights(sinfo->si_pkey, 0); ^ ../../lib.mk:142: recipe for target '/output/kselftest/powerpc/mm/pkey_exec_prot' failed
I think a reasonable solution is to use the absence of SEGV_PKUERR to basically turn the whole test into a nop at build time, eg:
diff --git a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c index b346ad205e68..218257b89fbb 100644 --- a/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c +++ b/tools/testing/selftests/powerpc/mm/pkey_exec_prot.c @@ -30,9 +30,7 @@ #define PKEY_DISABLE_EXECUTE 0x4
/* Older distros might not define this */ -#ifndef SEGV_PKUERR -#define SEGV_PKUERR 4 -#endif +#ifdef SEGV_PKUERR
#define SYS_pkey_mprotect 386 #define SYS_pkey_alloc 384 @@ -319,6 +317,13 @@ static int test(void)
return 0; } +#else +static int test(void) +{ + printf("Test built with old libc lacking pkey support.\n"); + SKIP_IF(true); +} +#endif /* SEGV_PKUERR */
int main(void) {
cheers