On Thu, Oct 26, 2023 at 01:06:27AM +0530, Swarup Laxman Kotiaklapudi wrote:
Check ProtectionKey field in /proc/*/smaps output, if system supports page-based memory permissions.
--- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -37,6 +37,7 @@ #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> +#include "../kselftest.h"
I'd rather not include stuff. The reason is that this include makes the test not (less) self-contained so it requires copying two files to some machine where it is broken for debugging.
@@ -83,10 +84,7 @@ static const char proc_pid_smaps_vsyscall_1[] = "SwapPss: 0 kB\n" "Locked: 0 kB\n" "THPeligible: 0\n" -/*
- "ProtectionKey:" field is conditional. It is possible to check it as well,
- but I don't have such machine.
- */
+"ProtectionKey: 0\n" ; static const char proc_pid_smaps_vsyscall_2[] = @@ -113,10 +111,7 @@ static const char proc_pid_smaps_vsyscall_2[] = "SwapPss: 0 kB\n" "Locked: 0 kB\n" "THPeligible: 0\n" -/*
- "ProtectionKey:" field is conditional. It is possible to check it as well,
- but I'm too tired.
- */
+"ProtectionKey: 0\n" ; static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) @@ -241,13 +236,26 @@ static int test_proc_pid_smaps(pid_t pid) } else { ssize_t rv = read(fd, buf, sizeof(buf)); close(fd);
if (g_vsyscall == 0) {assert(rv == 0);} else {size_t len = strlen(g_proc_pid_maps_vsyscall);/* TODO "ProtectionKey:" */assert(rv > len);assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0);
assert(rv >= 0);assert(rv <= sizeof(buf));if (g_vsyscall != 0) {int pkey = pkey_alloc(0, 0);
I'd call syscall(). glibc might not have pkey_alloc(3) [[citation needed]] And I'd move this pkey support testing to the very beginning (like vsyscall).
if (pkey < 0) {size_t len = strlen(g_proc_pid_maps_vsyscall);
OK this test was broken, but it is not your fault. See my next patch.
assert(rv > len);assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0);} else {pkey_free(pkey);static const char * const S[] = {"ProtectionKey: 0\n"};int i;for (i = 0; i < ARRAY_SIZE(S); i++)assert(memmem(buf, rv, S[i], strlen(S[i])));}
OK-ish.