diff options
| -rw-r--r-- | tools/testing/selftests/powerpc/mm/.gitignore | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/mm/Makefile | 8 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c | 233 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/mm/stack_expansion_signal.c | 118 | ||||
| -rw-r--r-- | tools/testing/selftests/powerpc/pmu/lib.h | 1 |
5 files changed, 361 insertions, 1 deletions
diff --git a/tools/testing/selftests/powerpc/mm/.gitignore b/tools/testing/selftests/powerpc/mm/.gitignore index 0323892a8032..91c775c23c66 100644 --- a/tools/testing/selftests/powerpc/mm/.gitignore +++ b/tools/testing/selftests/powerpc/mm/.gitignore @@ -9,3 +9,5 @@ bad_accesses tlbie_test pkey_exec_prot pkey_siginfo +stack_expansion_ldst +stack_expansion_signal diff --git a/tools/testing/selftests/powerpc/mm/Makefile b/tools/testing/selftests/powerpc/mm/Makefile index 740f7854548e..250ce172e0da 100644 --- a/tools/testing/selftests/powerpc/mm/Makefile +++ b/tools/testing/selftests/powerpc/mm/Makefile @@ -4,7 +4,8 @@ noarg: TEST_GEN_PROGS := hugetlb_vs_thp_test subpage_prot segv_errors wild_bctr \ large_vm_fork_separation bad_accesses pkey_exec_prot \ - pkey_siginfo + pkey_siginfo stack_expansion_signal stack_expansion_ldst + TEST_GEN_PROGS_EXTENDED := tlbie_test TEST_GEN_FILES := tempfile @@ -19,6 +20,11 @@ $(OUTPUT)/bad_accesses: CFLAGS += -m64 $(OUTPUT)/pkey_exec_prot: CFLAGS += -m64 $(OUTPUT)/pkey_siginfo: CFLAGS += -m64 +$(OUTPUT)/stack_expansion_signal: ../utils.c ../pmu/lib.c + +$(OUTPUT)/stack_expansion_ldst: CFLAGS += -fno-stack-protector +$(OUTPUT)/stack_expansion_ldst: ../utils.c + $(OUTPUT)/tempfile: dd if=/dev/zero of=$@ bs=64k count=1 diff --git a/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c b/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c new file mode 100644 index 000000000000..0587e11437f5 --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test that loads/stores expand the stack segment, or trigger a SEGV, in + * various conditions. + * + * Based on test code by Tom Lane. + */ + +#undef NDEBUG +#include <assert.h> + +#include <err.h> +#include <errno.h> +#include <stdio.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <sys/resource.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#define _KB (1024) +#define _MB (1024 * 1024) + +volatile char *stack_top_ptr; +volatile unsigned long stack_top_sp; +volatile char c; + +enum access_type { + LOAD, + STORE, +}; + +/* + * Consume stack until the stack pointer is below @target_sp, then do an access + * (load or store) at offset @delta from either the base of the stack or the + * current stack pointer. + */ +__attribute__ ((noinline)) +int consume_stack(unsigned long target_sp, unsigned long stack_high, int delta, enum access_type type) +{ + unsigned long target; + char stack_cur; + + if ((unsigned long)&stack_cur > target_sp) + return consume_stack(target_sp, stack_high, delta, type); + else { + // We don't really need this, but without it GCC might not + // generate a recursive call above. + stack_top_ptr = &stack_cur; + +#ifdef __powerpc__ + asm volatile ("mr %[sp], %%r1" : [sp] "=r" (stack_top_sp)); +#else + asm volatile ("mov %%rsp, %[sp]" : [sp] "=r" (stack_top_sp)); +#endif + + // Kludge, delta < 0 indicates relative to SP + if (delta < 0) + target = stack_top_sp + delta; + else + target = stack_high - delta + 1; + + volatile char *p = (char *)target; + + if (type == STORE) + *p = c; + else + c = *p; + + // Do something to prevent the stack frame being popped prior to + // our access above. + getpid(); + } + + return 0; +} + +static int search_proc_maps(char *needle, unsigned long *low, unsigned long *high) +{ + unsigned long start, end; + static char buf[4096]; + char name[128]; + FILE *f; + int rc; + + f = fopen("/proc/self/maps", "r"); + if (!f) { + perror("fopen"); + return -1; + } + + while (fgets(buf, sizeof(buf), f)) { + rc = sscanf(buf, "%lx-%lx %*c%*c%*c%*c %*x %*d:%*d %*d %127s\n", + &start, &end, name); + if (rc == 2) + continue; + + if (rc != 3) { + printf("sscanf errored\n"); + rc = -1; + break; + } + + if (strstr(name, needle)) { + *low = start; + *high = end - 1; + rc = 0; + break; + } + } + + fclose(f); + + return rc; +} + +int child(unsigned int stack_used, int delta, enum access_type type) +{ + unsigned long low, stack_high; + + assert(search_proc_maps("[stack]", &low, &stack_high) == 0); + + assert(consume_stack(stack_high - stack_used, stack_high, delta, type) == 0); + + printf("Access OK: %s delta %-7d used size 0x%06x stack high 0x%lx top_ptr %p top sp 0x%lx actual used 0x%lx\n", + type == LOAD ? "load" : "store", delta, stack_used, stack_high, + stack_top_ptr, stack_top_sp, stack_high - stack_top_sp + 1); + + return 0; +} + +static int test_one(unsigned int stack_used, int delta, enum access_type type) +{ + pid_t pid; + int rc; + + pid = fork(); + if (pid == 0) + exit(child(stack_used, delta, type)); + + assert(waitpid(pid, &rc, 0) != -1); + + if (WIFEXITED(rc) && WEXITSTATUS(rc) == 0) + return 0; + + // We don't expect a non-zero exit that's not a signal + assert(!WIFEXITED(rc)); + + printf("Faulted: %s delta %-7d used size 0x%06x signal %d\n", + type == LOAD ? "load" : "store", delta, stack_used, + WTERMSIG(rc)); + + return 1; +} + +// This is fairly arbitrary but is well below any of the targets below, +// so that the delta between the stack pointer and the target is large. +#define DEFAULT_SIZE (32 * _KB) + +static void test_one_type(enum access_type type, unsigned long page_size, unsigned long rlim_cur) +{ + assert(test_one(DEFAULT_SIZE, 512 * _KB, type) == 0); + + // powerpc has a special case to allow up to 1MB + assert(test_one(DEFAULT_SIZE, 1 * _MB, type) == 0); + +#ifdef __powerpc__ + // This fails on powerpc because it's > 1MB and is not a stdu & + // not close to r1 + assert(test_one(DEFAULT_SIZE, 1 * _MB + 8, type) != 0); +#else + assert(test_one(DEFAULT_SIZE, 1 * _MB + 8, type) == 0); +#endif + +#ifdef __powerpc__ + // Accessing way past the stack pointer is not allowed on powerpc + assert(test_one(DEFAULT_SIZE, rlim_cur, type) != 0); +#else + // We should be able to access anywhere within the rlimit + assert(test_one(DEFAULT_SIZE, rlim_cur, type) == 0); +#endif + + // But if we go past the rlimit it should fail + assert(test_one(DEFAULT_SIZE, rlim_cur + 1, type) != 0); + + // Above 1MB powerpc only allows accesses within 2048 bytes of + // r1 for accesses that aren't stdu + assert(test_one(1 * _MB + page_size - 128, -2048, type) == 0); +#ifdef __powerpc__ + assert(test_one(1 * _MB + page_size - 128, -2049, type) != 0); +#else + assert(test_one(1 * _MB + page_size - 128, -2049, type) == 0); +#endif + + // By consuming 2MB of stack we test the stdu case + assert(test_one(2 * _MB + page_size - 128, -2048, type) == 0); +} + +static int test(void) +{ + unsigned long page_size; + struct rlimit rlimit; + + page_size = getpagesize(); + getrlimit(RLIMIT_STACK, &rlimit); + printf("Stack rlimit is 0x%lx\n", rlimit.rlim_cur); + + printf("Testing loads ...\n"); + test_one_type(LOAD, page_size, rlimit.rlim_cur); + printf("Testing stores ...\n"); + test_one_type(STORE, page_size, rlimit.rlim_cur); + + printf("All OK\n"); + + return 0; +} + +#ifdef __powerpc__ +#include "utils.h" + +int main(void) +{ + return test_harness(test, "stack_expansion_ldst"); +} +#else +int main(void) +{ + return test(); +} +#endif diff --git a/tools/testing/selftests/powerpc/mm/stack_expansion_signal.c b/tools/testing/selftests/powerpc/mm/stack_expansion_signal.c new file mode 100644 index 000000000000..c8b32a29e274 --- /dev/null +++ b/tools/testing/selftests/powerpc/mm/stack_expansion_signal.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test that signal delivery is able to expand the stack segment without + * triggering a SEGV. + * + * Based on test code by Tom Lane. + */ + +#include <err.h> +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <sys/types.h> +#include <unistd.h> + +#include "../pmu/lib.h" +#include "utils.h" + +#define _KB (1024) +#define _MB (1024 * 1024) + +static char *stack_base_ptr; +static char *stack_top_ptr; + +static volatile sig_atomic_t sig_occurred = 0; + +static void sigusr1_handler(int signal_arg) +{ + sig_occurred = 1; +} + +static int consume_stack(unsigned int stack_size, union pipe write_pipe) +{ + char stack_cur; + + if ((stack_base_ptr - &stack_cur) < stack_size) + return consume_stack(stack_size, write_pipe); + else { + stack_top_ptr = &stack_cur; + + FAIL_IF(notify_parent(write_pipe)); + + while (!sig_occurred) + barrier(); + } + + return 0; +} + +static int child(unsigned int stack_size, union pipe write_pipe) +{ + struct sigaction act; + char stack_base; + + act.sa_handler = sigusr1_handler; + sigemptyset(&act.sa_mask); + act.sa_flags = 0; + if (sigaction(SIGUSR1, &act, NULL) < 0) + err(1, "sigaction"); + + stack_base_ptr = (char *) (((size_t) &stack_base + 65535) & ~65535UL); + + FAIL_IF(consume_stack(stack_size, write_pipe)); + + printf("size 0x%06x: OK, stack base %p top %p (%zx used)\n", + stack_size, stack_base_ptr, stack_top_ptr, + stack_base_ptr - stack_top_ptr); + + return 0; +} + +static int test_one_size(unsigned int stack_size) +{ + union pipe read_pipe, write_pipe; + pid_t pid; + + FAIL_IF(pipe(read_pipe.fds) == -1); + FAIL_IF(pipe(write_pipe.fds) == -1); + + pid = fork(); + if (pid == 0) { + close(read_pipe.read_fd); + close(write_pipe.write_fd); + exit(child(stack_size, read_pipe)); + } + + close(read_pipe.write_fd); + close(write_pipe.read_fd); + FAIL_IF(sync_with_child(read_pipe, write_pipe)); + + kill(pid, SIGUSR1); + + FAIL_IF(wait_for_child(pid)); + + close(read_pipe.read_fd); + close(write_pipe.write_fd); + + return 0; +} + +int test(void) +{ + unsigned int i, size; + + // Test with used stack from 1MB - 64K to 1MB + 64K + // Increment by 64 to get more coverage of odd sizes + for (i = 0; i < (128 * _KB); i += 64) { + size = i + (1 * _MB) - (64 * _KB); + FAIL_IF(test_one_size(size)); + } + + return 0; +} + +int main(void) +{ + return test_harness(test, "stack_expansion_signal"); +} diff --git a/tools/testing/selftests/powerpc/pmu/lib.h b/tools/testing/selftests/powerpc/pmu/lib.h index fa12e7d0b4d3..bf1bec013bbb 100644 --- a/tools/testing/selftests/powerpc/pmu/lib.h +++ b/tools/testing/selftests/powerpc/pmu/lib.h @@ -6,6 +6,7 @@ #ifndef __SELFTESTS_POWERPC_PMU_LIB_H #define __SELFTESTS_POWERPC_PMU_LIB_H +#include <stdbool.h> #include <stdio.h> #include <stdint.h> #include <string.h> |