ptrace and perf watchpoints can't co-exists if their address range overlaps. See commit 29da4f91c0c1 ("powerpc/watchpoint: Don't allow concurrent perf and ptrace events") for more detail. Add selftest for the same.
Sample o/p: # ./ptrace-perf-hwbreak test: ptrace-perf-hwbreak tags: git_version:powerpc-5.8-7-118-g937fa174a15d-dirty perf cpu event -> ptrace thread event (Overlapping): Ok perf cpu event -> ptrace thread event (Non-overlapping): Ok perf thread event -> ptrace same thread event (Overlapping): Ok perf thread event -> ptrace same thread event (Non-overlapping): Ok perf thread event -> ptrace other thread event: Ok ptrace thread event -> perf kernel event: Ok ptrace thread event -> perf same thread event (Overlapping): Ok ptrace thread event -> perf same thread event (Non-overlapping): Ok ptrace thread event -> perf other thread event: Ok ptrace thread event -> perf cpu event (Overlapping): Ok ptrace thread event -> perf cpu event (Non-overlapping): Ok ptrace thread event -> perf same thread & cpu event (Overlapping): Ok ptrace thread event -> perf same thread & cpu event (Non-overlapping): Ok ptrace thread event -> perf other thread & cpu event: Ok success: ptrace-perf-hwbreak
Signed-off-by: Ravi Bangoria ravi.bangoria@linux.ibm.com --- .../selftests/powerpc/ptrace/.gitignore | 1 + .../testing/selftests/powerpc/ptrace/Makefile | 2 +- .../powerpc/ptrace/ptrace-perf-hwbreak.c | 659 ++++++++++++++++++ 3 files changed, 661 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c
diff --git a/tools/testing/selftests/powerpc/ptrace/.gitignore b/tools/testing/selftests/powerpc/ptrace/.gitignore index 0e96150b7c7e..eb75e5360e31 100644 --- a/tools/testing/selftests/powerpc/ptrace/.gitignore +++ b/tools/testing/selftests/powerpc/ptrace/.gitignore @@ -14,3 +14,4 @@ perf-hwbreak core-pkey ptrace-pkey ptrace-syscall +ptrace-perf-hwbreak diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile index 8d3f006c98cc..a500639da97a 100644 --- a/tools/testing/selftests/powerpc/ptrace/Makefile +++ b/tools/testing/selftests/powerpc/ptrace/Makefile @@ -2,7 +2,7 @@ TEST_GEN_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \ ptrace-tar ptrace-tm-tar ptrace-tm-spd-tar ptrace-vsx ptrace-tm-vsx \ ptrace-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak ptrace-pkey core-pkey \ - perf-hwbreak ptrace-syscall + perf-hwbreak ptrace-syscall ptrace-perf-hwbreak
top_srcdir = ../../../../.. include ../../lib.mk diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c new file mode 100644 index 000000000000..fad14f926b98 --- /dev/null +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c @@ -0,0 +1,659 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include <stdio.h> +#include <string.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <linux/hw_breakpoint.h> +#include <linux/perf_event.h> +#include <asm/unistd.h> +#include <sys/ptrace.h> +#include <sys/wait.h> +#include "ptrace.h" + +char data[16]; + +/* Overlapping address range */ +volatile __u64 *ptrace_data1 = (__u64 *)&data[0]; +volatile __u64 *perf_data1 = (__u64 *)&data[4]; + +/* Non-overlapping address range */ +volatile __u64 *ptrace_data2 = (__u64 *)&data[0]; +volatile __u64 *perf_data2 = (__u64 *)&data[8]; + +static unsigned long pid_max_addr(void) +{ + FILE *fp; + char *line, *c; + char addr[100]; + size_t len = 0; + + fp = fopen("/proc/kallsyms", "r"); + if (!fp) { + printf("Failed to read /proc/kallsyms. Exiting..\n"); + exit(EXIT_FAILURE); + } + + while (getline(&line, &len, fp) != -1) { + if (!strstr(line, "pid_max") || strstr(line, "pid_max_max") || + strstr(line, "pid_max_min")) + continue; + + strncpy(addr, line, len < 100 ? len : 100); + c = strchr(addr, ' '); + *c = '\0'; + return strtoul(addr, &c, 16); + } + fclose(fp); + printf("Could not find pix_max. Exiting..\n"); + exit(EXIT_FAILURE); + return -1; +} + +static void perf_user_event_attr_set(struct perf_event_attr *attr, __u64 addr, __u64 len) +{ + memset(attr, 0, sizeof(struct perf_event_attr)); + attr->type = PERF_TYPE_BREAKPOINT; + attr->size = sizeof(struct perf_event_attr); + attr->bp_type = HW_BREAKPOINT_R; + attr->bp_addr = addr; + attr->bp_len = len; + attr->exclude_kernel = 1; + attr->exclude_hv = 1; +} + +static void perf_kernel_event_attr_set(struct perf_event_attr *attr) +{ + memset(attr, 0, sizeof(struct perf_event_attr)); + attr->type = PERF_TYPE_BREAKPOINT; + attr->size = sizeof(struct perf_event_attr); + attr->bp_type = HW_BREAKPOINT_R; + attr->bp_addr = pid_max_addr(); + attr->bp_len = sizeof(unsigned long); + attr->exclude_user = 1; + attr->exclude_hv = 1; +} + +static int perf_cpu_event_open(int cpu, __u64 addr, __u64 len) +{ + struct perf_event_attr attr; + + perf_user_event_attr_set(&attr, addr, len); + return syscall(__NR_perf_event_open, &attr, -1, cpu, -1, 0); +} + +static int perf_thread_event_open(pid_t child_pid, __u64 addr, __u64 len) +{ + struct perf_event_attr attr; + + perf_user_event_attr_set(&attr, addr, len); + return syscall(__NR_perf_event_open, &attr, child_pid, -1, -1, 0); +} + +static int perf_thread_cpu_event_open(pid_t child_pid, int cpu, __u64 addr, __u64 len) +{ + struct perf_event_attr attr; + + perf_user_event_attr_set(&attr, addr, len); + return syscall(__NR_perf_event_open, &attr, child_pid, cpu, -1, 0); +} + +static int perf_thread_kernel_event_open(pid_t child_pid) +{ + struct perf_event_attr attr; + + perf_kernel_event_attr_set(&attr); + return syscall(__NR_perf_event_open, &attr, child_pid, -1, -1, 0); +} + +static int perf_cpu_kernel_event_open(int cpu) +{ + struct perf_event_attr attr; + + perf_kernel_event_attr_set(&attr); + return syscall(__NR_perf_event_open, &attr, -1, cpu, -1, 0); +} + +static int child(void) +{ + int ret; + + ret = ptrace(PTRACE_TRACEME, 0, NULL, 0); + if (ret) { + printf("Error: PTRACE_TRACEME failed\n"); + return 0; + } + kill(getpid(), SIGUSR1); /* --> parent (SIGUSR1) */ + + return 0; +} + +static void ptrace_ppc_hw_breakpoint(struct ppc_hw_breakpoint *info, int type, + __u64 addr, int len) +{ + info->version = 1; + info->trigger_type = type; + info->condition_mode = PPC_BREAKPOINT_CONDITION_NONE; + info->addr = addr; + info->addr2 = addr + len; + info->condition_value = 0; + if (!len) + info->addr_mode = PPC_BREAKPOINT_MODE_EXACT; + else + info->addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE; +} + +static int ptrace_open(pid_t child_pid, __u64 wp_addr, int len) +{ + struct ppc_hw_breakpoint info; + + ptrace_ppc_hw_breakpoint(&info, PPC_BREAKPOINT_TRIGGER_RW, wp_addr, len); + return ptrace(PPC_PTRACE_SETHWDEBUG, child_pid, 0, &info); +} + +static int test1(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by ptrace) + * if (existing cpu event by perf) + * if (addr range overlaps) + * fail; + */ + + perf_fd = perf_cpu_event_open(0, (__u64)perf_data1, sizeof(*perf_data1)); + if (perf_fd < 0) + return -1; + + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd > 0 || errno != ENOSPC) + ret = -1; + + close(perf_fd); + return ret; +} + +static int test2(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by ptrace) + * if (existing cpu event by perf) + * if (addr range does not overlaps) + * allow; + */ + + perf_fd = perf_cpu_event_open(0, (__u64)perf_data2, sizeof(*perf_data2)); + if (perf_fd < 0) + return -1; + + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data2, sizeof(*ptrace_data2)); + if (ptrace_fd < 0) { + ret = -1; + goto perf_close; + } + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + +perf_close: + close(perf_fd); + return ret; +} + +static int test3(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by ptrace) + * if (existing thread event by perf on the same thread) + * if (addr range overlaps) + * fail; + */ + perf_fd = perf_thread_event_open(child_pid, (__u64)perf_data1, + sizeof(*perf_data1)); + if (perf_fd < 0) + return -1; + + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd > 0 || errno != ENOSPC) + ret = -1; + + close(perf_fd); + return ret; +} + +static int test4(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by ptrace) + * if (existing thread event by perf on the same thread) + * if (addr range does not overlaps) + * fail; + */ + perf_fd = perf_thread_event_open(child_pid, (__u64)perf_data2, + sizeof(*perf_data2)); + if (perf_fd < 0) + return -1; + + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data2, sizeof(*ptrace_data2)); + if (ptrace_fd < 0) { + ret = -1; + goto perf_close; + } + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + +perf_close: + close(perf_fd); + return ret; +} + +static int test5(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int cpid; + int ret = 0; + + /* Test: + * if (new per thread event by ptrace) + * if (existing thread event by perf on the different thread) + * allow; + */ + cpid = fork(); + if (!cpid) { + /* Temporary Child */ + pause(); + exit(EXIT_SUCCESS); + } + + perf_fd = perf_thread_event_open(cpid, (__u64)perf_data1, sizeof(*perf_data1)); + if (perf_fd < 0) { + ret = -1; + goto kill_child; + } + + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) { + ret = -1; + goto perf_close; + } + + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); +perf_close: + close(perf_fd); +kill_child: + kill(cpid, SIGINT); + return ret; +} + +static int test6(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread kernel event by perf) + * if (existing thread event by ptrace on the same thread) + * allow; + * -- OR -- + * if (new per cpu kernel event by perf) + * if (existing thread event by ptrace) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_thread_kernel_event_open(child_pid); + if (perf_fd < 0) { + ret = -1; + goto ptrace_close; + } + close(perf_fd); + + perf_fd = perf_cpu_kernel_event_open(0); + if (perf_fd < 0) { + ret = -1; + goto ptrace_close; + } + close(perf_fd); + +ptrace_close: + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test7(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range overlaps) + * fail; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_thread_event_open(child_pid, (__u64)perf_data1, + sizeof(*perf_data1)); + if (perf_fd > 0 || errno != ENOSPC) + ret = -1; + + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test8(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range does not overlaps) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data2, sizeof(*ptrace_data2)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_thread_event_open(child_pid, (__u64)perf_data2, + sizeof(*perf_data2)); + if (perf_fd < 0) { + ret = -1; + goto ptrace_close; + } + close(perf_fd); + +ptrace_close: + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test9(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int cpid; + int ret = 0; + + /* Test: + * if (new per thread event by perf) + * if (existing thread event by ptrace on the other thread) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + cpid = fork(); + if (!cpid) { + /* Temporary Child */ + pause(); + exit(EXIT_SUCCESS); + } + + perf_fd = perf_thread_event_open(cpid, (__u64)perf_data1, sizeof(*perf_data1)); + if (perf_fd < 0) { + ret = -1; + goto kill_child; + } + close(perf_fd); + +kill_child: + kill(cpid, SIGINT); + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test10(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per cpu event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range overlaps) + * fail; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_cpu_event_open(0, (__u64)perf_data1, sizeof(*perf_data1)); + if (perf_fd > 0 || errno != ENOSPC) + ret = -1; + + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test11(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per cpu event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range does not overlap) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data2, sizeof(*ptrace_data2)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_cpu_event_open(0, (__u64)perf_data2, sizeof(*perf_data2)); + if (perf_fd < 0) { + ret = -1; + goto ptrace_close; + } + close(perf_fd); + +ptrace_close: + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test12(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread and per cpu event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range overlaps) + * fail; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_thread_cpu_event_open(child_pid, 0, (__u64)perf_data1, sizeof(*perf_data1)); + if (perf_fd > 0 || errno != ENOSPC) + ret = -1; + + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test13(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int ret = 0; + + /* Test: + * if (new per thread and per cpu event by perf) + * if (existing thread event by ptrace on the same thread) + * if (addr range does not overlap) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data2, sizeof(*ptrace_data2)); + if (ptrace_fd < 0) + return -1; + + perf_fd = perf_thread_cpu_event_open(child_pid, 0, (__u64)perf_data2, sizeof(*perf_data2)); + if (perf_fd < 0) { + ret = -1; + goto ptrace_close; + } + close(perf_fd); + +ptrace_close: + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int test14(pid_t child_pid) +{ + int perf_fd; + int ptrace_fd; + int cpid; + int ret = 0; + + /* Test: + * if (new per thread and per cpu event by perf) + * if (existing thread event by ptrace on the other thread) + * allow; + */ + ptrace_fd = ptrace_open(child_pid, (__u64)ptrace_data1, sizeof(*ptrace_data1)); + if (ptrace_fd < 0) + return -1; + + cpid = fork(); + if (!cpid) { + /* Temporary Child */ + pause(); + exit(EXIT_SUCCESS); + } + + perf_fd = perf_thread_cpu_event_open(cpid, 0, (__u64)perf_data1, + sizeof(*perf_data1)); + if (perf_fd < 0) { + ret = -1; + goto kill_child; + } + close(perf_fd); + +kill_child: + kill(cpid, SIGINT); + ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, ptrace_fd); + return ret; +} + +static int do_test(const char *msg, int (*fun)(pid_t arg), pid_t arg) +{ + int ret; + + ret = fun(arg); + if (ret) + printf("%s: Error\n", msg); + else + printf("%s: Ok\n", msg); + return ret; +} + +char *desc[14] = { + "perf cpu event -> ptrace thread event (Overlapping)", + "perf cpu event -> ptrace thread event (Non-overlapping)", + "perf thread event -> ptrace same thread event (Overlapping)", + "perf thread event -> ptrace same thread event (Non-overlapping)", + "perf thread event -> ptrace other thread event", + "ptrace thread event -> perf kernel event", + "ptrace thread event -> perf same thread event (Overlapping)", + "ptrace thread event -> perf same thread event (Non-overlapping)", + "ptrace thread event -> perf other thread event", + "ptrace thread event -> perf cpu event (Overlapping)", + "ptrace thread event -> perf cpu event (Non-overlapping)", + "ptrace thread event -> perf same thread & cpu event (Overlapping)", + "ptrace thread event -> perf same thread & cpu event (Non-overlapping)", + "ptrace thread event -> perf other thread & cpu event", +}; + +static int test(pid_t child_pid) +{ + int ret = TEST_PASS; + + ret |= do_test(desc[0], test1, child_pid); + ret |= do_test(desc[1], test2, child_pid); + ret |= do_test(desc[2], test3, child_pid); + ret |= do_test(desc[3], test4, child_pid); + ret |= do_test(desc[4], test5, child_pid); + ret |= do_test(desc[5], test6, child_pid); + ret |= do_test(desc[6], test7, child_pid); + ret |= do_test(desc[7], test8, child_pid); + ret |= do_test(desc[8], test9, child_pid); + ret |= do_test(desc[9], test10, child_pid); + ret |= do_test(desc[10], test11, child_pid); + ret |= do_test(desc[11], test12, child_pid); + ret |= do_test(desc[12], test13, child_pid); + ret |= do_test(desc[13], test14, child_pid); + + return ret; +} + +static void get_dbginfo(pid_t child_pid, struct ppc_debug_info *dbginfo) +{ + if (ptrace(PPC_PTRACE_GETHWDBGINFO, child_pid, NULL, dbginfo)) { + perror("Can't get breakpoint info"); + exit(-1); + } +} + +static int ptrace_perf_hwbreak(void) +{ + int ret; + pid_t child_pid; + struct ppc_debug_info dbginfo; + + child_pid = fork(); + if (!child_pid) + return child(); + + /* parent */ + wait(NULL); /* <-- child (SIGUSR1) */ + + get_dbginfo(child_pid, &dbginfo); + SKIP_IF(dbginfo.num_data_bps <= 1); + + ret = perf_cpu_event_open(0, (__u64)perf_data1, sizeof(*perf_data1)); + SKIP_IF(ret < 0); + close(ret); + + ret = test(child_pid); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + return ret; +} + +int main(int argc, char *argv[]) +{ + return test_harness(ptrace_perf_hwbreak, "ptrace-perf-hwbreak"); +}