Power10 introduced 2nd watchpoint (DAWR). ISA 3.1, Book 3S, Ch 9 - 'Debug Facilities' covers the feature in detail. Kernel patches to enable the 2nd DAWR are already in[1], including kvm enablement[2]. These patches adds selftests for 2nd DAWR.
[1]: https://git.kernel.org/torvalds/c/deb2bd9bcc8428d4b65b6ba640ba8b57c1b20b17 [2]: https://git.kernel.org/torvalds/c/bd1de1a0e6eff4bde5ceae969673b85b8446fd6a
v2: https://lore.kernel.org/r/20210407054938.312857-1-ravi.bangoria@linux.ibm.co... v2->v3: - Fixed some checkpatch warnings
v1: https://lore.kernel.org/r/20200723102058.312282-1-ravi.bangoria@linux.ibm.co... v1->v2: - Kvm patches are already upstream - Rebased selftests to powerpc/next
Ravi Bangoria (4): powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR powerpc/selftests/perf-hwbreak: Coalesce event creation code powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR powerpc/selftests: Add selftest to test concurrent perf/ptrace events
.../selftests/powerpc/ptrace/.gitignore | 1 + .../testing/selftests/powerpc/ptrace/Makefile | 2 +- .../selftests/powerpc/ptrace/perf-hwbreak.c | 631 +++++++++++++++-- .../selftests/powerpc/ptrace/ptrace-hwbreak.c | 79 +++ .../powerpc/ptrace/ptrace-perf-hwbreak.c | 659 ++++++++++++++++++ 5 files changed, 1330 insertions(+), 42 deletions(-) create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-perf-hwbreak.c
Add selftests to test multiple active DAWRs with ptrace interface.
Sample o/p: $ ./ptrace-hwbreak ... PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW ALIGNED, WO, len: 6: Ok PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW UNALIGNED, RO, len: 6: Ok PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, WO, len: 6: Ok PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, RO, len: 6: Ok
Signed-off-by: Ravi Bangoria ravi.bangoria@linux.ibm.com Reviewed-by: Daniel Axtens dja@axtens.net --- .../selftests/powerpc/ptrace/ptrace-hwbreak.c | 79 +++++++++++++++++++ 1 file changed, 79 insertions(+)
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c index 2e0d86e0687e..a0635a3819aa 100644 --- a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c @@ -194,6 +194,18 @@ static void test_workload(void) big_var[rand() % DAWR_MAX_LEN] = 'a'; else cvar = big_var[rand() % DAWR_MAX_LEN]; + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW ALIGNED, WO test */ + gstruct.a[rand() % A_LEN] = 'a'; + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW UNALIGNED, RO test */ + cvar = gstruct.b[rand() % B_LEN]; + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, WO test */ + gstruct.a[rand() % A_LEN] = 'a'; + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, RO test */ + cvar = gstruct.a[rand() % A_LEN]; }
static void check_success(pid_t child_pid, const char *name, const char *type, @@ -417,6 +429,69 @@ static void test_sethwdebug_range_aligned(pid_t child_pid) ptrace_delhwdebug(child_pid, wh); }
+static void test_multi_sethwdebug_range(pid_t child_pid) +{ + struct ppc_hw_breakpoint info1, info2; + unsigned long wp_addr1, wp_addr2; + char *name1 = "PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW ALIGNED"; + char *name2 = "PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW UNALIGNED"; + int len1, len2; + int wh1, wh2; + + wp_addr1 = (unsigned long)&gstruct.a; + wp_addr2 = (unsigned long)&gstruct.b; + len1 = A_LEN; + len2 = B_LEN; + get_ppc_hw_breakpoint(&info1, PPC_BREAKPOINT_TRIGGER_WRITE, wp_addr1, len1); + get_ppc_hw_breakpoint(&info2, PPC_BREAKPOINT_TRIGGER_READ, wp_addr2, len2); + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW ALIGNED, WO test */ + wh1 = ptrace_sethwdebug(child_pid, &info1); + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DW UNALIGNED, RO test */ + wh2 = ptrace_sethwdebug(child_pid, &info2); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success(child_pid, name1, "WO", wp_addr1, len1); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success(child_pid, name2, "RO", wp_addr2, len2); + + ptrace_delhwdebug(child_pid, wh1); + ptrace_delhwdebug(child_pid, wh2); +} + +static void test_multi_sethwdebug_range_dawr_overlap(pid_t child_pid) +{ + struct ppc_hw_breakpoint info1, info2; + unsigned long wp_addr1, wp_addr2; + char *name = "PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap"; + int len1, len2; + int wh1, wh2; + + wp_addr1 = (unsigned long)&gstruct.a; + wp_addr2 = (unsigned long)&gstruct.a; + len1 = A_LEN; + len2 = A_LEN; + get_ppc_hw_breakpoint(&info1, PPC_BREAKPOINT_TRIGGER_WRITE, wp_addr1, len1); + get_ppc_hw_breakpoint(&info2, PPC_BREAKPOINT_TRIGGER_READ, wp_addr2, len2); + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, WO test */ + wh1 = ptrace_sethwdebug(child_pid, &info1); + + /* PPC_PTRACE_SETHWDEBUG 2, MODE_RANGE, DAWR Overlap, RO test */ + wh2 = ptrace_sethwdebug(child_pid, &info2); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success(child_pid, name, "WO", wp_addr1, len1); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success(child_pid, name, "RO", wp_addr2, len2); + + ptrace_delhwdebug(child_pid, wh1); + ptrace_delhwdebug(child_pid, wh2); +} + static void test_sethwdebug_range_unaligned(pid_t child_pid) { struct ppc_hw_breakpoint info; @@ -504,6 +579,10 @@ run_tests(pid_t child_pid, struct ppc_debug_info *dbginfo, bool dawr) test_sethwdebug_range_unaligned(child_pid); test_sethwdebug_range_unaligned_dar(child_pid); test_sethwdebug_dawr_max_range(child_pid); + if (dbginfo->num_data_bps > 1) { + test_multi_sethwdebug_range(child_pid); + test_multi_sethwdebug_range_dawr_overlap(child_pid); + } } } }
perf-hwbreak selftest opens hw-breakpoint event at multiple places for which it has same code repeated. Coalesce that code into a function.
Signed-off-by: Ravi Bangoria ravi.bangoria@linux.ibm.com --- .../selftests/powerpc/ptrace/perf-hwbreak.c | 79 +++++++++---------- 1 file changed, 39 insertions(+), 40 deletions(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c index c1f324afdbf3..b1d5a14d7722 100644 --- a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c +++ b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c @@ -34,28 +34,46 @@
#define DAWR_LENGTH_MAX ((0x3f + 1) * 8)
-static inline int sys_perf_event_open(struct perf_event_attr *attr, pid_t pid, - int cpu, int group_fd, - unsigned long flags) +static void perf_event_attr_set(struct perf_event_attr *attr, + __u32 type, __u64 addr, __u64 len, + bool exclude_user) { - attr->size = sizeof(*attr); - return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); + memset(attr, 0, sizeof(struct perf_event_attr)); + attr->type = PERF_TYPE_BREAKPOINT; + attr->size = sizeof(struct perf_event_attr); + attr->bp_type = type; + attr->bp_addr = addr; + attr->bp_len = len; + attr->exclude_kernel = 1; + attr->exclude_hv = 1; + attr->exclude_guest = 1; + attr->exclude_user = exclude_user; + attr->disabled = 1; }
-static inline bool breakpoint_test(int len) +static int +perf_process_event_open_exclude_user(__u32 type, __u64 addr, __u64 len, bool exclude_user) { struct perf_event_attr attr; + + perf_event_attr_set(&attr, type, addr, len, exclude_user); + return syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); +} + +static int perf_process_event_open(__u32 type, __u64 addr, __u64 len) +{ + struct perf_event_attr attr; + + perf_event_attr_set(&attr, type, addr, len, 0); + return syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); +} + +static inline bool breakpoint_test(int len) +{ int fd;
- /* setup counters */ - memset(&attr, 0, sizeof(attr)); - attr.disabled = 1; - attr.type = PERF_TYPE_BREAKPOINT; - attr.bp_type = HW_BREAKPOINT_R; /* bp_addr can point anywhere but needs to be aligned */ - attr.bp_addr = (__u64)(&attr) & 0xfffffffffffff800; - attr.bp_len = len; - fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + fd = perf_process_event_open(HW_BREAKPOINT_R, (__u64)(&fd) & 0xfffffffffffff800, len); if (fd < 0) return false; close(fd); @@ -75,7 +93,6 @@ static inline bool dawr_supported(void) static int runtestsingle(int readwriteflag, int exclude_user, int arraytest) { int i,j; - struct perf_event_attr attr; size_t res; unsigned long long breaks, needed; int readint; @@ -85,6 +102,7 @@ static int runtestsingle(int readwriteflag, int exclude_user, int arraytest) int break_fd; int loop_num = MAX_LOOPS - (rand() % 100); /* provide some variability */ volatile int *k; + __u64 len;
/* align to 0x400 boundary as required by DAWR */ readintalign = (int *)(((unsigned long)readintarraybig + 0x7ff) & @@ -94,19 +112,11 @@ static int runtestsingle(int readwriteflag, int exclude_user, int arraytest) if (arraytest) ptr = &readintalign[0];
- /* setup counters */ - memset(&attr, 0, sizeof(attr)); - attr.disabled = 1; - attr.type = PERF_TYPE_BREAKPOINT; - attr.bp_type = readwriteflag; - attr.bp_addr = (__u64)ptr; - attr.bp_len = sizeof(int); - if (arraytest) - attr.bp_len = DAWR_LENGTH_MAX; - attr.exclude_user = exclude_user; - break_fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + len = arraytest ? DAWR_LENGTH_MAX : sizeof(int); + break_fd = perf_process_event_open_exclude_user(readwriteflag, (__u64)ptr, + len, exclude_user); if (break_fd < 0) { - perror("sys_perf_event_open"); + perror("perf_process_event_open_exclude_user"); exit(1); }
@@ -153,7 +163,6 @@ static int runtest_dar_outside(void) void *target; volatile __u16 temp16; volatile __u64 temp64; - struct perf_event_attr attr; int break_fd; unsigned long long breaks; int fail = 0; @@ -165,21 +174,11 @@ static int runtest_dar_outside(void) exit(EXIT_FAILURE); }
- /* setup counters */ - memset(&attr, 0, sizeof(attr)); - attr.disabled = 1; - attr.type = PERF_TYPE_BREAKPOINT; - attr.exclude_kernel = 1; - attr.exclude_hv = 1; - attr.exclude_guest = 1; - attr.bp_type = HW_BREAKPOINT_RW; /* watch middle half of target array */ - attr.bp_addr = (__u64)(target + 2); - attr.bp_len = 4; - break_fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + break_fd = perf_process_event_open(HW_BREAKPOINT_RW, (__u64)(target + 2), 4); if (break_fd < 0) { free(target); - perror("sys_perf_event_open"); + perror("perf_process_event_open"); exit(EXIT_FAILURE); }
Extend perf-hwbreak.c selftest to test multiple DAWRs. Also add testcase for testing 512 byte boundary removal.
Sample o/p: # ./perf-hwbreak ... TESTED: Process specific, Two events, diff addr TESTED: Process specific, Two events, same addr TESTED: Process specific, Two events, diff addr, one is RO, other is WO TESTED: Process specific, Two events, same addr, one is RO, other is WO TESTED: Systemwide, Two events, diff addr TESTED: Systemwide, Two events, same addr TESTED: Systemwide, Two events, diff addr, one is RO, other is WO TESTED: Systemwide, Two events, same addr, one is RO, other is WO TESTED: Process specific, 512 bytes, unaligned success: perf_hwbreak
Signed-off-by: Ravi Bangoria ravi.bangoria@linux.ibm.com --- .../selftests/powerpc/ptrace/perf-hwbreak.c | 552 +++++++++++++++++- 1 file changed, 551 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c index b1d5a14d7722..419506636ebe 100644 --- a/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c +++ b/tools/testing/selftests/powerpc/ptrace/perf-hwbreak.c @@ -21,8 +21,13 @@ #include <assert.h> #include <stdio.h> #include <stdlib.h> +#include <signal.h> #include <string.h> #include <sys/ioctl.h> +#include <sys/wait.h> +#include <sys/ptrace.h> +#include <sys/sysinfo.h> +#include <asm/ptrace.h> #include <elf.h> #include <pthread.h> #include <sys/syscall.h> @@ -34,6 +39,12 @@
#define DAWR_LENGTH_MAX ((0x3f + 1) * 8)
+int nprocs; + +static volatile int a = 10; +static volatile int b = 10; +static volatile char c[512 + 8] __attribute__((aligned(512))); + static void perf_event_attr_set(struct perf_event_attr *attr, __u32 type, __u64 addr, __u64 len, bool exclude_user) @@ -68,6 +79,76 @@ static int perf_process_event_open(__u32 type, __u64 addr, __u64 len) return syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); }
+static int perf_cpu_event_open(long cpu, __u32 type, __u64 addr, __u64 len) +{ + struct perf_event_attr attr; + + perf_event_attr_set(&attr, type, addr, len, 0); + return syscall(__NR_perf_event_open, &attr, -1, cpu, -1, 0); +} + +static void close_fds(int *fd, int n) +{ + int i; + + for (i = 0; i < n; i++) + close(fd[i]); +} + +static unsigned long read_fds(int *fd, int n) +{ + int i; + unsigned long c = 0; + unsigned long count = 0; + size_t res; + + for (i = 0; i < n; i++) { + res = read(fd[i], &c, sizeof(c)); + assert(res == sizeof(unsigned long long)); + count += c; + } + return count; +} + +static void reset_fds(int *fd, int n) +{ + int i; + + for (i = 0; i < n; i++) + ioctl(fd[i], PERF_EVENT_IOC_RESET); +} + +static void enable_fds(int *fd, int n) +{ + int i; + + for (i = 0; i < n; i++) + ioctl(fd[i], PERF_EVENT_IOC_ENABLE); +} + +static void disable_fds(int *fd, int n) +{ + int i; + + for (i = 0; i < n; i++) + ioctl(fd[i], PERF_EVENT_IOC_DISABLE); +} + +static int perf_systemwide_event_open(int *fd, __u32 type, __u64 addr, __u64 len) +{ + int i = 0; + + /* Assume online processors are 0 to nprocs for simplisity */ + for (i = 0; i < nprocs; i++) { + fd[i] = perf_cpu_event_open(i, type, addr, len); + if (fd[i] < 0) { + close_fds(fd, i); + return fd[i]; + } + } + return 0; +} + static inline bool breakpoint_test(int len) { int fd; @@ -262,11 +343,467 @@ static int runtest_dar_outside(void) return fail; }
+static void multi_dawr_workload(void) +{ + a += 10; + b += 10; + c[512 + 1] += 'a'; +} + +static int test_process_multi_diff_addr(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int fd1, fd2; + char *desc = "Process specific, Two events, diff addr"; + size_t res; + + fd1 = perf_process_event_open(HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (fd1 < 0) { + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + fd2 = perf_process_event_open(HW_BREAKPOINT_RW, (__u64)&b, (__u64)sizeof(b)); + if (fd2 < 0) { + close(fd1); + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + ioctl(fd1, PERF_EVENT_IOC_RESET); + ioctl(fd2, PERF_EVENT_IOC_RESET); + ioctl(fd1, PERF_EVENT_IOC_ENABLE); + ioctl(fd2, PERF_EVENT_IOC_ENABLE); + multi_dawr_workload(); + ioctl(fd1, PERF_EVENT_IOC_DISABLE); + ioctl(fd2, PERF_EVENT_IOC_DISABLE); + + res = read(fd1, &breaks1, sizeof(breaks1)); + assert(res == sizeof(unsigned long long)); + res = read(fd2, &breaks2, sizeof(breaks2)); + assert(res == sizeof(unsigned long long)); + + close(fd1); + close(fd2); + + if (breaks1 != 2 || breaks2 != 2) { + printf("FAILED: %s: %lld != 2 || %lld != 2\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_process_multi_same_addr(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int fd1, fd2; + char *desc = "Process specific, Two events, same addr"; + size_t res; + + fd1 = perf_process_event_open(HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (fd1 < 0) { + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + fd2 = perf_process_event_open(HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (fd2 < 0) { + close(fd1); + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + ioctl(fd1, PERF_EVENT_IOC_RESET); + ioctl(fd2, PERF_EVENT_IOC_RESET); + ioctl(fd1, PERF_EVENT_IOC_ENABLE); + ioctl(fd2, PERF_EVENT_IOC_ENABLE); + multi_dawr_workload(); + ioctl(fd1, PERF_EVENT_IOC_DISABLE); + ioctl(fd2, PERF_EVENT_IOC_DISABLE); + + res = read(fd1, &breaks1, sizeof(breaks1)); + assert(res == sizeof(unsigned long long)); + res = read(fd2, &breaks2, sizeof(breaks2)); + assert(res == sizeof(unsigned long long)); + + close(fd1); + close(fd2); + + if (breaks1 != 2 || breaks2 != 2) { + printf("FAILED: %s: %lld != 2 || %lld != 2\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_process_multi_diff_addr_ro_wo(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int fd1, fd2; + char *desc = "Process specific, Two events, diff addr, one is RO, other is WO"; + size_t res; + + fd1 = perf_process_event_open(HW_BREAKPOINT_W, (__u64)&a, (__u64)sizeof(a)); + if (fd1 < 0) { + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + fd2 = perf_process_event_open(HW_BREAKPOINT_R, (__u64)&b, (__u64)sizeof(b)); + if (fd2 < 0) { + close(fd1); + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + ioctl(fd1, PERF_EVENT_IOC_RESET); + ioctl(fd2, PERF_EVENT_IOC_RESET); + ioctl(fd1, PERF_EVENT_IOC_ENABLE); + ioctl(fd2, PERF_EVENT_IOC_ENABLE); + multi_dawr_workload(); + ioctl(fd1, PERF_EVENT_IOC_DISABLE); + ioctl(fd2, PERF_EVENT_IOC_DISABLE); + + res = read(fd1, &breaks1, sizeof(breaks1)); + assert(res == sizeof(unsigned long long)); + res = read(fd2, &breaks2, sizeof(breaks2)); + assert(res == sizeof(unsigned long long)); + + close(fd1); + close(fd2); + + if (breaks1 != 1 || breaks2 != 1) { + printf("FAILED: %s: %lld != 1 || %lld != 1\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_process_multi_same_addr_ro_wo(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int fd1, fd2; + char *desc = "Process specific, Two events, same addr, one is RO, other is WO"; + size_t res; + + fd1 = perf_process_event_open(HW_BREAKPOINT_R, (__u64)&a, (__u64)sizeof(a)); + if (fd1 < 0) { + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + fd2 = perf_process_event_open(HW_BREAKPOINT_W, (__u64)&a, (__u64)sizeof(a)); + if (fd2 < 0) { + close(fd1); + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + ioctl(fd1, PERF_EVENT_IOC_RESET); + ioctl(fd2, PERF_EVENT_IOC_RESET); + ioctl(fd1, PERF_EVENT_IOC_ENABLE); + ioctl(fd2, PERF_EVENT_IOC_ENABLE); + multi_dawr_workload(); + ioctl(fd1, PERF_EVENT_IOC_DISABLE); + ioctl(fd2, PERF_EVENT_IOC_DISABLE); + + res = read(fd1, &breaks1, sizeof(breaks1)); + assert(res == sizeof(unsigned long long)); + res = read(fd2, &breaks2, sizeof(breaks2)); + assert(res == sizeof(unsigned long long)); + + close(fd1); + close(fd2); + + if (breaks1 != 1 || breaks2 != 1) { + printf("FAILED: %s: %lld != 1 || %lld != 1\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_syswide_multi_diff_addr(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int *fd1 = malloc(nprocs * sizeof(int)); + int *fd2 = malloc(nprocs * sizeof(int)); + char *desc = "Systemwide, Two events, diff addr"; + int ret; + + ret = perf_systemwide_event_open(fd1, HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + ret = perf_systemwide_event_open(fd2, HW_BREAKPOINT_RW, (__u64)&b, (__u64)sizeof(b)); + if (ret) { + close_fds(fd1, nprocs); + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + reset_fds(fd1, nprocs); + reset_fds(fd2, nprocs); + enable_fds(fd1, nprocs); + enable_fds(fd2, nprocs); + multi_dawr_workload(); + disable_fds(fd1, nprocs); + disable_fds(fd2, nprocs); + + breaks1 = read_fds(fd1, nprocs); + breaks2 = read_fds(fd2, nprocs); + + close_fds(fd1, nprocs); + close_fds(fd2, nprocs); + + free(fd1); + free(fd2); + + if (breaks1 != 2 || breaks2 != 2) { + printf("FAILED: %s: %lld != 2 || %lld != 2\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_syswide_multi_same_addr(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int *fd1 = malloc(nprocs * sizeof(int)); + int *fd2 = malloc(nprocs * sizeof(int)); + char *desc = "Systemwide, Two events, same addr"; + int ret; + + ret = perf_systemwide_event_open(fd1, HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + ret = perf_systemwide_event_open(fd2, HW_BREAKPOINT_RW, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + close_fds(fd1, nprocs); + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + reset_fds(fd1, nprocs); + reset_fds(fd2, nprocs); + enable_fds(fd1, nprocs); + enable_fds(fd2, nprocs); + multi_dawr_workload(); + disable_fds(fd1, nprocs); + disable_fds(fd2, nprocs); + + breaks1 = read_fds(fd1, nprocs); + breaks2 = read_fds(fd2, nprocs); + + close_fds(fd1, nprocs); + close_fds(fd2, nprocs); + + free(fd1); + free(fd2); + + if (breaks1 != 2 || breaks2 != 2) { + printf("FAILED: %s: %lld != 2 || %lld != 2\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_syswide_multi_diff_addr_ro_wo(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int *fd1 = malloc(nprocs * sizeof(int)); + int *fd2 = malloc(nprocs * sizeof(int)); + char *desc = "Systemwide, Two events, diff addr, one is RO, other is WO"; + int ret; + + ret = perf_systemwide_event_open(fd1, HW_BREAKPOINT_W, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + ret = perf_systemwide_event_open(fd2, HW_BREAKPOINT_R, (__u64)&b, (__u64)sizeof(b)); + if (ret) { + close_fds(fd1, nprocs); + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + reset_fds(fd1, nprocs); + reset_fds(fd2, nprocs); + enable_fds(fd1, nprocs); + enable_fds(fd2, nprocs); + multi_dawr_workload(); + disable_fds(fd1, nprocs); + disable_fds(fd2, nprocs); + + breaks1 = read_fds(fd1, nprocs); + breaks2 = read_fds(fd2, nprocs); + + close_fds(fd1, nprocs); + close_fds(fd2, nprocs); + + free(fd1); + free(fd2); + + if (breaks1 != 1 || breaks2 != 1) { + printf("FAILED: %s: %lld != 1 || %lld != 1\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int test_syswide_multi_same_addr_ro_wo(void) +{ + unsigned long long breaks1 = 0, breaks2 = 0; + int *fd1 = malloc(nprocs * sizeof(int)); + int *fd2 = malloc(nprocs * sizeof(int)); + char *desc = "Systemwide, Two events, same addr, one is RO, other is WO"; + int ret; + + ret = perf_systemwide_event_open(fd1, HW_BREAKPOINT_W, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + ret = perf_systemwide_event_open(fd2, HW_BREAKPOINT_R, (__u64)&a, (__u64)sizeof(a)); + if (ret) { + close_fds(fd1, nprocs); + perror("perf_systemwide_event_open"); + exit(EXIT_FAILURE); + } + + reset_fds(fd1, nprocs); + reset_fds(fd2, nprocs); + enable_fds(fd1, nprocs); + enable_fds(fd2, nprocs); + multi_dawr_workload(); + disable_fds(fd1, nprocs); + disable_fds(fd2, nprocs); + + breaks1 = read_fds(fd1, nprocs); + breaks2 = read_fds(fd2, nprocs); + + close_fds(fd1, nprocs); + close_fds(fd2, nprocs); + + free(fd1); + free(fd2); + + if (breaks1 != 1 || breaks2 != 1) { + printf("FAILED: %s: %lld != 1 || %lld != 1\n", desc, breaks1, breaks2); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +static int runtest_multi_dawr(void) +{ + int ret = 0; + + ret |= test_process_multi_diff_addr(); + ret |= test_process_multi_same_addr(); + ret |= test_process_multi_diff_addr_ro_wo(); + ret |= test_process_multi_same_addr_ro_wo(); + ret |= test_syswide_multi_diff_addr(); + ret |= test_syswide_multi_same_addr(); + ret |= test_syswide_multi_diff_addr_ro_wo(); + ret |= test_syswide_multi_same_addr_ro_wo(); + + return ret; +} + +static int runtest_unaligned_512bytes(void) +{ + unsigned long long breaks = 0; + int fd; + char *desc = "Process specific, 512 bytes, unaligned"; + __u64 addr = (__u64)&c + 8; + size_t res; + + fd = perf_process_event_open(HW_BREAKPOINT_RW, addr, 512); + if (fd < 0) { + perror("perf_process_event_open"); + exit(EXIT_FAILURE); + } + + ioctl(fd, PERF_EVENT_IOC_RESET); + ioctl(fd, PERF_EVENT_IOC_ENABLE); + multi_dawr_workload(); + ioctl(fd, PERF_EVENT_IOC_DISABLE); + + res = read(fd, &breaks, sizeof(breaks)); + assert(res == sizeof(unsigned long long)); + + close(fd); + + if (breaks != 2) { + printf("FAILED: %s: %lld != 2\n", desc, breaks); + return 1; + } + + printf("TESTED: %s\n", desc); + return 0; +} + +/* There is no perf api to find number of available watchpoints. Use ptrace. */ +static int get_nr_wps(bool *arch_31) +{ + struct ppc_debug_info dbginfo; + int child_pid; + + child_pid = fork(); + if (!child_pid) { + int ret = ptrace(PTRACE_TRACEME, 0, NULL, 0); + if (ret) { + perror("PTRACE_TRACEME failed\n"); + exit(EXIT_FAILURE); + } + kill(getpid(), SIGUSR1); + + sleep(1); + exit(EXIT_SUCCESS); + } + + wait(NULL); + if (ptrace(PPC_PTRACE_GETHWDBGINFO, child_pid, NULL, &dbginfo)) { + perror("Can't get breakpoint info"); + exit(EXIT_FAILURE); + } + + *arch_31 = !!(dbginfo.features & PPC_DEBUG_FEATURE_DATA_BP_ARCH_31); + return dbginfo.num_data_bps; +} + static int runtest(void) { int rwflag; int exclude_user; int ret; + bool dawr = dawr_supported(); + bool arch_31 = false; + int nr_wps = get_nr_wps(&arch_31);
/* * perf defines rwflag as two bits read and write and at least @@ -279,7 +816,7 @@ static int runtest(void) return ret;
/* if we have the dawr, we can do an array test */ - if (!dawr_supported()) + if (!dawr) continue; ret = runtestsingle(rwflag, exclude_user, 1); if (ret) @@ -288,6 +825,19 @@ static int runtest(void) }
ret = runtest_dar_outside(); + if (ret) + return ret; + + if (dawr && nr_wps > 1) { + nprocs = get_nprocs(); + ret = runtest_multi_dawr(); + if (ret) + return ret; + } + + if (dawr && arch_31) + ret = runtest_unaligned_512bytes(); + return ret; }
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"); +}
On Mon, 12 Apr 2021 16:52:14 +0530, Ravi Bangoria wrote:
Power10 introduced 2nd watchpoint (DAWR). ISA 3.1, Book 3S, Ch 9 - 'Debug Facilities' covers the feature in detail. Kernel patches to enable the 2nd DAWR are already in[1], including kvm enablement[2]. These patches adds selftests for 2nd DAWR.
[...]
Applied to powerpc/next.
[1/4] powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR https://git.kernel.org/powerpc/c/dae4ff8031b49af4721101d6298fc14cb9c16a4c [2/4] powerpc/selftests/perf-hwbreak: Coalesce event creation code https://git.kernel.org/powerpc/c/c9cb0afb4eaa03801322f48dad4093979ff45e88 [3/4] powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR https://git.kernel.org/powerpc/c/c65c64cc7bbd273121edf96a7a5a0269038ab454 [4/4] powerpc/selftests: Add selftest to test concurrent perf/ptrace events https://git.kernel.org/powerpc/c/290f7d8ce2b1eea5413bb120e0d9d610675b7fba
cheers
linux-kselftest-mirror@lists.linaro.org
-
Michael Ellerman -
Ravi Bangoria