From: Michael Neuling mikey@neuling.org
[ Upstream commit 9c2ddfe55c42bf4b9bc336a0650ab78f9222a159 ]
This test the ptrace hw breakpoints via PTRACE_SET_DEBUGREG and PPC_PTRACE_SETHWDEBUG. This test was use to find the bugs fixed by these recent commits:
4f7c06e26e powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG cd6ef7eebf powerpc/ptrace: Fix enforcement of DAWR constraints
Signed-off-by: Michael Neuling mikey@neuling.org [mpe: Add SPDX tag, clang format it] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Sasha Levin sashal@kernel.org --- .../selftests/powerpc/ptrace/.gitignore | 1 + .../testing/selftests/powerpc/ptrace/Makefile | 2 +- .../selftests/powerpc/ptrace/ptrace-hwbreak.c | 342 ++++++++++++++++++ 3 files changed, 344 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
diff --git a/tools/testing/selftests/powerpc/ptrace/.gitignore b/tools/testing/selftests/powerpc/ptrace/.gitignore index 349acfafc95b..9dcc16ea8179 100644 --- a/tools/testing/selftests/powerpc/ptrace/.gitignore +++ b/tools/testing/selftests/powerpc/ptrace/.gitignore @@ -8,3 +8,4 @@ ptrace-vsx ptrace-tm-vsx ptrace-tm-spd-vsx ptrace-tm-spr +ptrace-hwbreak diff --git a/tools/testing/selftests/powerpc/ptrace/Makefile b/tools/testing/selftests/powerpc/ptrace/Makefile index 480305266504..0e2f4601d1a8 100644 --- a/tools/testing/selftests/powerpc/ptrace/Makefile +++ b/tools/testing/selftests/powerpc/ptrace/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 TEST_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-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak
include ../../lib.mk
diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c new file mode 100644 index 000000000000..3066d310f32b --- /dev/null +++ b/tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0+ + +/* + * Ptrace test for hw breakpoints + * + * Based on tools/testing/selftests/breakpoints/breakpoint_test.c + * + * This test forks and the parent then traces the child doing various + * types of ptrace enabled breakpoints + * + * Copyright (C) 2018 Michael Neuling, IBM Corporation. + */ + +#include <sys/ptrace.h> +#include <unistd.h> +#include <stddef.h> +#include <sys/user.h> +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/wait.h> +#include "ptrace.h" + +/* Breakpoint access modes */ +enum { + BP_X = 1, + BP_RW = 2, + BP_W = 4, +}; + +static pid_t child_pid; +static struct ppc_debug_info dbginfo; + +static void get_dbginfo(void) +{ + int ret; + + ret = ptrace(PPC_PTRACE_GETHWDBGINFO, child_pid, NULL, &dbginfo); + if (ret) { + perror("Can't get breakpoint info\n"); + exit(-1); + } +} + +static bool hwbreak_present(void) +{ + return (dbginfo.num_data_bps != 0); +} + +static bool dawr_present(void) +{ + return !!(dbginfo.features & PPC_DEBUG_FEATURE_DATA_BP_DAWR); +} + +static void set_breakpoint_addr(void *addr) +{ + int ret; + + ret = ptrace(PTRACE_SET_DEBUGREG, child_pid, 0, addr); + if (ret) { + perror("Can't set breakpoint addr\n"); + exit(-1); + } +} + +static int set_hwbreakpoint_addr(void *addr, int range) +{ + int ret; + + struct ppc_hw_breakpoint info; + + info.version = 1; + info.trigger_type = PPC_BREAKPOINT_TRIGGER_RW; + info.addr_mode = PPC_BREAKPOINT_MODE_EXACT; + if (range > 0) + info.addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE; + info.condition_mode = PPC_BREAKPOINT_CONDITION_NONE; + info.addr = (__u64)addr; + info.addr2 = (__u64)addr + range; + info.condition_value = 0; + + ret = ptrace(PPC_PTRACE_SETHWDEBUG, child_pid, 0, &info); + if (ret < 0) { + perror("Can't set breakpoint\n"); + exit(-1); + } + return ret; +} + +static int del_hwbreakpoint_addr(int watchpoint_handle) +{ + int ret; + + ret = ptrace(PPC_PTRACE_DELHWDEBUG, child_pid, 0, watchpoint_handle); + if (ret < 0) { + perror("Can't delete hw breakpoint\n"); + exit(-1); + } + return ret; +} + +#define DAWR_LENGTH_MAX 512 + +/* Dummy variables to test read/write accesses */ +static unsigned long long + dummy_array[DAWR_LENGTH_MAX / sizeof(unsigned long long)] + __attribute__((aligned(512))); +static unsigned long long *dummy_var = dummy_array; + +static void write_var(int len) +{ + long long *plval; + char *pcval; + short *psval; + int *pival; + + switch (len) { + case 1: + pcval = (char *)dummy_var; + *pcval = 0xff; + break; + case 2: + psval = (short *)dummy_var; + *psval = 0xffff; + break; + case 4: + pival = (int *)dummy_var; + *pival = 0xffffffff; + break; + case 8: + plval = (long long *)dummy_var; + *plval = 0xffffffffffffffffLL; + break; + } +} + +static void read_var(int len) +{ + char cval __attribute__((unused)); + short sval __attribute__((unused)); + int ival __attribute__((unused)); + long long lval __attribute__((unused)); + + switch (len) { + case 1: + cval = *(char *)dummy_var; + break; + case 2: + sval = *(short *)dummy_var; + break; + case 4: + ival = *(int *)dummy_var; + break; + case 8: + lval = *(long long *)dummy_var; + break; + } +} + +/* + * Do the r/w accesses to trigger the breakpoints. And run + * the usual traps. + */ +static void trigger_tests(void) +{ + int len, ret; + + ret = ptrace(PTRACE_TRACEME, 0, NULL, 0); + if (ret) { + perror("Can't be traced?\n"); + return; + } + + /* Wake up father so that it sets up the first test */ + kill(getpid(), SIGUSR1); + + /* Test write watchpoints */ + for (len = 1; len <= sizeof(long); len <<= 1) + write_var(len); + + /* Test read/write watchpoints (on read accesses) */ + for (len = 1; len <= sizeof(long); len <<= 1) + read_var(len); + + /* Test when breakpoint is unset */ + + /* Test write watchpoints */ + for (len = 1; len <= sizeof(long); len <<= 1) + write_var(len); + + /* Test read/write watchpoints (on read accesses) */ + for (len = 1; len <= sizeof(long); len <<= 1) + read_var(len); +} + +static void check_success(const char *msg) +{ + const char *msg2; + int status; + + /* Wait for the child to SIGTRAP */ + wait(&status); + + msg2 = "Failed"; + + if (WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP) { + msg2 = "Child process hit the breakpoint"; + } + + printf("%s Result: [%s]\n", msg, msg2); +} + +static void launch_watchpoints(char *buf, int mode, int len, + struct ppc_debug_info *dbginfo, bool dawr) +{ + const char *mode_str; + unsigned long data = (unsigned long)(dummy_var); + int wh, range; + + data &= ~0x7UL; + + if (mode == BP_W) { + data |= (1UL << 1); + mode_str = "write"; + } else { + data |= (1UL << 0); + data |= (1UL << 1); + mode_str = "read"; + } + + /* Set DABR_TRANSLATION bit */ + data |= (1UL << 2); + + /* use PTRACE_SET_DEBUGREG breakpoints */ + set_breakpoint_addr((void *)data); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + sprintf(buf, "Test %s watchpoint with len: %d ", mode_str, len); + check_success(buf); + /* Unregister hw brkpoint */ + set_breakpoint_addr(NULL); + + data = (data & ~7); /* remove dabr control bits */ + + /* use PPC_PTRACE_SETHWDEBUG breakpoint */ + if (!(dbginfo->features & PPC_DEBUG_FEATURE_DATA_BP_RANGE)) + return; /* not supported */ + wh = set_hwbreakpoint_addr((void *)data, 0); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + sprintf(buf, "Test %s watchpoint with len: %d ", mode_str, len); + check_success(buf); + /* Unregister hw brkpoint */ + del_hwbreakpoint_addr(wh); + + /* try a wider range */ + range = 8; + if (dawr) + range = 512 - ((int)data & (DAWR_LENGTH_MAX - 1)); + wh = set_hwbreakpoint_addr((void *)data, range); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + sprintf(buf, "Test %s watchpoint with len: %d ", mode_str, len); + check_success(buf); + /* Unregister hw brkpoint */ + del_hwbreakpoint_addr(wh); +} + +/* Set the breakpoints and check the child successfully trigger them */ +static int launch_tests(bool dawr) +{ + char buf[1024]; + int len, i, status; + + struct ppc_debug_info dbginfo; + + i = ptrace(PPC_PTRACE_GETHWDBGINFO, child_pid, NULL, &dbginfo); + if (i) { + perror("Can't set breakpoint info\n"); + exit(-1); + } + if (!(dbginfo.features & PPC_DEBUG_FEATURE_DATA_BP_RANGE)) + printf("WARNING: Kernel doesn't support PPC_PTRACE_SETHWDEBUG\n"); + + /* Write watchpoint */ + for (len = 1; len <= sizeof(long); len <<= 1) + launch_watchpoints(buf, BP_W, len, &dbginfo, dawr); + + /* Read-Write watchpoint */ + for (len = 1; len <= sizeof(long); len <<= 1) + launch_watchpoints(buf, BP_RW, len, &dbginfo, dawr); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); + + /* + * Now we have unregistered the breakpoint, access by child + * should not cause SIGTRAP. + */ + + wait(&status); + + if (WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP) { + printf("FAIL: Child process hit the breakpoint, which is not expected\n"); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + return TEST_FAIL; + } + + if (WIFEXITED(status)) + printf("Child exited normally\n"); + + return TEST_PASS; +} + +static int ptrace_hwbreak(void) +{ + pid_t pid; + int ret; + bool dawr; + + pid = fork(); + if (!pid) { + trigger_tests(); + return 0; + } + + wait(NULL); + + child_pid = pid; + + get_dbginfo(); + SKIP_IF(!hwbreak_present()); + dawr = dawr_present(); + + ret = launch_tests(dawr); + + wait(NULL); + + return ret; +} + +int main(int argc, char **argv, char **envp) +{ + return test_harness(ptrace_hwbreak, "ptrace-hwbreak"); +}