From 274343ad3e63c4dcee6744a75b5553940de4a0f6 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 12 Jan 2012 17:20:44 -0800 Subject: selftests: new very basic kernel selftests directory Bring a new kernel selftests directory in tools/testing/selftests. To add a new selftest, create a subdirectory with the sources and a makefile that creates a target named "run_test" then add the subdirectory name to the TARGET var in tools/testing/selftests/Makefile and tools/testing/selftests/run_tests script. This can help centralizing and maintaining any useful selftest that developers usually tend to let rust in peace on some random server. Suggested-by: Andrew Morton Signed-off-by: Frederic Weisbecker Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Jason Wessel Cc: Will Deacon Cc: Steven Rostedt Cc: Michal Marek Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/Makefile | 11 +++++++++++ tools/testing/selftests/run_tests | 8 ++++++++ 2 files changed, 19 insertions(+) create mode 100644 tools/testing/selftests/Makefile create mode 100644 tools/testing/selftests/run_tests (limited to 'tools') diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile new file mode 100644 index 00000000000..298a5c0c1ea --- /dev/null +++ b/tools/testing/selftests/Makefile @@ -0,0 +1,11 @@ +TARGETS = + +all: + for TARGET in $(TARGETS); do \ + make -C $$TARGET; \ + done; + +clean: + for TARGET in $(TARGETS); do \ + make -C $$TARGET clean; \ + done; diff --git a/tools/testing/selftests/run_tests b/tools/testing/selftests/run_tests new file mode 100644 index 00000000000..701960d9e53 --- /dev/null +++ b/tools/testing/selftests/run_tests @@ -0,0 +1,8 @@ +#!/bin/bash + +TARGETS= + +for TARGET in $TARGETS +do + $TARGET/run_test +done -- cgit v1.2.3 From 85bbddc37b2bf947a577d572b1c4c23bf829217f Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 12 Jan 2012 17:20:46 -0800 Subject: selftests: new x86 breakpoints selftest Bring a first selftest in the relevant directory. This tests several combinations of breakpoints and watchpoints in x86, as well as icebp traps and int3 traps. Given the amount of breakpoint regressions we raised after we merged the generic breakpoint infrastructure, such selftest became necessary and can still serve today as a basis for new patches that touch the do_debug() path. Signed-off-by: Frederic Weisbecker Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Cc: Jason Wessel Cc: Will Deacon Cc: Michal Marek Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/Makefile | 2 +- tools/testing/selftests/breakpoints/Makefile | 20 ++ .../selftests/breakpoints/breakpoint_test.c | 394 +++++++++++++++++++++ tools/testing/selftests/run_tests | 2 +- 4 files changed, 416 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/breakpoints/Makefile create mode 100644 tools/testing/selftests/breakpoints/breakpoint_test.c (limited to 'tools') diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 298a5c0c1ea..4ec84018cc1 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -1,4 +1,4 @@ -TARGETS = +TARGETS = breakpoints all: for TARGET in $(TARGETS); do \ diff --git a/tools/testing/selftests/breakpoints/Makefile b/tools/testing/selftests/breakpoints/Makefile new file mode 100644 index 00000000000..f362722cdce --- /dev/null +++ b/tools/testing/selftests/breakpoints/Makefile @@ -0,0 +1,20 @@ +# Taken from perf makefile +uname_M := $(shell uname -m 2>/dev/null || echo not) +ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/) +ifeq ($(ARCH),i386) + ARCH := x86 +endif +ifeq ($(ARCH),x86_64) + ARCH := x86 +endif + + +all: +ifeq ($(ARCH),x86) + gcc breakpoint_test.c -o run_test +else + echo "Not an x86 target, can't build breakpoints selftests" +endif + +clean: + rm -fr run_test diff --git a/tools/testing/selftests/breakpoints/breakpoint_test.c b/tools/testing/selftests/breakpoints/breakpoint_test.c new file mode 100644 index 00000000000..a0743f3b2b5 --- /dev/null +++ b/tools/testing/selftests/breakpoints/breakpoint_test.c @@ -0,0 +1,394 @@ +/* + * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker + * + * Licensed under the terms of the GNU GPL License version 2 + * + * Selftests for breakpoints (and more generally the do_debug() path) in x86. + */ + + +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* Breakpoint access modes */ +enum { + BP_X = 1, + BP_RW = 2, + BP_W = 4, +}; + +static pid_t child_pid; + +/* + * Ensures the child and parent are always "talking" about + * the same test sequence. (ie: that we haven't forgotten + * to call check_trapped() somewhere). + */ +static int nr_tests; + +static void set_breakpoint_addr(void *addr, int n) +{ + int ret; + + ret = ptrace(PTRACE_POKEUSER, child_pid, + offsetof(struct user, u_debugreg[n]), addr); + if (ret) { + perror("Can't set breakpoint addr\n"); + exit(-1); + } +} + +static void toggle_breakpoint(int n, int type, int len, + int local, int global, int set) +{ + int ret; + + int xtype, xlen; + unsigned long vdr7, dr7; + + switch (type) { + case BP_X: + xtype = 0; + break; + case BP_W: + xtype = 1; + break; + case BP_RW: + xtype = 3; + break; + } + + switch (len) { + case 1: + xlen = 0; + break; + case 2: + xlen = 4; + break; + case 4: + xlen = 0xc; + break; + case 8: + xlen = 8; + break; + } + + dr7 = ptrace(PTRACE_PEEKUSER, child_pid, + offsetof(struct user, u_debugreg[7]), 0); + + vdr7 = (xlen | xtype) << 16; + vdr7 <<= 4 * n; + + if (local) { + vdr7 |= 1 << (2 * n); + vdr7 |= 1 << 8; + } + if (global) { + vdr7 |= 2 << (2 * n); + vdr7 |= 1 << 9; + } + + if (set) + dr7 |= vdr7; + else + dr7 &= ~vdr7; + + ret = ptrace(PTRACE_POKEUSER, child_pid, + offsetof(struct user, u_debugreg[7]), dr7); + if (ret) { + perror("Can't set dr7"); + exit(-1); + } +} + +/* Dummy variables to test read/write accesses */ +static unsigned long long dummy_var[4]; + +/* Dummy functions to test execution accesses */ +static void dummy_func(void) { } +static void dummy_func1(void) { } +static void dummy_func2(void) { } +static void dummy_func3(void) { } + +static void (*dummy_funcs[])(void) = { + dummy_func, + dummy_func1, + dummy_func2, + dummy_func3, +}; + +static int trapped; + +static void check_trapped(void) +{ + /* + * If we haven't trapped, wake up the parent + * so that it notices the failure. + */ + if (!trapped) + kill(getpid(), SIGUSR1); + trapped = 0; + + nr_tests++; +} + +static void write_var(int len) +{ + char *pcval; short *psval; int *pival; long long *plval; + int i; + + for (i = 0; i < 4; i++) { + switch (len) { + case 1: + pcval = (char *)&dummy_var[i]; + *pcval = 0xff; + break; + case 2: + psval = (short *)&dummy_var[i]; + *psval = 0xffff; + break; + case 4: + pival = (int *)&dummy_var[i]; + *pival = 0xffffffff; + break; + case 8: + plval = (long long *)&dummy_var[i]; + *plval = 0xffffffffffffffffLL; + break; + } + check_trapped(); + } +} + +static void read_var(int len) +{ + char cval; short sval; int ival; long long lval; + int i; + + for (i = 0; i < 4; i++) { + switch (len) { + case 1: + cval = *(char *)&dummy_var[i]; + break; + case 2: + sval = *(short *)&dummy_var[i]; + break; + case 4: + ival = *(int *)&dummy_var[i]; + break; + case 8: + lval = *(long long *)&dummy_var[i]; + break; + } + check_trapped(); + } +} + +/* + * Do the r/w/x accesses to trigger the breakpoints. And run + * the usual traps. + */ +static void trigger_tests(void) +{ + int len, local, global, i; + char val; + int 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 instruction breakpoints */ + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + + for (i = 0; i < 4; i++) { + dummy_funcs[i](); + check_trapped(); + } + } + } + + /* Test write watchpoints */ + for (len = 1; len <= sizeof(long); len <<= 1) { + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + write_var(len); + } + } + } + + /* Test read/write watchpoints (on read accesses) */ + for (len = 1; len <= sizeof(long); len <<= 1) { + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + read_var(len); + } + } + } + + /* Icebp trap */ + asm(".byte 0xf1\n"); + check_trapped(); + + /* Int 3 trap */ + asm("int $3\n"); + check_trapped(); + + kill(getpid(), SIGUSR1); +} + +static void check_success(const char *msg) +{ + const char *msg2; + int child_nr_tests; + int status; + + /* Wait for the child to SIGTRAP */ + wait(&status); + + msg2 = "Failed"; + + if (WSTOPSIG(status) == SIGTRAP) { + child_nr_tests = ptrace(PTRACE_PEEKDATA, child_pid, + &nr_tests, 0); + if (child_nr_tests == nr_tests) + msg2 = "Ok"; + if (ptrace(PTRACE_POKEDATA, child_pid, &trapped, 1)) { + perror("Can't poke\n"); + exit(-1); + } + } + + nr_tests++; + + printf("%s [%s]\n", msg, msg2); +} + +static void launch_instruction_breakpoints(char *buf, int local, int global) +{ + int i; + + for (i = 0; i < 4; i++) { + set_breakpoint_addr(dummy_funcs[i], i); + toggle_breakpoint(i, BP_X, 1, local, global, 1); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + sprintf(buf, "Test breakpoint %d with local: %d global: %d", + i, local, global); + check_success(buf); + toggle_breakpoint(i, BP_X, 1, local, global, 0); + } +} + +static void launch_watchpoints(char *buf, int mode, int len, + int local, int global) +{ + const char *mode_str; + int i; + + if (mode == BP_W) + mode_str = "write"; + else + mode_str = "read"; + + for (i = 0; i < 4; i++) { + set_breakpoint_addr(&dummy_var[i], i); + toggle_breakpoint(i, mode, len, local, global, 1); + ptrace(PTRACE_CONT, child_pid, NULL, 0); + sprintf(buf, "Test %s watchpoint %d with len: %d local: " + "%d global: %d", mode_str, i, len, local, global); + check_success(buf); + toggle_breakpoint(i, mode, len, local, global, 0); + } +} + +/* Set the breakpoints and check the child successfully trigger them */ +static void launch_tests(void) +{ + char buf[1024]; + int len, local, global, i; + + /* Instruction breakpoints */ + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + launch_instruction_breakpoints(buf, local, global); + } + } + + /* Write watchpoint */ + for (len = 1; len <= sizeof(long); len <<= 1) { + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + launch_watchpoints(buf, BP_W, len, + local, global); + } + } + } + + /* Read-Write watchpoint */ + for (len = 1; len <= sizeof(long); len <<= 1) { + for (local = 0; local < 2; local++) { + for (global = 0; global < 2; global++) { + if (!local && !global) + continue; + launch_watchpoints(buf, BP_RW, len, + local, global); + } + } + } + + /* Icebp traps */ + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success("Test icebp"); + + /* Int 3 traps */ + ptrace(PTRACE_CONT, child_pid, NULL, 0); + check_success("Test int 3 trap"); + + ptrace(PTRACE_CONT, child_pid, NULL, 0); +} + +int main(int argc, char **argv) +{ + pid_t pid; + int ret; + + pid = fork(); + if (!pid) { + trigger_tests(); + return 0; + } + + child_pid = pid; + + wait(NULL); + + launch_tests(); + + wait(NULL); + + return 0; +} diff --git a/tools/testing/selftests/run_tests b/tools/testing/selftests/run_tests index 701960d9e53..320718a4e6b 100644 --- a/tools/testing/selftests/run_tests +++ b/tools/testing/selftests/run_tests @@ -1,6 +1,6 @@ #!/bin/bash -TARGETS= +TARGETS=breakpoints for TARGET in $TARGETS do -- cgit v1.2.3