4 files changed, 416 insertions, 2 deletions

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 298a5c0c1ead..4ec84018cc13 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 000000000000..f362722cdce7
--- /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 000000000000..a0743f3b2b57
--- /dev/null
+++ b/tools/testing/selftests/breakpoints/breakpoint_test.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftests for breakpoints (and more generally the do_debug() path) in x86.
+ */
+
+
+#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>
+
+
+/* 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 701960d9e531..320718a4e6bf 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