kgdbts.c

Go to the documentation of this file.

/*
 * kgdbts is a test suite for kgdb for the sole purpose of validating
 * that key pieces of the kgdb internals are working properly such as
 * HW/SW breakpoints, single stepping, and NMI.
 *
 * Created by: Jason Wessel <[email protected]>
 *
 * Copyright (c) 2008 Wind River Systems, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
/* Information about the kgdb test suite.
 * -------------------------------------
 *
 * The kgdb test suite is designed as a KGDB I/O module which
 * simulates the communications that a debugger would have with kgdb.
 * The tests are broken up in to a line by line and referenced here as
 * a "get" which is kgdb requesting input and "put" which is kgdb
 * sending a response.
 *
 * The kgdb suite can be invoked from the kernel command line
 * arguments system or executed dynamically at run time.  The test
 * suite uses the variable "kgdbts" to obtain the information about
 * which tests to run and to configure the verbosity level.  The
 * following are the various characters you can use with the kgdbts=
 * line:
 *
 * When using the "kgdbts=" you only choose one of the following core
 * test types:
 * A = Run all the core tests silently
 * V1 = Run all the core tests with minimal output
 * V2 = Run all the core tests in debug mode
 *
 * You can also specify optional tests:
 * N## = Go to sleep with interrupts of for ## seconds
 *       to test the HW NMI watchdog
 * F## = Break at do_fork for ## iterations
 * S## = Break at sys_open for ## iterations
 * I## = Run the single step test ## iterations
 *
 * NOTE: that the do_fork and sys_open tests are mutually exclusive.
 *
 * To invoke the kgdb test suite from boot you use a kernel start
 * argument as follows:
 *  kgdbts=V1 kgdbwait
 * Or if you wanted to perform the NMI test for 6 seconds and do_fork
 * test for 100 forks, you could use:
 *  kgdbts=V1N6F100 kgdbwait
 *
 * The test suite can also be invoked at run time with:
 *  echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
 * Or as another example:
 *  echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts
 *
 * When developing a new kgdb arch specific implementation or
 * using these tests for the purpose of regression testing,
 * several invocations are required.
 *
 * 1) Boot with the test suite enabled by using the kernel arguments
 *       "kgdbts=V1F100 kgdbwait"
 *    ## If kgdb arch specific implementation has NMI use
 *       "kgdbts=V1N6F100
 *
 * 2) After the system boot run the basic test.
 * echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts
 *
 * 3) Run the concurrency tests.  It is best to use n+1
 *    while loops where n is the number of cpus you have
 *    in your system.  The example below uses only two
 *    loops.
 *
 * ## This tests break points on sys_open
 * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
 * while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
 * echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
 * fg # and hit control-c
 * fg # and hit control-c
 * ## This tests break points on do_fork
 * while [ 1 ] ; do date > /dev/null ; done &
 * while [ 1 ] ; do date > /dev/null ; done &
 * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
 * fg # and hit control-c
 *
 */

#include <linux/kernel.h>
#include <linux/kgdb.h>
#include <linux/ctype.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/nmi.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/module.h>

#define v1printk(a...) do { \
    if (verbose) \
        printk(KERN_INFO a); \
    } while (0)
#define v2printk(a...) do { \
    if (verbose > 1) \
        printk(KERN_INFO a); \
        touch_nmi_watchdog();   \
    } while (0)
#define eprintk(a...) do { \
        printk(KERN_ERR a); \
        WARN_ON(1); \
    } while (0)
#define MAX_CONFIG_LEN      40

static struct kgdb_io kgdbts_io_ops;
static char get_buf[BUFMAX];
static int get_buf_cnt;
static char put_buf[BUFMAX];
static int put_buf_cnt;
static char scratch_buf[BUFMAX];
static int verbose;
static int repeat_test;
static int test_complete;
static int send_ack;
static int final_ack;
static int force_hwbrks;
static int hwbreaks_ok;
static int hw_break_val;
static int hw_break_val2;
static int cont_instead_of_sstep;
static unsigned long cont_thread_id;
static unsigned long sstep_thread_id;
#if defined(CONFIG_ARM) || defined(CONFIG_MIPS) || defined(CONFIG_SPARC)
static int arch_needs_sstep_emulation = 1;
#else
static int arch_needs_sstep_emulation;
#endif
static unsigned long cont_addr;
static unsigned long sstep_addr;
static int restart_from_top_after_write;
static int sstep_state;

/* Storage for the registers, in GDB format. */
static unsigned long kgdbts_gdb_regs[(NUMREGBYTES +
                    sizeof(unsigned long) - 1) /
                    sizeof(unsigned long)];
static struct pt_regs kgdbts_regs;

/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
static int configured       = -1;

#ifdef CONFIG_KGDB_TESTS_BOOT_STRING
static char config[MAX_CONFIG_LEN] = CONFIG_KGDB_TESTS_BOOT_STRING;
#else
static char config[MAX_CONFIG_LEN];
#endif
static struct kparam_string kps = {
    .string         = config,
    .maxlen         = MAX_CONFIG_LEN,
};

static void fill_get_buf(char *buf);

struct test_struct {
    char *get;
    char *put;
    void (*get_handler)(char *);
    int (*put_handler)(char *, char *);
};

struct test_state {
    char *name;
    struct test_struct *tst;
    int idx;
    int (*run_test) (int, int);
    int (*validate_put) (char *);
};

static struct test_state ts;

static int kgdbts_unreg_thread(void *ptr)
{
    /* Wait until the tests are complete and then ungresiter the I/O
     * driver.
     */
    while (!final_ack)
        msleep_interruptible(1500);
    /* Pause for any other threads to exit after final ack. */
    msleep_interruptible(1000);
    if (configured)
        kgdb_unregister_io_module(&kgdbts_io_ops);
    configured = 0;

    return 0;
}

/* This is noinline such that it can be used for a single location to
 * place a breakpoint
 */
static noinline void kgdbts_break_test(void)
{
    v2printk("kgdbts: breakpoint complete\n");
}

/* Lookup symbol info in the kernel */
static unsigned long lookup_addr(char *arg)
{
    unsigned long addr = 0;

    if (!strcmp(arg, "kgdbts_break_test"))
        addr = (unsigned long)kgdbts_break_test;
    else if (!strcmp(arg, "sys_open"))
        addr = (unsigned long)do_sys_open;
    else if (!strcmp(arg, "do_fork"))
        addr = (unsigned long)do_fork;
    else if (!strcmp(arg, "hw_break_val"))
        addr = (unsigned long)&hw_break_val;
    return addr;
}

static void break_helper(char *bp_type, char *arg, unsigned long vaddr)
{
    unsigned long addr;

    if (arg)
        addr = lookup_addr(arg);
    else
        addr = vaddr;

    sprintf(scratch_buf, "%s,%lx,%i", bp_type, addr,
        BREAK_INSTR_SIZE);
    fill_get_buf(scratch_buf);
}

static void sw_break(char *arg)
{
    break_helper(force_hwbrks ? "Z1" : "Z0", arg, 0);
}

static void sw_rem_break(char *arg)
{
    break_helper(force_hwbrks ? "z1" : "z0", arg, 0);
}

static void hw_break(char *arg)
{
    break_helper("Z1", arg, 0);
}

static void hw_rem_break(char *arg)
{
    break_helper("z1", arg, 0);
}

static void hw_write_break(char *arg)
{
    break_helper("Z2", arg, 0);
}

static void hw_rem_write_break(char *arg)
{
    break_helper("z2", arg, 0);
}

static void hw_access_break(char *arg)
{
    break_helper("Z4", arg, 0);
}

static void hw_rem_access_break(char *arg)
{
    break_helper("z4", arg, 0);
}

static void hw_break_val_access(void)
{
    hw_break_val2 = hw_break_val;
}

static void hw_break_val_write(void)
{
    hw_break_val++;
}

static int get_thread_id_continue(char *put_str, char *arg)
{
    char *ptr = &put_str[11];

    if (put_str[1] != 'T' || put_str[2] != '0')
        return 1;
    kgdb_hex2long(&ptr, &cont_thread_id);
    return 0;
}

static int check_and_rewind_pc(char *put_str, char *arg)
{
    unsigned long addr = lookup_addr(arg);
    unsigned long ip;
    int offset = 0;

    kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
         NUMREGBYTES);
    gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
    ip = instruction_pointer(&kgdbts_regs);
    v2printk("Stopped at IP: %lx\n", ip);
#ifdef GDB_ADJUSTS_BREAK_OFFSET
    /* On some arches, a breakpoint stop requires it to be decremented */
    if (addr + BREAK_INSTR_SIZE == ip)
        offset = -BREAK_INSTR_SIZE;
#endif

    if (arch_needs_sstep_emulation && sstep_addr &&
        ip + offset == sstep_addr &&
        ((!strcmp(arg, "sys_open") || !strcmp(arg, "do_fork")))) {
        /* This is special case for emulated single step */
        v2printk("Emul: rewind hit single step bp\n");
        restart_from_top_after_write = 1;
    } else if (strcmp(arg, "silent") && ip + offset != addr) {
        eprintk("kgdbts: BP mismatch %lx expected %lx\n",
               ip + offset, addr);
        return 1;
    }
    /* Readjust the instruction pointer if needed */
    ip += offset;
    cont_addr = ip;
#ifdef GDB_ADJUSTS_BREAK_OFFSET
    instruction_pointer_set(&kgdbts_regs, ip);
#endif
    return 0;
}

static int check_single_step(char *put_str, char *arg)
{
    unsigned long addr = lookup_addr(arg);
    static int matched_id;

    /*
     * From an arch indepent point of view the instruction pointer
     * should be on a different instruction
     */
    kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
         NUMREGBYTES);
    gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
    v2printk("Singlestep stopped at IP: %lx\n",
           instruction_pointer(&kgdbts_regs));

    if (sstep_thread_id != cont_thread_id) {
        /*
         * Ensure we stopped in the same thread id as before, else the
         * debugger should continue until the original thread that was
         * single stepped is scheduled again, emulating gdb's behavior.
         */
        v2printk("ThrID does not match: %lx\n", cont_thread_id);
        if (arch_needs_sstep_emulation) {
            if (matched_id &&
                instruction_pointer(&kgdbts_regs) != addr)
                goto continue_test;
            matched_id++;
            ts.idx -= 2;
            sstep_state = 0;
            return 0;
        }
        cont_instead_of_sstep = 1;
        ts.idx -= 4;
        return 0;
    }
continue_test:
    matched_id = 0;
    if (instruction_pointer(&kgdbts_regs) == addr) {
        eprintk("kgdbts: SingleStep failed at %lx\n",
               instruction_pointer(&kgdbts_regs));
        return 1;
    }

    return 0;
}

static void write_regs(char *arg)
{
    memset(scratch_buf, 0, sizeof(scratch_buf));
    scratch_buf[0] = 'G';
    pt_regs_to_gdb_regs(kgdbts_gdb_regs, &kgdbts_regs);
    kgdb_mem2hex((char *)kgdbts_gdb_regs, &scratch_buf[1], NUMREGBYTES);
    fill_get_buf(scratch_buf);
}

static void skip_back_repeat_test(char *arg)
{
    int go_back = simple_strtol(arg, NULL, 10);

    repeat_test--;
    if (repeat_test <= 0)
        ts.idx++;
    else
        ts.idx -= go_back;
    fill_get_buf(ts.tst[ts.idx].get);
}

static int got_break(char *put_str, char *arg)
{
    test_complete = 1;
    if (!strncmp(put_str+1, arg, 2)) {
        if (!strncmp(arg, "T0", 2))
            test_complete = 2;
        return 0;
    }
    return 1;
}

static void get_cont_catch(char *arg)
{
    /* Always send detach because the test is completed at this point */
    fill_get_buf("D");
}

static int put_cont_catch(char *put_str, char *arg)
{
    /* This is at the end of the test and we catch any and all input */
    v2printk("kgdbts: cleanup task: %lx\n", sstep_thread_id);
    ts.idx--;
    return 0;
}

static int emul_reset(char *put_str, char *arg)
{
    if (strncmp(put_str, "$OK", 3))
        return 1;
    if (restart_from_top_after_write) {
        restart_from_top_after_write = 0;
        ts.idx = -1;
    }
    return 0;
}

static void emul_sstep_get(char *arg)
{
    if (!arch_needs_sstep_emulation) {
        if (cont_instead_of_sstep) {
            cont_instead_of_sstep = 0;
            fill_get_buf("c");
        } else {
            fill_get_buf(arg);
        }
        return;
    }
    switch (sstep_state) {
    case 0:
        v2printk("Emulate single step\n");
        /* Start by looking at the current PC */
        fill_get_buf("g");
        break;
    case 1:
        /* set breakpoint */
        break_helper("Z0", NULL, sstep_addr);
        break;
    case 2:
        /* Continue */
        fill_get_buf("c");
        break;
    case 3:
        /* Clear breakpoint */
        break_helper("z0", NULL, sstep_addr);
        break;
    default:
        eprintk("kgdbts: ERROR failed sstep get emulation\n");
    }
    sstep_state++;
}

static int emul_sstep_put(char *put_str, char *arg)
{
    if (!arch_needs_sstep_emulation) {
        char *ptr = &put_str[11];
        if (put_str[1] != 'T' || put_str[2] != '0')
            return 1;
        kgdb_hex2long(&ptr, &sstep_thread_id);
        return 0;
    }
    switch (sstep_state) {
    case 1:
        /* validate the "g" packet to get the IP */
        kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
             NUMREGBYTES);
        gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
        v2printk("Stopped at IP: %lx\n",
             instruction_pointer(&kgdbts_regs));
        /* Want to stop at IP + break instruction size by default */
        sstep_addr = cont_addr + BREAK_INSTR_SIZE;
        break;
    case 2:
        if (strncmp(put_str, "$OK", 3)) {
            eprintk("kgdbts: failed sstep break set\n");
            return 1;
        }
        break;
    case 3:
        if (strncmp(put_str, "$T0", 3)) {
            eprintk("kgdbts: failed continue sstep\n");
            return 1;
        } else {
            char *ptr = &put_str[11];
            kgdb_hex2long(&ptr, &sstep_thread_id);
        }
        break;
    case 4:
        if (strncmp(put_str, "$OK", 3)) {
            eprintk("kgdbts: failed sstep break unset\n");
            return 1;
        }
        /* Single step is complete so continue on! */
        sstep_state = 0;
        return 0;
    default:
        eprintk("kgdbts: ERROR failed sstep put emulation\n");
    }

    /* Continue on the same test line until emulation is complete */
    ts.idx--;
    return 0;
}

static int final_ack_set(char *put_str, char *arg)
{
    if (strncmp(put_str+1, arg, 2))
        return 1;
    final_ack = 1;
    return 0;
}
/*
 * Test to plant a breakpoint and detach, which should clear out the
 * breakpoint and restore the original instruction.
 */
static struct test_struct plant_and_detach_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
    { "D", "OK" }, /* Detach */
    { "", "" },
};

/*
 * Simple test to write in a software breakpoint, check for the
 * correct stop location and detach.
 */
static struct test_struct sw_breakpoint_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
    { "c", "T0*", }, /* Continue */
    { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs },
    { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
    { "D", "OK" }, /* Detach */
    { "D", "OK", NULL,  got_break }, /* On success we made it here */
    { "", "" },
};

/*
 * Test a known bad memory read location to test the fault handler and
 * read bytes 1-8 at the bad address
 */
static struct test_struct bad_read_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "m0,1", "E*" }, /* read 1 byte at address 1 */
    { "m0,2", "E*" }, /* read 1 byte at address 2 */
    { "m0,3", "E*" }, /* read 1 byte at address 3 */
    { "m0,4", "E*" }, /* read 1 byte at address 4 */
    { "m0,5", "E*" }, /* read 1 byte at address 5 */
    { "m0,6", "E*" }, /* read 1 byte at address 6 */
    { "m0,7", "E*" }, /* read 1 byte at address 7 */
    { "m0,8", "E*" }, /* read 1 byte at address 8 */
    { "D", "OK" }, /* Detach which removes all breakpoints and continues */
    { "", "" },
};

/*
 * Test for hitting a breakpoint, remove it, single step, plant it
 * again and detach.
 */
static struct test_struct singlestep_break_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
    { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
    { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */
    { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs }, /* Write registers */
    { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
    { "g", "kgdbts_break_test", NULL, check_single_step },
    { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */
    { "c", "T0*", }, /* Continue */
    { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs }, /* Write registers */
    { "D", "OK" }, /* Remove all breakpoints and continues */
    { "", "" },
};

/*
 * Test for hitting a breakpoint at do_fork for what ever the number
 * of iterations required by the variable repeat_test.
 */
static struct test_struct do_fork_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "do_fork", "OK", sw_break, }, /* set sw breakpoint */
    { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
    { "do_fork", "OK", sw_rem_break }, /*remove breakpoint */
    { "g", "do_fork", NULL, check_and_rewind_pc }, /* check location */
    { "write", "OK", write_regs, emul_reset }, /* Write registers */
    { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
    { "g", "do_fork", NULL, check_single_step },
    { "do_fork", "OK", sw_break, }, /* set sw breakpoint */
    { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
    { "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
    { "", "", get_cont_catch, put_cont_catch },
};

/* Test for hitting a breakpoint at sys_open for what ever the number
 * of iterations required by the variable repeat_test.
 */
static struct test_struct sys_open_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "sys_open", "OK", sw_break, }, /* set sw breakpoint */
    { "c", "T0*", NULL, get_thread_id_continue }, /* Continue */
    { "sys_open", "OK", sw_rem_break }, /*remove breakpoint */
    { "g", "sys_open", NULL, check_and_rewind_pc }, /* check location */
    { "write", "OK", write_regs, emul_reset }, /* Write registers */
    { "s", "T0*", emul_sstep_get, emul_sstep_put }, /* Single step */
    { "g", "sys_open", NULL, check_single_step },
    { "sys_open", "OK", sw_break, }, /* set sw breakpoint */
    { "7", "T0*", skip_back_repeat_test }, /* Loop based on repeat_test */
    { "D", "OK", NULL, final_ack_set }, /* detach and unregister I/O */
    { "", "", get_cont_catch, put_cont_catch },
};

/*
 * Test for hitting a simple hw breakpoint
 */
static struct test_struct hw_breakpoint_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "kgdbts_break_test", "OK", hw_break, }, /* set hw breakpoint */
    { "c", "T0*", }, /* Continue */
    { "g", "kgdbts_break_test", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs },
    { "kgdbts_break_test", "OK", hw_rem_break }, /*remove breakpoint */
    { "D", "OK" }, /* Detach */
    { "D", "OK", NULL,  got_break }, /* On success we made it here */
    { "", "" },
};

/*
 * Test for hitting a hw write breakpoint
 */
static struct test_struct hw_write_break_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "hw_break_val", "OK", hw_write_break, }, /* set hw breakpoint */
    { "c", "T0*", NULL, got_break }, /* Continue */
    { "g", "silent", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs },
    { "hw_break_val", "OK", hw_rem_write_break }, /*remove breakpoint */
    { "D", "OK" }, /* Detach */
    { "D", "OK", NULL,  got_break }, /* On success we made it here */
    { "", "" },
};

/*
 * Test for hitting a hw access breakpoint
 */
static struct test_struct hw_access_break_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "hw_break_val", "OK", hw_access_break, }, /* set hw breakpoint */
    { "c", "T0*", NULL, got_break }, /* Continue */
    { "g", "silent", NULL, check_and_rewind_pc },
    { "write", "OK", write_regs },
    { "hw_break_val", "OK", hw_rem_access_break }, /*remove breakpoint */
    { "D", "OK" }, /* Detach */
    { "D", "OK", NULL,  got_break }, /* On success we made it here */
    { "", "" },
};

/*
 * Test for hitting a hw access breakpoint
 */
static struct test_struct nmi_sleep_test[] = {
    { "?", "S0*" }, /* Clear break points */
    { "c", "T0*", NULL, got_break }, /* Continue */
    { "D", "OK" }, /* Detach */
    { "D", "OK", NULL,  got_break }, /* On success we made it here */
    { "", "" },
};

static void fill_get_buf(char *buf)
{
    unsigned char checksum = 0;
    int count = 0;
    char ch;

    strcpy(get_buf, "$");
    strcat(get_buf, buf);
    while ((ch = buf[count])) {
        checksum += ch;
        count++;
    }
    strcat(get_buf, "#");
    get_buf[count + 2] = hex_asc_hi(checksum);
    get_buf[count + 3] = hex_asc_lo(checksum);
    get_buf[count + 4] = '\0';
    v2printk("get%i: %s\n", ts.idx, get_buf);
}

static int validate_simple_test(char *put_str)
{
    char *chk_str;

    if (ts.tst[ts.idx].put_handler)
        return ts.tst[ts.idx].put_handler(put_str,
            ts.tst[ts.idx].put);

    chk_str = ts.tst[ts.idx].put;
    if (*put_str == '$')
        put_str++;

    while (*chk_str != '\0' && *put_str != '\0') {
        /* If someone does a * to match the rest of the string, allow
         * it, or stop if the received string is complete.
         */
        if (*put_str == '#' || *chk_str == '*')
            return 0;
        if (*put_str != *chk_str)
            return 1;

        chk_str++;
        put_str++;
    }
    if (*chk_str == '\0' && (*put_str == '\0' || *put_str == '#'))
        return 0;

    return 1;
}

static int run_simple_test(int is_get_char, int chr)
{
    int ret = 0;
    if (is_get_char) {
        /* Send an ACK on the get if a prior put completed and set the
         * send ack variable
         */
        if (send_ack) {
            send_ack = 0;
            return '+';
        }
        /* On the first get char, fill the transmit buffer and then
         * take from the get_string.
         */
        if (get_buf_cnt == 0) {
            if (ts.tst[ts.idx].get_handler)
                ts.tst[ts.idx].get_handler(ts.tst[ts.idx].get);
            else
                fill_get_buf(ts.tst[ts.idx].get);
        }

        if (get_buf[get_buf_cnt] == '\0') {
            eprintk("kgdbts: ERROR GET: EOB on '%s' at %i\n",
               ts.name, ts.idx);
            get_buf_cnt = 0;
            fill_get_buf("D");
        }
        ret = get_buf[get_buf_cnt];
        get_buf_cnt++;
        return ret;
    }

    /* This callback is a put char which is when kgdb sends data to
     * this I/O module.
     */
    if (ts.tst[ts.idx].get[0] == '\0' && ts.tst[ts.idx].put[0] == '\0' &&
        !ts.tst[ts.idx].get_handler) {
        eprintk("kgdbts: ERROR: beyond end of test on"
               " '%s' line %i\n", ts.name, ts.idx);
        return 0;
    }

    if (put_buf_cnt >= BUFMAX) {
        eprintk("kgdbts: ERROR: put buffer overflow on"
               " '%s' line %i\n", ts.name, ts.idx);
        put_buf_cnt = 0;
        return 0;
    }
    /* Ignore everything until the first valid packet start '$' */
    if (put_buf_cnt == 0 && chr != '$')
        return 0;

    put_buf[put_buf_cnt] = chr;
    put_buf_cnt++;

    /* End of packet == #XX so look for the '#' */
    if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') {
        if (put_buf_cnt >= BUFMAX) {
            eprintk("kgdbts: ERROR: put buffer overflow on"
                " '%s' line %i\n", ts.name, ts.idx);
            put_buf_cnt = 0;
            return 0;
        }
        put_buf[put_buf_cnt] = '\0';
        v2printk("put%i: %s\n", ts.idx, put_buf);
        /* Trigger check here */
        if (ts.validate_put && ts.validate_put(put_buf)) {
            eprintk("kgdbts: ERROR PUT: end of test "
               "buffer on '%s' line %i expected %s got %s\n",
               ts.name, ts.idx, ts.tst[ts.idx].put, put_buf);
        }
        ts.idx++;
        put_buf_cnt = 0;
        get_buf_cnt = 0;
        send_ack = 1;
    }
    return 0;
}

static void init_simple_test(void)
{
    memset(&ts, 0, sizeof(ts));
    ts.run_test = run_simple_test;
    ts.validate_put = validate_simple_test;
}

static void run_plant_and_detach_test(int is_early)
{
    char before[BREAK_INSTR_SIZE];
    char after[BREAK_INSTR_SIZE];

    probe_kernel_read(before, (char *)kgdbts_break_test,
      BREAK_INSTR_SIZE);
    init_simple_test();
    ts.tst = plant_and_detach_test;
    ts.name = "plant_and_detach_test";
    /* Activate test with initial breakpoint */
    if (!is_early)
        kgdb_breakpoint();
    probe_kernel_read(after, (char *)kgdbts_break_test,
      BREAK_INSTR_SIZE);
    if (memcmp(before, after, BREAK_INSTR_SIZE)) {
        printk(KERN_CRIT "kgdbts: ERROR kgdb corrupted memory\n");
        panic("kgdb memory corruption");
    }

    /* complete the detach test */
    if (!is_early)
        kgdbts_break_test();
}

static void run_breakpoint_test(int is_hw_breakpoint)
{
    test_complete = 0;
    init_simple_test();
    if (is_hw_breakpoint) {
        ts.tst = hw_breakpoint_test;
        ts.name = "hw_breakpoint_test";
    } else {
        ts.tst = sw_breakpoint_test;
        ts.name = "sw_breakpoint_test";
    }
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
    /* run code with the break point in it */
    kgdbts_break_test();
    kgdb_breakpoint();

    if (test_complete)
        return;

    eprintk("kgdbts: ERROR %s test failed\n", ts.name);
    if (is_hw_breakpoint)
        hwbreaks_ok = 0;
}

static void run_hw_break_test(int is_write_test)
{
    test_complete = 0;
    init_simple_test();
    if (is_write_test) {
        ts.tst = hw_write_break_test;
        ts.name = "hw_write_break_test";
    } else {
        ts.tst = hw_access_break_test;
        ts.name = "hw_access_break_test";
    }
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
    hw_break_val_access();
    if (is_write_test) {
        if (test_complete == 2) {
            eprintk("kgdbts: ERROR %s broke on access\n",
                ts.name);
            hwbreaks_ok = 0;
        }
        hw_break_val_write();
    }
    kgdb_breakpoint();

    if (test_complete == 1)
        return;

    eprintk("kgdbts: ERROR %s test failed\n", ts.name);
    hwbreaks_ok = 0;
}

static void run_nmi_sleep_test(int nmi_sleep)
{
    unsigned long flags;

    init_simple_test();
    ts.tst = nmi_sleep_test;
    ts.name = "nmi_sleep_test";
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
    local_irq_save(flags);
    mdelay(nmi_sleep*1000);
    touch_nmi_watchdog();
    local_irq_restore(flags);
    if (test_complete != 2)
        eprintk("kgdbts: ERROR nmi_test did not hit nmi\n");
    kgdb_breakpoint();
    if (test_complete == 1)
        return;

    eprintk("kgdbts: ERROR %s test failed\n", ts.name);
}

static void run_bad_read_test(void)
{
    init_simple_test();
    ts.tst = bad_read_test;
    ts.name = "bad_read_test";
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
}

static void run_do_fork_test(void)
{
    init_simple_test();
    ts.tst = do_fork_test;
    ts.name = "do_fork_test";
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
}

static void run_sys_open_test(void)
{
    init_simple_test();
    ts.tst = sys_open_test;
    ts.name = "sys_open_test";
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
}

static void run_singlestep_break_test(void)
{
    init_simple_test();
    ts.tst = singlestep_break_test;
    ts.name = "singlestep_breakpoint_test";
    /* Activate test with initial breakpoint */
    kgdb_breakpoint();
    kgdbts_break_test();
    kgdbts_break_test();
}

static void kgdbts_run_tests(void)
{
    char *ptr;
    int fork_test = 0;
    int do_sys_open_test = 0;
    int sstep_test = 1000;
    int nmi_sleep = 0;
    int i;

    ptr = strchr(config, 'F');
    if (ptr)
        fork_test = simple_strtol(ptr + 1, NULL, 10);
    ptr = strchr(config, 'S');
    if (ptr)
        do_sys_open_test = simple_strtol(ptr + 1, NULL, 10);
    ptr = strchr(config, 'N');
    if (ptr)
        nmi_sleep = simple_strtol(ptr+1, NULL, 10);
    ptr = strchr(config, 'I');
    if (ptr)
        sstep_test = simple_strtol(ptr+1, NULL, 10);

    /* All HW break point tests */
    if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT) {
        hwbreaks_ok = 1;
        v1printk("kgdbts:RUN hw breakpoint test\n");
        run_breakpoint_test(1);
        v1printk("kgdbts:RUN hw write breakpoint test\n");
        run_hw_break_test(1);
        v1printk("kgdbts:RUN access write breakpoint test\n");
        run_hw_break_test(0);
    }

    /* required internal KGDB tests */
    v1printk("kgdbts:RUN plant and detach test\n");
    run_plant_and_detach_test(0);
    v1printk("kgdbts:RUN sw breakpoint test\n");
    run_breakpoint_test(0);
    v1printk("kgdbts:RUN bad memory access test\n");
    run_bad_read_test();
    v1printk("kgdbts:RUN singlestep test %i iterations\n", sstep_test);
    for (i = 0; i < sstep_test; i++) {
        run_singlestep_break_test();
        if (i % 100 == 0)
            v1printk("kgdbts:RUN singlestep [%i/%i]\n",
                 i, sstep_test);
    }

    /* ===Optional tests=== */

    if (nmi_sleep) {
        v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep);
        run_nmi_sleep_test(nmi_sleep);
    }

    /* If the do_fork test is run it will be the last test that is
     * executed because a kernel thread will be spawned at the very
     * end to unregister the debug hooks.
     */
    if (fork_test) {
        repeat_test = fork_test;
        printk(KERN_INFO "kgdbts:RUN do_fork for %i breakpoints\n",
            repeat_test);
        kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
        run_do_fork_test();
        return;
    }

    /* If the sys_open test is run it will be the last test that is
     * executed because a kernel thread will be spawned at the very
     * end to unregister the debug hooks.
     */
    if (do_sys_open_test) {
        repeat_test = do_sys_open_test;
        printk(KERN_INFO "kgdbts:RUN sys_open for %i breakpoints\n",
            repeat_test);
        kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg");
        run_sys_open_test();
        return;
    }
    /* Shutdown and unregister */
    kgdb_unregister_io_module(&kgdbts_io_ops);
    configured = 0;
}

static int kgdbts_option_setup(char *opt)
{
    if (strlen(opt) >= MAX_CONFIG_LEN) {
        printk(KERN_ERR "kgdbts: config string too long\n");
        return -ENOSPC;
    }
    strcpy(config, opt);

    verbose = 0;
    if (strstr(config, "V1"))
        verbose = 1;
    if (strstr(config, "V2"))
        verbose = 2;

    return 0;
}

__setup("kgdbts=", kgdbts_option_setup);

static int configure_kgdbts(void)
{
    int err = 0;

    if (!strlen(config) || isspace(config[0]))
        goto noconfig;
    err = kgdbts_option_setup(config);
    if (err)
        goto noconfig;

    final_ack = 0;
    run_plant_and_detach_test(1);

    err = kgdb_register_io_module(&kgdbts_io_ops);
    if (err) {
        configured = 0;
        return err;
    }
    configured = 1;
    kgdbts_run_tests();

    return err;

noconfig:
    config[0] = 0;
    configured = 0;

    return err;
}

static int __init init_kgdbts(void)
{
    /* Already configured? */
    if (configured == 1)
        return 0;

    return configure_kgdbts();
}

static int kgdbts_get_char(void)
{
    int val = 0;

    if (ts.run_test)
        val = ts.run_test(1, 0);

    return val;
}

static void kgdbts_put_char(u8 chr)
{
    if (ts.run_test)
        ts.run_test(0, chr);
}

static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp)
{
    int len = strlen(kmessage);

    if (len >= MAX_CONFIG_LEN) {
        printk(KERN_ERR "kgdbts: config string too long\n");
        return -ENOSPC;
    }

    /* Only copy in the string if the init function has not run yet */
    if (configured < 0) {
        strcpy(config, kmessage);
        return 0;
    }

    if (configured == 1) {
        printk(KERN_ERR "kgdbts: ERROR: Already configured and running.\n");
        return -EBUSY;
    }

    strcpy(config, kmessage);
    /* Chop out \n char as a result of echo */
    if (config[len - 1] == '\n')
        config[len - 1] = '\0';

    /* Go and configure with the new params. */
    return configure_kgdbts();
}

static void kgdbts_pre_exp_handler(void)
{
    /* Increment the module count when the debugger is active */
    if (!kgdb_connected)
        try_module_get(THIS_MODULE);
}

static void kgdbts_post_exp_handler(void)
{
    /* decrement the module count when the debugger detaches */
    if (!kgdb_connected)
        module_put(THIS_MODULE);
}

static struct kgdb_io kgdbts_io_ops = {
    .name           = "kgdbts",
    .read_char      = kgdbts_get_char,
    .write_char     = kgdbts_put_char,
    .pre_exception      = kgdbts_pre_exp_handler,
    .post_exception     = kgdbts_post_exp_handler,
};

module_init(init_kgdbts);
module_param_call(kgdbts, param_set_kgdbts_var, param_get_string, &kps, 0644);
MODULE_PARM_DESC(kgdbts, "<A|V1|V2>[F#|S#][N#]");
MODULE_DESCRIPTION("KGDB Test Suite");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Wind River Systems, Inc.");