diff options
Diffstat (limited to 'drivers/misc/kgdbts.c')
| -rw-r--r-- | drivers/misc/kgdbts.c | 190 |
1 files changed, 96 insertions, 94 deletions
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index 36f5d52775a9..0cf31164b470 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * 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 @@ -6,19 +7,6 @@ * Created by: Jason Wessel <jason.wessel@windriver.com> * * 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. * ------------------------------------- @@ -45,16 +33,16 @@ * 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 + * F## = Break at kernel_clone 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. + * NOTE: that the kernel_clone 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 + * Or if you wanted to perform the NMI test for 6 seconds and kernel_clone * test for 100 forks, you could use: * kgdbts=V1N6F100 kgdbwait * @@ -86,7 +74,7 @@ * 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 + * ## This tests break points on kernel_clone * while [ 1 ] ; do date > /dev/null ; done & * while [ 1 ] ; do date > /dev/null ; done & * echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts @@ -103,21 +91,26 @@ #include <linux/delay.h> #include <linux/kthread.h> #include <linux/module.h> -#include <asm/sections.h> +#include <linux/sched/task.h> +#include <linux/kallsyms.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) +#include <asm/sections.h> +#include <asm/rwonce.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; @@ -134,7 +127,6 @@ 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; @@ -210,21 +202,30 @@ static noinline void kgdbts_break_test(void) v2printk("kgdbts: breakpoint complete\n"); } -/* Lookup symbol info in the kernel */ +/* + * This is a cached wrapper for kallsyms_lookup_name(). + * + * The cache is a big win for several tests. For example it more the doubles + * the cycles per second during the sys_open test. This is not theoretic, + * the performance improvement shows up at human scale, especially when + * testing using emulators. + * + * Obviously neither re-entrant nor thread-safe but that is OK since it + * can only be called from the debug trap (and therefore all other CPUs + * are halted). + */ 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; - addr = (unsigned long) dereference_function_descriptor((void *)addr); - return addr; + static char cached_arg[KSYM_NAME_LEN]; + static unsigned long cached_addr; + + if (strcmp(arg, cached_arg)) { + strscpy(cached_arg, arg, KSYM_NAME_LEN); + cached_addr = kallsyms_lookup_name(arg); + } + + return (unsigned long)dereference_function_descriptor( + (void *)cached_addr); } static void break_helper(char *bp_type, char *arg, unsigned long vaddr) @@ -283,7 +284,7 @@ static void hw_rem_access_break(char *arg) static void hw_break_val_access(void) { - hw_break_val2 = hw_break_val; + READ_ONCE(hw_break_val); } static void hw_break_val_write(void) @@ -320,7 +321,7 @@ static int check_and_rewind_pc(char *put_str, char *arg) if (arch_needs_sstep_emulation && sstep_addr && ip + offset == sstep_addr && - ((!strcmp(arg, "sys_open") || !strcmp(arg, "do_fork")))) { + ((!strcmp(arg, "do_sys_openat2") || !strcmp(arg, "kernel_clone")))) { /* This is special case for emulated single step */ v2printk("Emul: rewind hit single step bp\n"); restart_from_top_after_write = 1; @@ -398,10 +399,14 @@ static void skip_back_repeat_test(char *arg) int go_back = simple_strtol(arg, NULL, 10); repeat_test--; - if (repeat_test <= 0) + if (repeat_test <= 0) { ts.idx++; - else + } else { + if (repeat_test % 100 == 0) + v1printk("kgdbts:RUN ... %d remaining\n", repeat_test); + ts.idx -= go_back; + } fill_get_buf(ts.tst[ts.idx].get); } @@ -602,19 +607,19 @@ static struct test_struct singlestep_break_test[] = { }; /* - * Test for hitting a breakpoint at do_fork for what ever the number + * Test for hitting a breakpoint at kernel_clone for what ever the number * of iterations required by the variable repeat_test. */ -static struct test_struct do_fork_test[] = { +static struct test_struct do_kernel_clone_test[] = { { "?", "S0*" }, /* Clear break points */ - { "do_fork", "OK", sw_break, }, /* set sw breakpoint */ + { "kernel_clone", "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 */ + { "kernel_clone", "OK", sw_rem_break }, /*remove breakpoint */ + { "g", "kernel_clone", 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 */ + { "g", "kernel_clone", NULL, check_single_step }, + { "kernel_clone", "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 }, @@ -625,14 +630,14 @@ static struct test_struct do_fork_test[] = { */ static struct test_struct sys_open_test[] = { { "?", "S0*" }, /* Clear break points */ - { "sys_open", "OK", sw_break, }, /* set sw breakpoint */ + { "do_sys_openat2", "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 */ + { "do_sys_openat2", "OK", sw_rem_break }, /*remove breakpoint */ + { "g", "do_sys_openat2", 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 */ + { "g", "do_sys_openat2", NULL, check_single_step }, + { "do_sys_openat2", "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 }, @@ -834,7 +839,7 @@ 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, + copy_from_kernel_nofault(before, (char *)kgdbts_break_test, BREAK_INSTR_SIZE); init_simple_test(); ts.tst = plant_and_detach_test; @@ -842,8 +847,8 @@ static void run_plant_and_detach_test(int is_early) /* Activate test with initial breakpoint */ if (!is_early) kgdb_breakpoint(); - probe_kernel_read(after, (char *)kgdbts_break_test, - BREAK_INSTR_SIZE); + copy_from_kernel_nofault(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"); @@ -941,11 +946,11 @@ static void run_bad_read_test(void) kgdb_breakpoint(); } -static void run_do_fork_test(void) +static void run_kernel_clone_test(void) { init_simple_test(); - ts.tst = do_fork_test; - ts.name = "do_fork_test"; + ts.tst = do_kernel_clone_test; + ts.name = "do_kernel_clone_test"; /* Activate test with initial breakpoint */ kgdb_breakpoint(); } @@ -973,15 +978,21 @@ static void run_singlestep_break_test(void) static void kgdbts_run_tests(void) { char *ptr; - int fork_test = 0; + int clone_test = 0; int do_sys_open_test = 0; int sstep_test = 1000; int nmi_sleep = 0; int i; + verbose = 0; + if (strstr(config, "V1")) + verbose = 1; + if (strstr(config, "V2")) + verbose = 2; + ptr = strchr(config, 'F'); if (ptr) - fork_test = simple_strtol(ptr + 1, NULL, 10); + clone_test = simple_strtol(ptr + 1, NULL, 10); ptr = strchr(config, 'S'); if (ptr) do_sys_open_test = simple_strtol(ptr + 1, NULL, 10); @@ -1025,16 +1036,16 @@ static void kgdbts_run_tests(void) run_nmi_sleep_test(nmi_sleep); } - /* If the do_fork test is run it will be the last test that is + /* If the kernel_clone 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", + if (clone_test) { + repeat_test = clone_test; + printk(KERN_INFO "kgdbts:RUN kernel_clone for %i breakpoints\n", repeat_test); kthread_run(kgdbts_unreg_thread, NULL, "kgdbts_unreg"); - run_do_fork_test(); + run_kernel_clone_test(); return; } @@ -1059,17 +1070,10 @@ static int kgdbts_option_setup(char *opt) { if (strlen(opt) >= MAX_CONFIG_LEN) { printk(KERN_ERR "kgdbts: config string too long\n"); - return -ENOSPC; + return 1; } strcpy(config, opt); - - verbose = 0; - if (strstr(config, "V1")) - verbose = 1; - if (strstr(config, "V2")) - verbose = 2; - - return 0; + return 1; } __setup("kgdbts=", kgdbts_option_setup); @@ -1080,9 +1084,6 @@ static int configure_kgdbts(void) 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); @@ -1112,6 +1113,7 @@ static int __init init_kgdbts(void) return configure_kgdbts(); } +device_initcall(init_kgdbts); static int kgdbts_get_char(void) { @@ -1129,9 +1131,10 @@ static void kgdbts_put_char(u8 chr) ts.run_test(0, chr); } -static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp) +static int param_set_kgdbts_var(const char *kmessage, + const struct kernel_param *kp) { - int len = strlen(kmessage); + size_t len = strlen(kmessage); if (len >= MAX_CONFIG_LEN) { printk(KERN_ERR "kgdbts: config string too long\n"); @@ -1151,7 +1154,7 @@ static int param_set_kgdbts_var(const char *kmessage, struct kernel_param *kp) strcpy(config, kmessage); /* Chop out \n char as a result of echo */ - if (config[len - 1] == '\n') + if (len && config[len - 1] == '\n') config[len - 1] = '\0'; /* Go and configure with the new params. */ @@ -1180,10 +1183,9 @@ static struct kgdb_io kgdbts_io_ops = { .post_exception = kgdbts_post_exp_handler, }; -module_init(init_kgdbts); +/* + * not really modular, but the easiest way to keep compat with existing + * bootargs behaviour is to continue using module_param here. + */ 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."); - |