diff options
Diffstat (limited to 'drivers/misc/kgdbts.c')
| -rw-r--r-- | drivers/misc/kgdbts.c | 74 |
1 files changed, 42 insertions, 32 deletions
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index 945701bce553..64d33e368509 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -92,22 +92,23 @@ #include <linux/kthread.h> #include <linux/module.h> #include <linux/sched/task.h> +#include <linux/kallsyms.h> #include <asm/sections.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 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; @@ -200,21 +201,30 @@ 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, "kernel_clone")) - addr = (unsigned long)kernel_clone; - 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) @@ -310,7 +320,7 @@ 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, "kernel_clone")))) { + ((!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; @@ -619,14 +629,14 @@ static struct test_struct do_kernel_clone_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 }, |