diff options
| -rw-r--r-- | arch/x86/kernel/kgdb.c | 60 | ||||
| -rw-r--r-- | drivers/misc/kgdbts.c | 160 | ||||
| -rw-r--r-- | include/linux/kgdb.h | 7 | ||||
| -rw-r--r-- | kernel/debug/debug_core.c | 53 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_io.c | 2 |
5 files changed, 204 insertions, 78 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index db6720edfdd04f..8bfb6146f75306 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -43,6 +43,8 @@ #include <linux/smp.h> #include <linux/nmi.h> #include <linux/hw_breakpoint.h> +#include <linux/uaccess.h> +#include <linux/memory.h> #include <asm/debugreg.h> #include <asm/apicdef.h> @@ -741,6 +743,64 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) regs->ip = ip; } +int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) +{ + int err; + char opc[BREAK_INSTR_SIZE]; + + bpt->type = BP_BREAKPOINT; + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + BREAK_INSTR_SIZE); + if (err) + return err; + err = probe_kernel_write((char *)bpt->bpt_addr, + arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); +#ifdef CONFIG_DEBUG_RODATA + if (!err) + return err; + /* + * It is safe to call text_poke() because normal kernel execution + * is stopped on all cores, so long as the text_mutex is not locked. + */ + if (mutex_is_locked(&text_mutex)) + return -EBUSY; + text_poke((void *)bpt->bpt_addr, arch_kgdb_ops.gdb_bpt_instr, + BREAK_INSTR_SIZE); + err = probe_kernel_read(opc, (char *)bpt->bpt_addr, BREAK_INSTR_SIZE); + if (err) + return err; + if (memcmp(opc, arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE)) + return -EINVAL; + bpt->type = BP_POKE_BREAKPOINT; +#endif /* CONFIG_DEBUG_RODATA */ + return err; +} + +int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) +{ +#ifdef CONFIG_DEBUG_RODATA + int err; + char opc[BREAK_INSTR_SIZE]; + + if (bpt->type != BP_POKE_BREAKPOINT) + goto knl_write; + /* + * It is safe to call text_poke() because normal kernel execution + * is stopped on all cores, so long as the text_mutex is not locked. + */ + if (mutex_is_locked(&text_mutex)) + goto knl_write; + text_poke((void *)bpt->bpt_addr, bpt->saved_instr, BREAK_INSTR_SIZE); + err = probe_kernel_read(opc, (char *)bpt->bpt_addr, BREAK_INSTR_SIZE); + if (err || memcmp(opc, bpt->saved_instr, BREAK_INSTR_SIZE)) + goto knl_write; + return err; +knl_write: +#endif /* CONFIG_DEBUG_RODATA */ + return probe_kernel_write((char *)bpt->bpt_addr, + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); +} + struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: */ .gdb_bpt_instr = { 0xcc }, diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index 3f7ad83ed740bc..3aa9a969b373a4 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -134,12 +134,17 @@ 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. */ @@ -187,7 +192,8 @@ static int kgdbts_unreg_thread(void *ptr) */ 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; @@ -211,7 +217,7 @@ static unsigned long lookup_addr(char *arg) if (!strcmp(arg, "kgdbts_break_test")) addr = (unsigned long)kgdbts_break_test; else if (!strcmp(arg, "sys_open")) - addr = (unsigned long)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")) @@ -283,6 +289,16 @@ 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); @@ -299,13 +315,21 @@ static int check_and_rewind_pc(char *put_str, char *arg) if (addr + BREAK_INSTR_SIZE == ip) offset = -BREAK_INSTR_SIZE; #endif - if (strcmp(arg, "silent") && ip + offset != addr) { + + 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 @@ -315,6 +339,8 @@ static int check_and_rewind_pc(char *put_str, char *arg) 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 @@ -324,6 +350,29 @@ static int check_single_step(char *put_str, char *arg) 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)); @@ -365,10 +414,40 @@ static int got_break(char *put_str, char *arg) 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, "$OK", 3)) + return 1; + if (restart_from_top_after_write) { + restart_from_top_after_write = 0; + ts.idx = -1; + } + return 0; +} + static void emul_sstep_get(char *arg) { if (!arch_needs_sstep_emulation) { - fill_get_buf(arg); + if (cont_instead_of_sstep) { + cont_instead_of_sstep = 0; + fill_get_buf("c"); + } else { + fill_get_buf(arg); + } return; } switch (sstep_state) { @@ -398,9 +477,11 @@ static void emul_sstep_get(char *arg) static int emul_sstep_put(char *put_str, char *arg) { if (!arch_needs_sstep_emulation) { - if (!strncmp(put_str+1, arg, 2)) - return 0; - return 1; + char *ptr = &put_str[11]; + if (put_str[1] != 'T' || put_str[2] != '0') + return 1; + kgdb_hex2long(&ptr, &sstep_thread_id); + return 0; } switch (sstep_state) { case 1: @@ -411,8 +492,7 @@ static int emul_sstep_put(char *put_str, char *arg) v2printk("Stopped at IP: %lx\n", instruction_pointer(&kgdbts_regs)); /* Want to stop at IP + break instruction size by default */ - sstep_addr = instruction_pointer(&kgdbts_regs) + - BREAK_INSTR_SIZE; + sstep_addr = cont_addr + BREAK_INSTR_SIZE; break; case 2: if (strncmp(put_str, "$OK", 3)) { @@ -424,6 +504,9 @@ static int emul_sstep_put(char *put_str, char *arg) 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: @@ -502,10 +585,10 @@ static struct test_struct bad_read_test[] = { static struct test_struct singlestep_break_test[] = { { "?", "S0*" }, /* Clear break points */ { "kgdbts_break_test", "OK", sw_break, }, /* set sw breakpoint */ - { "c", "T0*", }, /* Continue */ + { "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 */ - { "kgdbts_break_test", "OK", sw_rem_break }, /*remove breakpoint */ { "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 */ @@ -523,16 +606,16 @@ static struct test_struct singlestep_break_test[] = { static struct test_struct do_fork_test[] = { { "?", "S0*" }, /* Clear break points */ { "do_fork", "OK", sw_break, }, /* set sw breakpoint */ - { "c", "T0*", }, /* Continue */ - { "g", "do_fork", NULL, check_and_rewind_pc }, /* check location */ - { "write", "OK", write_regs }, /* Write registers */ + { "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 @@ -541,16 +624,16 @@ 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 */ - { "c", "T0*", }, /* Continue */ - { "g", "sys_open", NULL, check_and_rewind_pc }, /* check location */ - { "write", "OK", write_regs }, /* Write registers */ + { "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 }, }; /* @@ -693,8 +776,8 @@ static int run_simple_test(int is_get_char, int chr) /* 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') { + 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; @@ -907,6 +990,17 @@ static void kgdbts_run_tests(void) 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); @@ -924,35 +1018,11 @@ static void kgdbts_run_tests(void) /* ===Optional tests=== */ - /* 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); - } - if (nmi_sleep) { v1printk("kgdbts:RUN NMI sleep %i seconds test\n", nmi_sleep); run_nmi_sleep_test(nmi_sleep); } -#ifdef CONFIG_DEBUG_RODATA - /* Until there is an api to write to read-only text segments, use - * HW breakpoints for the remainder of any tests, else print a - * failure message if hw breakpoints do not work. - */ - if (!(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT && hwbreaks_ok)) { - eprintk("kgdbts: HW breakpoints do not work," - "skipping remaining tests\n"); - return; - } - force_hwbrks = 1; -#endif /* CONFIG_DEBUG_RODATA */ - /* 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. diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index fa391835508d9a..c4d2fc194edec1 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -63,7 +63,8 @@ enum kgdb_bptype { BP_HARDWARE_BREAKPOINT, BP_WRITE_WATCHPOINT, BP_READ_WATCHPOINT, - BP_ACCESS_WATCHPOINT + BP_ACCESS_WATCHPOINT, + BP_POKE_BREAKPOINT, }; enum kgdb_bpstate { @@ -207,8 +208,8 @@ extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); /* Optional functions. */ extern int kgdb_validate_break_address(unsigned long addr); -extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); -extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle); +extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); +extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); /** * kgdb_arch_late - Perform any architecture specific initalization. diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1dc53bae56e1f6..0557f24c6bca0d 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -160,37 +160,39 @@ early_param("nokgdbroundup", opt_nokgdbroundup); * Weak aliases for breakpoint management, * can be overriden by architectures when needed: */ -int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) +int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) { int err; - err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + BREAK_INSTR_SIZE); if (err) return err; - - return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, - BREAK_INSTR_SIZE); + err = probe_kernel_write((char *)bpt->bpt_addr, + arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); + return err; } -int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) +int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) { - return probe_kernel_write((char *)addr, - (char *)bundle, BREAK_INSTR_SIZE); + return probe_kernel_write((char *)bpt->bpt_addr, + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); } int __weak kgdb_validate_break_address(unsigned long addr) { - char tmp_variable[BREAK_INSTR_SIZE]; + struct kgdb_bkpt tmp; int err; - /* Validate setting the breakpoint and then removing it. In the + /* Validate setting the breakpoint and then removing it. If the * remove fails, the kernel needs to emit a bad message because we * are deep trouble not being able to put things back the way we * found them. */ - err = kgdb_arch_set_breakpoint(addr, tmp_variable); + tmp.bpt_addr = addr; + err = kgdb_arch_set_breakpoint(&tmp); if (err) return err; - err = kgdb_arch_remove_breakpoint(addr, tmp_variable); + err = kgdb_arch_remove_breakpoint(&tmp); if (err) printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " "memory destroyed at: %lx", addr); @@ -234,7 +236,6 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) */ int dbg_activate_sw_breakpoints(void) { - unsigned long addr; int error; int ret = 0; int i; @@ -243,16 +244,15 @@ int dbg_activate_sw_breakpoints(void) if (kgdb_break[i].state != BP_SET) continue; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_set_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_set_breakpoint(&kgdb_break[i]); if (error) { ret = error; - printk(KERN_INFO "KGDB: BP install failed: %lx", addr); + printk(KERN_INFO "KGDB: BP install failed: %lx", + kgdb_break[i].bpt_addr); continue; } - kgdb_flush_swbreak_addr(addr); + kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr); kgdb_break[i].state = BP_ACTIVE; } return ret; @@ -301,7 +301,6 @@ int dbg_set_sw_break(unsigned long addr) int dbg_deactivate_sw_breakpoints(void) { - unsigned long addr; int error; int ret = 0; int i; @@ -309,15 +308,14 @@ int dbg_deactivate_sw_breakpoints(void) for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state != BP_ACTIVE) continue; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) { - printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr); + printk(KERN_INFO "KGDB: BP remove failed: %lx\n", + kgdb_break[i].bpt_addr); ret = error; } - kgdb_flush_swbreak_addr(addr); + kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr); kgdb_break[i].state = BP_SET; } return ret; @@ -351,7 +349,6 @@ int kgdb_isremovedbreak(unsigned long addr) int dbg_remove_all_break(void) { - unsigned long addr; int error; int i; @@ -359,12 +356,10 @@ int dbg_remove_all_break(void) for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state != BP_ACTIVE) goto setundefined; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", - addr); + kgdb_break[i].bpt_addr); setundefined: kgdb_break[i].state = BP_UNDEFINED; } diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 9b5f17da1c560e..bb9520f0f6ff8e 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -743,7 +743,7 @@ kdb_printit: kdb_input_flush(); c = console_drivers; - if (!dbg_io_ops->is_console) { + if (dbg_io_ops && !dbg_io_ops->is_console) { len = strlen(moreprompt); cp = moreprompt; while (len--) { |