diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index bdce359820bb1683160931644836b25efe0b8af3..f5fce483930cf933d0eb7928f1a4fa6cfe8ff921 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -713,6 +713,12 @@ and is between 256 and 4096 characters. It is defined in the file The VGA output is eventually overwritten by the real console. + ekgdboc= [X86,KGDB] Allow early kernel console debugging + ekgdboc=kbd + + This is desgined to be used in conjunction with + the boot argument: earlyprintk=vga + eata= [HW,SCSI] edd= [EDD] @@ -1121,6 +1127,17 @@ and is between 256 and 4096 characters. It is defined in the file use the HighMem zone if it exists, and the Normal zone if it does not. + kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. + Format: [,poll interval] + The controller # is the number of the ehci usb debug + port as it is probed via PCI. The poll interval is + optional and is the number seconds in between + each poll cycle to the debug port in case you need + the functionality for interrupting the kernel with + gdb or control-c on the dbgp connection. When + not using this parameter you use sysrq-g to break into + the kernel debugger. + kgdboc= [KGDB,HW] kgdb over consoles. Requires a tty driver that supports console polling, or a supported polling keyboard driver (non-usb). diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 5a51379dcbe4a7c3dab91a157f752d4c58889117..7e5c6a60b8ee190ab85b8ed88503ec2436197ea9 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -789,6 +789,8 @@ static inline void wbinvd_halt(void) extern void enable_sep_cpu(void); extern int sysenter_setup(void); +extern void early_trap_init(void); + /* Defined in head.S */ extern struct desc_ptr early_gdt_descr; diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c1c00d0b1692d47bf45981439122b962a9b1dac0..cc83a002786e0bb16163afd17ffba909f88abe14 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1084,6 +1084,20 @@ static void clear_all_debug_regs(void) } } +#ifdef CONFIG_KGDB +/* + * Restore debug regs if using kgdbwait and you have a kernel debugger + * connection established. + */ +static void dbg_restore_debug_regs(void) +{ + if (unlikely(kgdb_connected && arch_kgdb_ops.correct_hw_break)) + arch_kgdb_ops.correct_hw_break(); +} +#else /* ! CONFIG_KGDB */ +#define dbg_restore_debug_regs() +#endif /* ! CONFIG_KGDB */ + /* * cpu_init() initializes state that is per-CPU. Some data is already * initialized (naturally) in the bootstrap process, such as the GDT @@ -1174,18 +1188,8 @@ void __cpuinit cpu_init(void) load_TR_desc(); load_LDT(&init_mm.context); -#ifdef CONFIG_KGDB - /* - * If the kgdb is connected no debug regs should be altered. This - * is only applicable when KGDB and a KGDB I/O module are built - * into the kernel and you are using early debugging with - * kgdbwait. KGDB will control the kernel HW breakpoint registers. - */ - if (kgdb_connected && arch_kgdb_ops.correct_hw_break) - arch_kgdb_ops.correct_hw_break(); - else -#endif - clear_all_debug_regs(); + clear_all_debug_regs(); + dbg_restore_debug_regs(); fpu_init(); @@ -1239,6 +1243,7 @@ void __cpuinit cpu_init(void) #endif clear_all_debug_regs(); + dbg_restore_debug_regs(); /* * Force FPU initialization: diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index b9c830c12b4ac1de45d137a736be6de7fbd19fb4..fa99bae75acee4d1efb12b141a24d97019e03b5f 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -41,6 +41,14 @@ static void early_vga_write(struct console *con, const char *str, unsigned n) writew(0x720, VGABASE + 2*(max_xpos*j + i)); current_ypos = max_ypos-1; } +#ifdef CONFIG_KGDB_KDB + if (c == '\b') { + if (current_xpos > 0) + current_xpos--; + } else if (c == '\r') { + current_xpos = 0; + } else +#endif if (c == '\n') { current_xpos = 0; current_ypos++; diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 95b89d4cb8f18f1595a430e0e6eaf8ac5f513487..4f4af75b94828af47b811b6b5c6a45e7c4ae650e 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -199,6 +199,8 @@ static struct hw_breakpoint { struct perf_event **pev; } breakinfo[4]; +static unsigned long early_dr7; + static void kgdb_correct_hw_break(void) { int breakno; @@ -210,6 +212,14 @@ static void kgdb_correct_hw_break(void) int cpu = raw_smp_processor_id(); if (!breakinfo[breakno].enabled) continue; + if (dbg_is_early) { + set_debugreg(breakinfo[breakno].addr, breakno); + early_dr7 |= encode_dr7(breakno, + breakinfo[breakno].len, + breakinfo[breakno].type); + set_debugreg(early_dr7, 7); + continue; + } bp = *per_cpu_ptr(breakinfo[breakno].pev, cpu); info = counter_arch_bp(bp); if (bp->attr.disabled != 1) @@ -224,7 +234,8 @@ static void kgdb_correct_hw_break(void) if (!val) bp->attr.disabled = 0; } - hw_breakpoint_restore(); + if (!dbg_is_early) + hw_breakpoint_restore(); } static int hw_break_reserve_slot(int breakno) @@ -233,6 +244,9 @@ static int hw_break_reserve_slot(int breakno) int cnt = 0; struct perf_event **pevent; + if (dbg_is_early) + return 0; + for_each_online_cpu(cpu) { cnt++; pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu); @@ -258,6 +272,9 @@ static int hw_break_release_slot(int breakno) struct perf_event **pevent; int cpu; + if (dbg_is_early) + return 0; + for_each_online_cpu(cpu) { pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu); if (dbg_release_bp_slot(*pevent)) @@ -302,7 +319,11 @@ static void kgdb_remove_all_hw_break(void) bp = *per_cpu_ptr(breakinfo[i].pev, cpu); if (bp->attr.disabled == 1) continue; - arch_uninstall_hw_breakpoint(bp); + if (dbg_is_early) + early_dr7 &= ~encode_dr7(i, breakinfo[i].len, + breakinfo[i].type); + else + arch_uninstall_hw_breakpoint(bp); bp->attr.disabled = 1; } } @@ -379,6 +400,11 @@ void kgdb_disable_hw_debug(struct pt_regs *regs) for (i = 0; i < 4; i++) { if (!breakinfo[i].enabled) continue; + if (dbg_is_early) { + early_dr7 &= ~encode_dr7(i, breakinfo[i].len, + breakinfo[i].type); + continue; + } bp = *per_cpu_ptr(breakinfo[i].pev, cpu); if (bp->attr.disabled == 1) continue; @@ -595,15 +621,16 @@ static struct notifier_block kgdb_notifier = { * specific callbacks. */ int kgdb_arch_init(void) +{ + return register_die_notifier(&kgdb_notifier); +} + +void kgdb_arch_late(void) { int i, cpu; - int ret; struct perf_event_attr attr; struct perf_event **pevent; - ret = register_die_notifier(&kgdb_notifier); - if (ret != 0) - return ret; /* * Pre-allocate the hw breakpoint structions in the non-atomic * portion of kgdb because this operation requires mutexs to @@ -615,12 +642,15 @@ int kgdb_arch_init(void) attr.bp_type = HW_BREAKPOINT_W; attr.disabled = 1; for (i = 0; i < 4; i++) { + if (breakinfo[i].pev) + continue; breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL); if (IS_ERR(breakinfo[i].pev)) { - printk(KERN_ERR "kgdb: Could not allocate hw breakpoints\n"); + printk(KERN_ERR "kgdb: Could not allocate hw" + "breakpoints\nDisabling the kernel debugger\n"); breakinfo[i].pev = NULL; kgdb_arch_exit(); - return -1; + return; } for_each_online_cpu(cpu) { pevent = per_cpu_ptr(breakinfo[i].pev, cpu); @@ -631,7 +661,6 @@ int kgdb_arch_init(void) } } } - return ret; } /** diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index c4851eff57b32ce96e5bc2e72f536d01a6a78fb8..e8029896309af8cadb39b2445568d8c3ddc410ae 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -725,6 +725,7 @@ void __init setup_arch(char **cmdline_p) /* VMI may relocate the fixmap; do this before touching ioremap area */ vmi_init(); + early_trap_init(); early_cpu_init(); early_ioremap_init(); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 7eaad4c5110a15934bc24b162acb274a85bf82c7..142d70c74b027c31512c02dafea1e510d686a2fb 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -808,6 +808,16 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) } #endif +/* Set of traps needed for early debugging. */ +void __init early_trap_init(void) +{ + set_intr_gate_ist(1, &debug, DEBUG_STACK); + /* int3 can be called from all */ + set_system_intr_gate_ist(3, &int3, DEBUG_STACK); + set_intr_gate(14, &page_fault); + load_idt(&idt_descr); +} + void __init trap_init(void) { int i; @@ -821,10 +831,7 @@ void __init trap_init(void) #endif set_intr_gate(0, ÷_error); - set_intr_gate_ist(1, &debug, DEBUG_STACK); set_intr_gate_ist(2, &nmi, NMI_STACK); - /* int3 can be called from all */ - set_system_intr_gate_ist(3, &int3, DEBUG_STACK); /* int4 can be called from all */ set_system_intr_gate(4, &overflow); set_intr_gate(5, &bounds); @@ -840,7 +847,6 @@ void __init trap_init(void) set_intr_gate(11, &segment_not_present); set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK); set_intr_gate(13, &general_protection); - set_intr_gate(14, &page_fault); set_intr_gate(15, &spurious_interrupt_bug); set_intr_gate(16, &coprocessor_error); set_intr_gate(17, &alignment_check); diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c index b765ab48dfe7aa9d1f9b771335e34e4c5695f14d..a9a94ae7234951f3b30b25829c67d1ee13a3a8f2 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -223,6 +223,25 @@ static struct kgdb_io kgdboc_io_ops = { .post_exception = kgdboc_post_exp_handler, }; +#ifdef CONFIG_KGDB_SERIAL_CONSOLE +/* This is only available if kgdboc is a built in for early debugging */ +int __init kgdboc_early_init(char *opt) +{ + /* save the first character of the config string because the + * init routine can destroy it. + */ + char save_ch; + + kgdboc_option_setup(opt); + save_ch = config[0]; + init_kgdboc(); + config[0] = save_ch; + return 0; +} + +early_param("ekgdboc", kgdboc_early_init); +#endif /* CONFIG_KGDB_SERIAL_CONSOLE */ + module_init(init_kgdboc); module_exit(cleanup_kgdboc); module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index 6e98a369784473e08ab9efaa462de09a86ba8b8c..94ecdbc758ce60810cf176c0fdd479106b80bcdc 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -19,6 +19,9 @@ #include #include #include +#include +#include +#include #include #include #include @@ -55,6 +58,7 @@ static struct ehci_regs __iomem *ehci_regs; static struct ehci_dbg_port __iomem *ehci_debug; static int dbgp_not_safe; /* Cannot use debug device during ehci reset */ static unsigned int dbgp_endpoint_out; +static unsigned int dbgp_endpoint_in; struct ehci_dev { u32 bus; @@ -91,6 +95,13 @@ static inline u32 dbgp_len_update(u32 x, u32 len) return (x & ~0x0f) | (len & 0x0f); } +#ifdef CONFIG_KGDB +static struct kgdb_io kgdbdbgp_io_ops; +#define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops) +#else +#define dbgp_kgdb_mode (0) +#endif + /* * USB Packet IDs (PIDs) */ @@ -182,11 +193,10 @@ static void dbgp_breath(void) /* Sleep to give the debug port a chance to breathe */ } -static int dbgp_wait_until_done(unsigned ctrl) +static int dbgp_wait_until_done(unsigned ctrl, int loop) { u32 pids, lpid; int ret; - int loop = DBGP_LOOPS; retry: writel(ctrl | DBGP_GO, &ehci_debug->control); @@ -276,13 +286,13 @@ static int dbgp_bulk_write(unsigned devnum, unsigned endpoint, dbgp_set_data(bytes, size); writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); return ret; } static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, - int size) + int size, int loops) { u32 pids, addr, ctrl; int ret; @@ -302,7 +312,7 @@ static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, loops); if (ret < 0) return ret; @@ -343,12 +353,12 @@ static int dbgp_control_msg(unsigned devnum, int requesttype, dbgp_set_data(&req, sizeof(req)); writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - ret = dbgp_wait_until_done(ctrl); + ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS); if (ret < 0) return ret; /* Read the result */ - return dbgp_bulk_read(devnum, 0, data, size); + return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS); } /* Find a PCI capability */ @@ -559,6 +569,7 @@ int dbgp_external_startup(void) goto err; } dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint; + dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint; /* Move the device to 127 if it isn't already there */ if (devnum != USB_DEBUG_DEVNUM) { @@ -968,8 +979,9 @@ int dbgp_reset_prep(void) if (!ehci_debug) return 0; - if (early_dbgp_console.index != -1 && - !(early_dbgp_console.flags & CON_BOOT)) + if ((early_dbgp_console.index != -1 && + !(early_dbgp_console.flags & CON_BOOT)) || + dbgp_kgdb_mode) return 1; /* This means the console is not initialized, or should get * shutdown so as to allow for reuse of the usb device, which @@ -982,3 +994,93 @@ int dbgp_reset_prep(void) return 0; } EXPORT_SYMBOL_GPL(dbgp_reset_prep); + +#ifdef CONFIG_KGDB + +static char kgdbdbgp_buf[DBGP_MAX_PACKET]; +static int kgdbdbgp_buf_sz; +static int kgdbdbgp_buf_idx; +static int kgdbdbgp_loop_cnt = DBGP_LOOPS; + +static int kgdbdbgp_read_char(void) +{ + int ret; + + if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) { + char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++]; + return ch; + } + + ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in, + &kgdbdbgp_buf, DBGP_MAX_PACKET, + kgdbdbgp_loop_cnt); + if (ret <= 0) + return NO_POLL_CHAR; + kgdbdbgp_buf_sz = ret; + kgdbdbgp_buf_idx = 1; + return kgdbdbgp_buf[0]; +} + +static void kgdbdbgp_write_char(u8 chr) +{ + early_dbgp_write(NULL, &chr, 1); +} + +static struct kgdb_io kgdbdbgp_io_ops = { + .name = "kgdbdbgp", + .read_char = kgdbdbgp_read_char, + .write_char = kgdbdbgp_write_char, +}; + +static int kgdbdbgp_wait_time; + +static int __init kgdbdbgp_parse_config(char *str) +{ + char *ptr; + + if (!ehci_debug) { + if (early_dbgp_init(str)) + return -1; + } + ptr = strchr(str, ','); + if (ptr) { + ptr++; + kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10); + } + kgdb_register_io_module(&kgdbdbgp_io_ops); + kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1; + + return 0; +} +early_param("kgdbdbgp", kgdbdbgp_parse_config); + +static int kgdbdbgp_reader_thread(void *ptr) +{ + int ret; + + while (readl(&ehci_debug->control) & DBGP_ENABLED) { + kgdbdbgp_loop_cnt = 1; + ret = kgdbdbgp_read_char(); + kgdbdbgp_loop_cnt = DBGP_LOOPS; + if (ret != NO_POLL_CHAR) { + if (ret == 0x3 || ret == '$') { + if (ret == '$') + kgdbdbgp_buf_idx--; + kgdb_breakpoint(); + } + continue; + } + schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ); + } + return 0; +} + +static int __init kgdbdbgp_start_thread(void) +{ + if (dbgp_kgdb_mode && kgdbdbgp_wait_time) + kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp"); + + return 0; +} +module_init(kgdbdbgp_start_thread); +#endif /* CONFIG_KGDB */ diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 6c784ab6856ac006803c52d7d064595262caf345..9340f34d1bb5e7af04ad247d119d341e9d5cd0a6 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -207,6 +207,17 @@ 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); +/** + * kgdb_arch_late - Perform any architecture specific initalization. + * + * This function will handle the late initalization of any + * architecture specific callbacks. This is an optional function for + * handling things like late initialization of hw breakpoints. The + * default implementation does nothing. + */ +extern void kgdb_arch_late(void); + + /** * struct kgdb_arch - Describe architecture specific values. * @gdb_bpt_instr: The instruction to trigger a breakpoint. @@ -285,7 +296,10 @@ extern int kgdb_single_step; extern atomic_t kgdb_active; #define in_dbg_master() \ (raw_smp_processor_id() == atomic_read(&kgdb_active)) +extern bool dbg_is_early; +extern void __init dbg_late_init(void); #else /* ! CONFIG_KGDB */ #define in_dbg_master() (0) +#define dbg_late_init() #endif /* ! CONFIG_KGDB */ #endif /* _KGDB_H_ */ diff --git a/init/main.c b/init/main.c index 372771333d983d1eb692032ac47db70ef080924c..22881b5e95e3b00e010b407310539fbd4e1a8a57 100644 --- a/init/main.c +++ b/init/main.c @@ -62,7 +62,7 @@ #include #include #include -#include +#include #include #include #include @@ -676,7 +676,7 @@ asmlinkage void __init start_kernel(void) buffer_init(); key_init(); security_init(); - kdb_init(KDB_INIT_FULL); + dbg_late_init(); vfs_caches_init(totalram_pages); signals_init(); /* rootfs populating might need page-writeback */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 64b5588c96389228c01dca2932c0fb9625ca18a8..5cb7cd1de10c7dd5b3380f69d49854cb539a4011 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -78,6 +78,8 @@ static DEFINE_SPINLOCK(kgdb_registration_lock); static int kgdb_con_registered; /* determine if kgdb console output should be used */ static int kgdb_use_con; +/* Flag for alternate operations for early debugging */ +bool dbg_is_early = true; /* Next cpu to become the master debug core */ int dbg_switch_cpu; @@ -777,11 +779,25 @@ static struct notifier_block kgdb_panic_event_nb = { .priority = INT_MAX, }; +void __weak kgdb_arch_late(void) +{ +} + +void __init dbg_late_init(void) +{ + dbg_is_early = false; + if (kgdb_io_module_registered) + kgdb_arch_late(); + kdb_init(KDB_INIT_FULL); +} + static void kgdb_register_callbacks(void) { if (!kgdb_io_module_registered) { kgdb_io_module_registered = 1; kgdb_arch_init(); + if (!dbg_is_early) + kgdb_arch_late(); atomic_notifier_chain_register(&panic_notifier_list, &kgdb_panic_event_nb); #ifdef CONFIG_MAGIC_SYSRQ