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i've uploaded kgdb-light -v9, it can be pulled from: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-kgdb.git find the shortlog, diffstat, full patch below. There are a number of changes in -v9 - a patch from Jason to clean up kernel-messages-over-the-kgdb-console behavior and a bugfix from Jan. Here's how i addressed the review feedback from Andi Kleen:fixed. (That code is gone now - the pt_regs passed in to the notifier points to the right kind of register context already, so the whole shadow task business on 64-bit was an unnecessary complication - as you suspected it. With it went another bunch of kernel/kgdb.c complication as well.) i reworked and cleaned up all the kgdb locking code completely. No more NR_CPUS spinlocks, there's now proper use of barriers, etc. No more silly "timeouts" for locking either ... There's now a very well-defined and clean locking state-machine for the primary CPU and the secondary CPUs. I re-tested it all on SMP hardware as well. i fixed the shadow thread bits which where harmless but unnecessary. exotic indeed - but nevertheless i fixed this too. previously Mark indicated some sort of sprintf return value breakage he observed, and kgdb would rely on sprintf return values so i'm inclined to leave it as-is. We can fix that later, it's not critical. i fixed them too. thanks for your suggestions, anything else you can think of? Ingo ------------------> Ingo Molnar (3): pids: add pid_max prototype uaccess: add probe_kernel_write() x86: kgdb support Jason Wessel (3): kgdb: core consoles: polling support, kgdboc kgdb: document parameters Documentation/kernel-parameters.txt | 5 + arch/x86/Kconfig | 1 + arch/x86/kernel/Makefile | 1 + arch/x86/kernel/kgdb.c | 555 ++++++++++++ drivers/char/tty_io.c | 47 + drivers/serial/8250.c | 58 ++ drivers/serial/Kconfig | 3 + drivers/serial/Makefile | 1 + drivers/serial/kgdboc.c | 163 ++++ drivers/serial/serial_core.c | 70 ++- include/asm-x86/kgdb.h | 81 ++ include/linux/kgdb.h | 271 ++++++ include/linux/pid.h | 2 + include/linux/serial_core.h | 4 + include/linux/tty_driver.h | 12 + include/linux/uaccess.h | 22 + kernel/Makefile | 1 + kernel/kgdb.c | 1663 +++++++++++++++++++++++++++++++++++ kernel/sysctl.c | 2 +- lib/Kconfig.debug | 2 + lib/Kconfig.kgdb | 27 + mm/Makefile | 2 +- mm/maccess.c | 49 + 23 files changed, 3037 insertions(+), 5 deletions(-) create mode 100644 arch/x86/kernel/kgdb.c create mode 100644 drivers/serial/kgdboc.c create mode 100644 include/asm-x86/kgdb.h create mode 100644 include/linux/kgdb.h create mode 100644 kernel/kgdb.c create mode 100644 lib/Kconfig.kgdb create mode 100644 mm/maccess.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a4fc7fc..6e97307 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -930,6 +930,11 @@ and is between 256 and 4096 characters. It is defined in the file kstack=N [X86-32,X86-64] Print N words from the kernel stack in oops dumps. + kgdboc= [HW] kgdb over consoles. + Requires a tty driver that supports console polling. + (only serial suported for now) + Format: <serial_device>[,baud] + l2cr= [PPC] lapic [X86-32,APIC] Enable the local APIC even if BIOS diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index aaed1a3..c8dd8f9 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -21,6 +21,7 @@ config X86 select HAVE_IDE select HAVE_OPROFILE select HAVE_KPROBES + select HAVE_ARCH_KGDB config GENERIC_LOCKBREAK def_bool n diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 76ec0f8..4cd39cd 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -58,6 +58,7 @@ obj-$(CONFIG_MODULES) += module_$(BITS).o obj-$(CONFIG_ACPI_SRAT) += srat_32.o obj-$(CONFIG_EFI) += efi.o efi_$(BITS).o efi_stub_$(BITS).o obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_VM86) += vm86_32.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c new file mode 100644 index 0000000..18034d5 --- /dev/null +++ b/arch/x86/kernel/kgdb.c @@ -0,0 +1,555 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * 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. + * + */ + +/* + * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com> + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002 Andi Kleen, SuSE Labs + * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc. + */ +/**************************************************************************** + * Contributor: Lake Stevens Instrument Division$ + * Written by: Glenn Engel $ + * Updated by: Amit Kale<akale@veritas.com> + * Updated by: Tom Rini <trini@kernel.crashing.org> + * Updated by: Jason Wessel <jason.wessel@windriver.com> + * Modified for 386 by Jim Kingdon, Cygnus Support. + * Origianl kgdb, compatibility with 2.1.xx kernel by + * David Grothe <dave@gcom.com> + * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com> + * X86_64 changes from Andi Kleen's patch merged by Jim Houston + */ +#include <linux/spinlock.h> +#include <linux/kdebug.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/ptrace.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/kgdb.h> +#include <linux/init.h> +#include <linux/smp.h> + +#include <asm/apicdef.h> +#include <asm/system.h> + +#ifdef CONFIG_X86_32 +# include <mach_ipi.h> +#else +# include <asm/mach_apic.h> +#endif + +/* + * Put the error code here just in case the user cares: + */ +static int gdb_x86errcode; + +/* + * Likewise, the vector number here (since GDB only gets the signal + * number through the usual means, and that's not very specific): + */ +static int gdb_x86vector = -1; + +/** + * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @regs: The &struct pt_regs of the current process. + * + * Convert the pt_regs in @regs into the format for registers that + * GDB expects, stored in @gdb_regs. + */ +void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + gdb_regs[GDB_AX] = regs->ax; + gdb_regs[GDB_BX] = regs->bx; + gdb_regs[GDB_CX] = regs->cx; + gdb_regs[GDB_DX] = regs->dx; + gdb_regs[GDB_SI] = regs->si; + gdb_regs[GDB_DI] = regs->di; + gdb_regs[GDB_BP] = regs->bp; + gdb_regs[GDB_PS] = regs->flags; + gdb_regs[GDB_PC] = regs->ip; +#ifdef CONFIG_X86_32 + gdb_regs[GDB_DS] = regs->ds; + gdb_regs[GDB_ES] = regs->es; + gdb_regs[GDB_CS] = regs->cs; + gdb_regs[GDB_SS] = __KERNEL_DS; + gdb_regs[GDB_FS] = 0xFFFF; + gdb_regs[GDB_GS] = 0xFFFF; +#else + gdb_regs[GDB_R8] = regs->r8; + gdb_regs[GDB_R9] = regs->r9; + gdb_regs[GDB_R10] = regs->r10; + gdb_regs[GDB_R11] = regs->r11; + gdb_regs[GDB_R12] = regs->r12; + gdb_regs[GDB_R13] = regs->r13; + gdb_regs[GDB_R14] = regs->r14; + gdb_regs[GDB_R15] = regs->r15; +#endif + gdb_regs[GDB_SP] = regs->sp; +} + +/** + * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @p: The &struct task_struct of the desired process. + * + * Convert the register values of the sleeping process in @p to + * the format that GDB expects. + * This function is called when kgdb does not have access to the + * &struct pt_regs and therefore it should fill the gdb registers + * @gdb_regs with what has been saved in &struct thread_struct + * thread field during switch_to. + */ +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + gdb_regs[GDB_AX] = 0; + gdb_regs[GDB_BX] = 0; + gdb_regs[GDB_CX] = 0; + gdb_regs[GDB_DX] = 0; + gdb_regs[GDB_SI] = 0; + gdb_regs[GDB_DI] = 0; + gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; +#ifdef CONFIG_X86_32 + gdb_regs[GDB_DS] = __KERNEL_DS; + gdb_regs[GDB_ES] = __KERNEL_DS; + gdb_regs[GDB_PS] = 0; + gdb_regs[GDB_CS] = __KERNEL_CS; + gdb_regs[GDB_PC] = p->thread.ip; + gdb_regs[GDB_SS] = __KERNEL_DS; + gdb_regs[GDB_FS] = 0xFFFF; + gdb_regs[GDB_GS] = 0xFFFF; +#else + gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8); + gdb_regs[GDB_PC] = 0; + gdb_regs[GDB_R8] = 0; + gdb_regs[GDB_R9] = 0; + gdb_regs[GDB_R10] = 0; + gdb_regs[GDB_R11] = 0; + gdb_regs[GDB_R12] = 0; + gdb_regs[GDB_R13] = 0; + gdb_regs[GDB_R14] = 0; + gdb_regs[GDB_R15] = 0; +#endif + gdb_regs[GDB_SP] = p->thread.sp; +} + +/** + * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. + * @gdb_regs: A pointer to hold the registers we've received from GDB. + * @regs: A pointer to a &struct pt_regs to hold these values in. + * + * Convert the GDB regs in @gdb_regs into the pt_regs, and store them + * in @regs. + */ +void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) +{ + regs->ax = gdb_regs[GDB_AX]; + regs->bx = gdb_regs[GDB_BX]; + regs->cx = gdb_regs[GDB_CX]; + regs->dx = gdb_regs[GDB_DX]; + regs->si = gdb_regs[GDB_SI]; + regs->di = gdb_regs[GDB_DI]; + regs->bp = gdb_regs[GDB_BP]; + regs->flags = gdb_regs[GDB_PS]; + regs->ip = gdb_regs[GDB_PC]; +#ifdef CONFIG_X86_32 + regs->ds = gdb_regs[GDB_DS]; + regs->es = gdb_regs[GDB_ES]; + regs->cs = gdb_regs[GDB_CS]; +#else + regs->r8 = gdb_regs[GDB_R8]; + regs->r9 = gdb_regs[GDB_R9]; + regs->r10 = gdb_regs[GDB_R10]; + regs->r11 = gdb_regs[GDB_R11]; + regs->r12 = gdb_regs[GDB_R12]; + regs->r13 = gdb_regs[GDB_R13]; + regs->r14 = gdb_regs[GDB_R14]; + regs->r15 = gdb_regs[GDB_R15]; +#endif +} + +static struct hw_breakpoint { + unsigned enabled; + unsigned type; + unsigned len; + unsigned long addr; +} breakinfo[4]; + +static void kgdb_correct_hw_break(void) +{ + unsigned long dr7; + int correctit = 0; + int breakbit; + int breakno; + + get_debugreg(dr7, 7); + for (breakno = 0; breakno < 4; breakno++) { + breakbit = 2 << (breakno << 1); + if (!(dr7 & breakbit) && breakinfo[breakno].enabled) { + correctit = 1; + dr7 |= breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + dr7 |= ((breakinfo[breakno].len << 2) | + breakinfo[breakno].type) << + ((breakno << 2) + 16); + if (breakno >= 0 && breakno <= 3) + set_debugreg(breakinfo[breakno].addr, breakno); + + } else { + if ((dr7 & breakbit) && !breakinfo[breakno].enabled) { + correctit = 1; + dr7 &= ~breakbit; + dr7 &= ~(0xf0000 << (breakno << 2)); + } + } + } + if (correctit) + set_debugreg(dr7, 7); +} + +static int +kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) +{ + int i; + + for (i = 0; i < 4; i++) + if (breakinfo[i].addr == addr && breakinfo[i].enabled) + break; + if (i == 4) + return -1; + + breakinfo[i].enabled = 0; + + return 0; +} + +static void kgdb_remove_all_hw_break(void) +{ + int i; + + for (i = 0; i < 4; i++) + memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint)); +} + +static int +kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) +{ + unsigned type; + int i; + + for (i = 0; i < 4; i++) + if (!breakinfo[i].enabled) + break; + if (i == 4) + return -1; + + switch (bptype) { + case BP_HARDWARE_BREAKPOINT: + type = 0; + len = 1; + break; + case BP_WRITE_WATCHPOINT: + type = 1; + break; + case BP_ACCESS_WATCHPOINT: + type = 3; + break; + default: + return -1; + } + + if (len == 1 || len == 2 || len == 4) + breakinfo[i].len = len - 1; + else + return -1; + + breakinfo[i].enabled = 1; + breakinfo[i].addr = addr; + breakinfo[i].type = type; + + return 0; +} + +/** + * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +void kgdb_disable_hw_debug(struct pt_regs *regs) +{ + /* Disable hardware debugging while we are in kgdb: */ + set_debugreg(0UL, 7); +} + +/** + * kgdb_post_primary_code - Save error vector/code numbers. + * @regs: Original pt_regs. + * @e_vector: Original error vector. + * @err_code: Original error code. + * + * This is needed on architectures which support SMP and KGDB. + * This function is called after all the slave cpus have been put + * to a know spin state and the primary CPU has control over KGDB. + */ +void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) +{ + /* primary processor is completely in the debugger */ + gdb_x86vector = e_vector; + gdb_x86errcode = err_code; +} + +#ifdef CONFIG_SMP +/** + * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * @flags: Current IRQ state + * + * On SMP systems, we need to get the attention of the other CPUs + * and get them be in a known state. This should do what is needed + * to get the other CPUs to call kgdb_wait(). Note that on some arches, + * the NMI approach is not used for rounding up all the CPUs. For example, + * in case of MIPS, smp_call_function() is used to roundup CPUs. In + * this case, we have to make sure that interrupts are enabled before + * calling smp_call_function(). The argument to this function is + * the flags that will be used when restoring the interrupts. There is + * local_irq_save() call before kgdb_roundup_cpus(). + * + * On non-SMP systems, this is not called. + */ +void kgdb_roundup_cpus(unsigned long flags) +{ + send_IPI_allbutself(APIC_DM_NMI); +} +#endif + +/** + * kgdb_arch_handle_exception - Handle architecture specific GDB packets. + * @vector: The error vector of the exception that happened. + * @signo: The signal number of the exception that happened. + * @err_code: The error code of the exception that happened. + * @remcom_in_buffer: The buffer of the packet we have read. + * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. + * @regs: The &struct pt_regs of the current process. + * + * This function MUST handle the 'c' and 's' command packets, + * as well packets to set / remove a hardware breakpoint, if used. + * If there are additional packets which the hardware needs to handle, + * they are handled here. The code should return -1 if it wants to + * process more packets, and a %0 or %1 if it wants to exit from the + * kgdb callback. + */ +int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, + char *remcomInBuffer, char *remcomOutBuffer, + struct pt_regs *linux_regs) +{ + unsigned long addr; + unsigned long dr6; + char *ptr; + int newPC; + + switch (remcomInBuffer[0]) { + case 'c': + case 's': + /* try to read optional parameter, pc unchanged if no parm */ + ptr = &remcomInBuffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + linux_regs->ip = addr; + newPC = linux_regs->ip; + + /* clear the trace bit */ + linux_regs->flags &= ~TF_MASK; + atomic_set(&kgdb_cpu_doing_single_step, -1); + + /* set the trace bit if we're stepping */ + if (remcomInBuffer[0] == 's') { + linux_regs->flags |= TF_MASK; + kgdb_single_step = 1; + if (kgdb_contthread) { + atomic_set(&kgdb_cpu_doing_single_step, + raw_smp_processor_id()); + } + } + + get_debugreg(dr6, 6); + if (!(dr6 & 0x4000)) { + int breakno; + + for (breakno = 0; breakno < 4; breakno++) { + if (dr6 & (1 << breakno) && + breakinfo[breakno].type == 0) { + /* Set restore flag: */ + linux_regs->flags |= X86_EFLAGS_RF; + break; + } + } + } + set_debugreg(0UL, 6); + kgdb_correct_hw_break(); + + return 0; + } + + /* this means that we do not want to exit from the handler: */ + return -1; +} + +static inline int +single_step_cont(struct pt_regs *regs, struct die_args *args) +{ + /* + * Single step exception from kernel space to user space so + * eat the exception and continue the process: + */ + printk(KERN_ERR "KGDB: trap/step from kernel to user space, " + "resuming...\n"); + kgdb_arch_handle_exception(args->trapnr, args->signr, + args->err, "c", "", regs); + + return NOTIFY_STOP; +} + +static int __kgdb_notify(struct die_args *args, unsigned long cmd) +{ + struct pt_regs *regs = args->regs; + + switch (cmd) { + case DIE_NMI: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup */ + kgdb_nmicallback(raw_smp_processor_id(), regs); + return NOTIFY_STOP; + } + return NOTIFY_DONE; + + case DIE_NMI_IPI: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup: */ + if (kgdb_nmicallback(raw_smp_processor_id(), regs)) + return NOTIFY_DONE; + return NOTIFY_STOP; + } + return NOTIFY_DONE; + + case DIE_NMIWATCHDOG: + if (atomic_read(&kgdb_active) != -1) { + /* KGDB CPU roundup: */ + kgdb_nmicallback(raw_smp_processor_id(), regs); + return NOTIFY_STOP; + } + /* Enter debugger: */ + break; + + case DIE_DEBUG: + if (atomic_read(&kgdb_cpu_doing_single_step) == + raw_smp_processor_id() && + user_mode(regs)) + return single_step_cont(regs, args); + /* fall through */ + default: + if (user_mode(regs)) + return NOTIFY_DONE; + } + + if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) + return NOTIFY_DONE; + + return NOTIFY_STOP; +} + +static int +kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) +{ + unsigned long flags; + int ret; + + local_irq_save(flags); + ret = __kgdb_notify(ptr, cmd); + local_irq_restore(flags); + + return ret; +} + +static struct notifier_block kgdb_notifier = { + .notifier_call = kgdb_notify, + + /* + * Lowest-prio notifier priority, we want to be notified last: + */ + .priority = -INT_MAX, +}; + +/** + * kgdb_arch_init - Perform any architecture specific initalization. + * + * This function will handle the initalization of any architecture + * specific callbacks. + */ +int kgdb_arch_init(void) +{ + return register_die_notifier(&kgdb_notifier); +} + +/** + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +void kgdb_arch_exit(void) +{ + unregister_die_notifier(&kgdb_notifier); +} + +/** + * + * kgdb_skipexception - Bail of of KGDB when we've been triggered. + * @exception: Exception vector number + * @regs: Current &struct pt_regs. + * + * On some architectures we need to skip a breakpoint exception when + * it occurs after a breakpoint has been removed. + * + * Skip an int3 exception when it occurs after a breakpoint has been + * removed. Backtrack eip by 1 since the int3 would have caused it to + * increment by 1. + */ +int kgdb_skipexception(int exception, struct pt_regs *regs) +{ + if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) { + regs->ip -= 1; + return 1; + } + return 0; +} + +unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + if (exception == 3) + return instruction_pointer(regs) - 1; + return instruction_pointer(regs); +} + +struct kgdb_arch arch_kgdb_ops = { + /* Breakpoint instruction: */ + .gdb_bpt_instr = { 0xcc }, + .flags = KGDB_HW_BREAKPOINT, + .set_hw_breakpoint = kgdb_set_hw_break, + .remove_hw_breakpoint = kgdb_remove_hw_break, + .remove_all_hw_break = kgdb_remove_all_hw_break, + .correct_hw_break = kgdb_correct_hw_break, +}; diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 613ec81..4d3c701 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -1155,6 +1155,48 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) return NULL; } +#ifdef CONFIG_CONSOLE_POLL + +/** + * tty_find_polling_driver - find device of a polled tty + * @name: name string to match + * @line: pointer to resulting tty line nr + * + * This routine returns a tty driver structure, given a name + * and the condition that the tty driver is capable of polled + * operation. + */ +struct tty_driver *tty_find_polling_driver(char *name, int *line) +{ + struct tty_driver *p, *res = NULL; + int tty_line = 0; + char *str; + + mutex_lock(&tty_mutex); + /* Search through the tty devices to look for a match */ + list_for_each_entry(p, &tty_drivers, tty_drivers) { + str = name + strlen(p->name); + tty_line = simple_strtoul(str, &str, 10); + if (*str == ',') + str++; + if (*str == '\0') + str = 0; + + if (tty_line >= 0 && tty_line <= p->num && p->poll_init && + !p->poll_init(p, tty_line, str)) { + + res = p; + *line = tty_line; + break; + } + } + mutex_unlock(&tty_mutex); + + return res; +} +EXPORT_SYMBOL_GPL(tty_find_polling_driver); +#endif + /** * tty_check_change - check for POSIX terminal changes * @tty: tty to check @@ -3850,6 +3892,11 @@ void tty_set_operations(struct tty_driver *driver, driver->write_proc = op->write_proc; driver->tiocmget = op->tiocmget; driver->tiocmset = op->tiocmset; +#ifdef CONFIG_CONSOLE_POLL + driver->poll_init = op->poll_init; + driver->poll_get_char = op->poll_get_char; + driver->poll_put_char = op->poll_put_char; +#endif } diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 77f7a7f..96a585e 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1740,6 +1740,60 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits) } } +#ifdef CONFIG_CONSOLE_POLL +/* + * Console polling routines for writing and reading from the uart while + * in an interrupt or debug context. + */ + +static int serial8250_get_poll_char(struct uart_port *port) +{ + struct uart_8250_port *up = (struct uart_8250_port *)port; + unsigned char lsr = serial_inp(up, UART_LSR); + + while (!(lsr & UART_LSR_DR)) + lsr = serial_inp(up, UART_LSR); + + return serial_inp(up, UART_RX); +} + + +static void serial8250_put_poll_char(struct uart_port *port, + unsigned char c) +{ + unsigned int ier; + struct uart_8250_port *up = (struct uart_8250_port *)port; + + /* + * First save the IER then disable the interrupts + */ + ier = serial_in(up, UART_IER); + if (up->capabilities & UART_CAP_UUE) + serial_out(up, UART_IER, UART_IER_UUE); + else + serial_out(up, UART_IER, 0); + + wait_for_xmitr(up, BOTH_EMPTY); + /* + * Send the character out. + * If a LF, also do CR... + */ + serial_out(up, UART_TX, c); + if (c == 10) { + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_TX, 13); + } + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up, BOTH_EMPTY); + serial_out(up, UART_IER, ier); +} + +#endif /* CONFIG_CONSOLE_POLL */ + static int serial8250_startup(struct uart_port *port) { struct uart_8250_port *up = (struct uart_8250_port *)port; @@ -2386,6 +2440,10 @@ static struct uart_ops serial8250_pops = { .request_port = serial8250_request_port, .config_port = serial8250_config_port, .verify_port = serial8250_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = serial8250_get_poll_char, + .poll_put_char = serial8250_put_poll_char, +#endif }; static struct uart_8250_port serial8250_ports[UART_NR]; diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index b82595c..5d9667c 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -961,6 +961,9 @@ config SERIAL_CORE config SERIAL_CORE_CONSOLE bool +config CONSOLE_POLL + bool + config SERIAL_68328 bool "68328 serial support" depends on M68328 || M68EZ328 || M68VZ328 diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 640cfe4..3cbea54 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -66,4 +66,5 @@ obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o obj-$(CONFIG_SERIAL_NETX) += netx-serial.o obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o +obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o obj-$(CONFIG_SERIAL_QE) += ucc_uart.o diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c new file mode 100644 index 0000000..3418307 --- /dev/null +++ b/drivers/serial/kgdboc.c @@ -0,0 +1,163 @@ +/* + * Based on the same principle as kgdboe using the NETPOLL api, this + * driver uses a console polling api to implement a gdb serial inteface + * which is multiplexed on a console port. + * + * Maintainer: Jason Wessel <jason.wessel@windriver.com> + * + * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ +#include <linux/kernel.h> +#include <linux/ctype.h> +#include <linux/kgdb.h> +#include <linux/tty.h> + +#define MAX_CONFIG_LEN 40 + +static struct kgdb_io kgdboc_io_ops; + +/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ +static int configured = -1; + +static char config[MAX_CONFIG_LEN]; +static struct kparam_string kps = { + .string = config, + .maxlen = MAX_CONFIG_LEN, +}; + +static struct tty_driver *kgdb_tty_driver; +static int kgdb_tty_line; + +static int kgdboc_option_setup(char *opt) +{ + if (strlen(opt) > MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdboc: config string too long\n"); + return -ENOSPC; + } + strcpy(config, opt); + + return 0; +} + +__setup("kgdboc=", kgdboc_option_setup); + +static int configure_kgdboc(void) +{ + struct tty_driver *p; + int tty_line = 0; + int err; + + err = kgdboc_option_setup(config); + if (err || !strlen(config) || isspace(config[0])) + goto noconfig; + + err = -ENODEV; + + p = tty_find_polling_driver(config, &tty_line); + if (!p) + goto noconfig; + + kgdb_tty_driver = p; + kgdb_tty_line = tty_line; + + err = kgdb_register_io_module(&kgdboc_io_ops); + if (err) + goto noconfig; + + configured = 1; + + return 0; + +noconfig: + config[0] = 0; + configured = 0; + + return err; +} + +static int __init init_kgdboc(void) +{ + /* Already configured? */ + if (configured == 1) + return 0; + + return configure_kgdboc(); +} + +static void cleanup_kgdboc(void) +{ + if (configured == 1) + kgdb_unregister_io_module(&kgdboc_io_ops); +} + +static int kgdboc_get_char(void) +{ + return kgdb_tty_driver->poll_get_char(kgdb_tty_driver, kgdb_tty_line); +} + +static void kgdboc_put_char(u8 chr) +{ + kgdb_tty_driver->poll_put_char(kgdb_tty_driver, kgdb_tty_line, chr); +} + +static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) +{ + if (strlen(kmessage) >= MAX_CONFIG_LEN) { + printk(KERN_ERR "kgdboc: 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 (kgdb_connected) { + printk(KERN_ERR + "kgdboc: Cannot reconfigure while KGDB is connected.\n"); + + return -EBUSY; + } + + strcpy(config, kmessage); + + if (configured == 1) + cleanup_kgdboc(); + + /* Go and configure with the new params. */ + return configure_kgdboc(); +} + +static void kgdboc_pre_exp_handler(void) +{ + /* Increment the module count when the debugger is active */ + if (!kgdb_connected) + try_module_get(THIS_MODULE); +} + +static void kgdboc_post_exp_handler(void) +{ + /* decrement the module count when the debugger detaches */ + if (!kgdb_connected) + module_put(THIS_MODULE); +} + +static struct kgdb_io kgdboc_io_ops = { + .name = "kgdboc", + .read_char = kgdboc_get_char, + .write_char = kgdboc_put_char, + .pre_exception = kgdboc_pre_exp_handler, + .post_exception = kgdboc_post_exp_handler, +}; + +module_init(init_kgdboc); +module_exit(cleanup_kgdboc); +module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); +MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]"); +MODULE_DESCRIPTION("KGDB Console TTY Driver"); +MODULE_LICENSE("GPL"); diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 0f5a179..cec193b 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -1827,7 +1827,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co) * options. The format of the string is <baud><parity><bits><flow>, * eg: 115200n8r */ -void __init +void uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) { char *s = options; @@ -1872,7 +1872,7 @@ static const struct baud_rates baud_rates[] = { * @bits: number of data bits * @flow: flow control character - 'r' (rts) */ -int __init +int uart_set_options(struct uart_port *port, struct console *co, int baud, int parity, int bits, int flow) { @@ -1924,7 +1924,12 @@ uart_set_options(struct uart_port *port, struct console *co, port->mctrl |= TIOCM_DTR; port->ops->set_termios(port, &termios, &dummy); - co->cflag = termios.c_cflag; + /* + * Allow the setting of the UART parameters with a NULL console + * too: + */ + if (co) + co->cflag = termios.c_cflag; return 0; } @@ -2182,6 +2187,60 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, } } +#ifdef CONFIG_CONSOLE_POLL + +static int uart_poll_init(struct tty_driver *driver, int line, char *options) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (!state || !state->port) + return -1; + + port = state->port; + if (!(port->ops->poll_get_char && port->ops->poll_put_char)) + return -1; + + if (options) { + uart_parse_options(options, &baud, &parity, &bits, &flow); + return uart_set_options(port, NULL, baud, parity, bits, flow); + } + + return 0; +} + +static int uart_poll_get_char(struct tty_driver *driver, int line) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + + if (!state || !state->port) + return -1; + + port = state->port; + return port->ops->poll_get_char(port); +} + +static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + line; + struct uart_port *port; + + if (!state || !state->port) + return; + + port = state->port; + port->ops->poll_put_char(port, ch); +} +#endif + static const struct tty_operations uart_ops = { .open = uart_open, .close = uart_close, @@ -2206,6 +2265,11 @@ static const struct tty_operations uart_ops = { #endif .tiocmget = uart_tiocmget, .tiocmset = uart_tiocmset, +#ifdef CONFIG_CONSOLE_POLL + .poll_init = uart_poll_init, + .poll_get_char = uart_poll_get_char, + .poll_put_char = uart_poll_put_char, +#endif }; /** diff --git a/include/asm-x86/kgdb.h b/include/asm-x86/kgdb.h new file mode 100644 index 0000000..484c475 --- /dev/null +++ b/include/asm-x86/kgdb.h @@ -0,0 +1,81 @@ +#ifndef _ASM_KGDB_H_ +#define _ASM_KGDB_H_ + +/* + * Copyright (C) 2001-2004 Amit S. Kale + * Copyright (C) 2008 Wind River Systems, Inc. + */ + +/* + * BUFMAX defines the maximum number of characters in inbound/outbound + * buffers at least NUMREGBYTES*2 are needed for register packets + * Longer buffer is needed to list all threads + */ +#define BUFMAX 1024 + +/* + * Note that this register image is in a different order than + * the register image that Linux produces at interrupt time. + * + * Linux's register image is defined by struct pt_regs in ptrace.h. + * Just why GDB uses a different order is a historical mystery. + */ +#ifdef CONFIG_X86_32 +enum regnames { + GDB_AX, /* 0 */ + GDB_CX, /* 1 */ + GDB_DX, /* 2 */ + GDB_BX, /* 3 */ + GDB_SP, /* 4 */ + GDB_BP, /* 5 */ + GDB_SI, /* 6 */ + GDB_DI, /* 7 */ + GDB_PC, /* 8 also known as eip */ + GDB_PS, /* 9 also known as eflags */ + GDB_CS, /* 10 */ + GDB_SS, /* 11 */ + GDB_DS, /* 12 */ + GDB_ES, /* 13 */ + GDB_FS, /* 14 */ + GDB_GS, /* 15 */ +}; +#else /* ! CONFIG_X86_32 */ +enum regnames { + GDB_AX, /* 0 */ + GDB_DX, /* 1 */ + GDB_CX, /* 2 */ + GDB_BX, /* 3 */ + GDB_SI, /* 4 */ + GDB_DI, /* 5 */ + GDB_BP, /* 6 */ + GDB_SP, /* 7 */ + GDB_R8, /* 8 */ + GDB_R9, /* 9 */ + GDB_R10, /* 10 */ + GDB_R11, /* 11 */ + GDB_R12, /* 12 */ + GDB_R13, /* 13 */ + GDB_R14, /* 14 */ + GDB_R15, /* 15 */ + GDB_PC, /* 16 */ + GDB_PS, /* 17 */ +}; +#endif /* CONFIG_X86_32 */ + +/* + * Number of bytes of registers: + */ +#ifdef CONFIG_X86_32 +# define NUMREGBYTES 64 +#else +# define NUMREGBYTES ((GDB_PS+1)*8) +#endif + +static inline void arch_kgdb_breakpoint(void) +{ + asm(" int $3"); +} +#define BREAK_INSTR_SIZE 1 +#define CACHE_FLUSH_IS_SAFE 1 + +#endif /* _ASM_KGDB_H_ */ diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h new file mode 100644 index 0000000..b2be3a8 --- /dev/null +++ b/include/linux/kgdb.h @@ -0,0 +1,271 @@ +/* + * This provides the callbacks and functions that KGDB needs to share between + * the core, I/O and arch-specific portions. + * + * Author: Amit Kale <amitkale@linsyssoft.com> and + * Tom Rini <trini@kernel.crashing.org> + * + * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc. + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#ifndef _KGDB_H_ +#define _KGDB_H_ + +#include <linux/serial_8250.h> +#include <linux/linkage.h> +#include <linux/init.h> + +#include <asm/atomic.h> +#include <asm/kgdb.h> + +struct pt_regs; + +/* + * kgdb_skipexception - Bail of of KGDB when we've been triggered. + * @exception: Exception vector number + * @regs: Current &struct pt_regs. + * + * On some architectures we need to skip a breakpoint exception when + * it occurs after a breakpoint has been removed. + */ +extern int kgdb_skipexception(int exception, struct pt_regs *regs); + +/* + * kgdb_post_primary_code - Save error vector/code numbers. + * @regs: Original pt_regs. + * @e_vector: Original error vector. + * @err_code: Original error code. + * + * This is needed on architectures which support SMP and KGDB. + * This function is called after all the secondary cpus have been put + * to a know spin state and the primary CPU has control over KGDB. + */ +extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, + int err_code); + +/* + * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. + * @regs: Current &struct pt_regs. + * + * This function will be called if the particular architecture must + * disable hardware debugging while it is processing gdb packets or + * handling exception. + */ +extern void kgdb_disable_hw_debug(struct pt_regs *regs); + +struct tasklet_struct; +struct task_struct; +struct uart_port; + +/* To enter the debugger explicitly. */ +void kgdb_breakpoint(void); + +extern int kgdb_connected; + +extern atomic_t kgdb_setting_breakpoint; +extern atomic_t kgdb_cpu_doing_single_step; + +extern struct task_struct *kgdb_usethread; +extern struct task_struct *kgdb_contthread; + +enum kgdb_bptype { + BP_BREAKPOINT = 0, + BP_HARDWARE_BREAKPOINT, + BP_WRITE_WATCHPOINT, + BP_READ_WATCHPOINT, + BP_ACCESS_WATCHPOINT +}; + +enum kgdb_bpstate { + BP_UNDEFINED = 0, + BP_REMOVED, + BP_SET, + BP_ACTIVE +}; + +struct kgdb_bkpt { + unsigned long bpt_addr; + unsigned char saved_instr[BREAK_INSTR_SIZE]; + enum kgdb_bptype type; + enum kgdb_bpstate state; +}; + +#ifndef KGDB_MAX_BREAKPOINTS +# define KGDB_MAX_BREAKPOINTS 1000 +#endif + +#define KGDB_HW_BREAKPOINT 1 + +/* + * Functions each KGDB-supporting architecture must provide: + */ + +/* + * kgdb_arch_init - Perform any architecture specific initalization. + * + * This function will handle the initalization of any architecture + * specific callbacks. + */ +extern int kgdb_arch_init(void); + +/* + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +extern void kgdb_arch_exit(void); + +/* + * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @regs: The &struct pt_regs of the current process. + * + * Convert the pt_regs in @regs into the format for registers that + * GDB expects, stored in @gdb_regs. + */ +extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); + +/* + * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs + * @gdb_regs: A pointer to hold the registers in the order GDB wants. + * @p: The &struct task_struct of the desired process. + * + * Convert the register values of the sleeping process in @p to + * the format that GDB expects. + * This function is called when kgdb does not have access to the + * &struct pt_regs and therefore it should fill the gdb registers + * @gdb_regs with what has been saved in &struct thread_struct + * thread field during switch_to. + */ +extern void +sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); + +/* + * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. + * @gdb_regs: A pointer to hold the registers we've received from GDB. + * @regs: A pointer to a &struct pt_regs to hold these values in. + * + * Convert the GDB regs in @gdb_regs into the pt_regs, and store them + * in @regs. + */ +extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); + +/* + * kgdb_arch_handle_exception - Handle architecture specific GDB packets. + * @vector: The error vector of the exception that happened. + * @signo: The signal number of the exception that happened. + * @err_code: The error code of the exception that happened. + * @remcom_in_buffer: The buffer of the packet we have read. + * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. + * @regs: The &struct pt_regs of the current process. + * + * This function MUST handle the 'c' and 's' command packets, + * as well packets to set / remove a hardware breakpoint, if used. + * If there are additional packets which the hardware needs to handle, + * they are handled here. The code should return -1 if it wants to + * process more packets, and a %0 or %1 if it wants to exit from the + * kgdb callback. + */ +extern int +kgdb_arch_handle_exception(int vector, int signo, int err_code, + char *remcom_in_buffer, + char *remcom_out_buffer, + struct pt_regs *regs); + +/* + * kgdb_roundup_cpus - Get other CPUs into a holding pattern + * @flags: Current IRQ state + * + * On SMP systems, we need to get the attention of the other CPUs + * and get them be in a known state. This should do what is needed + * to get the other CPUs to call kgdb_wait(). Note that on some arches, + * the NMI approach is not used for rounding up all the CPUs. For example, + * in case of MIPS, smp_call_function() is used to roundup CPUs. In + * this case, we have to make sure that interrupts are enabled before + * calling smp_call_function(). The argument to this function is + * the flags that will be used when restoring the interrupts. There is + * local_irq_save() call before kgdb_roundup_cpus(). + * + * On non-SMP systems, this is not called. + */ +extern void kgdb_roundup_cpus(unsigned long flags); + +/* 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); + +/* + * struct kgdb_arch - Describe architecture specific values. + * @gdb_bpt_instr: The instruction to trigger a breakpoint. + * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. + * @set_breakpoint: Allow an architecture to specify how to set a software + * breakpoint. + * @remove_breakpoint: Allow an architecture to specify how to remove a + * software breakpoint. + * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware + * breakpoint. + * @remove_hw_breakpoint: Allow an architecture to specify how to remove a + * hardware breakpoint. + * @remove_all_hw_break: Allow an architecture to specify how to remove all + * hardware breakpoints. + * @correct_hw_break: Allow an architecture to specify how to correct the + * hardware debug registers. + */ +struct kgdb_arch { + unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; + unsigned long flags; + + int (*set_breakpoint)(unsigned long, char *); + int (*remove_breakpoint)(unsigned long, char *); + int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); + int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); + void (*remove_all_hw_break)(void); + void (*correct_hw_break)(void); +}; + +/* + * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. + * @name: Name of the I/O driver. + * @read_char: Pointer to a function that will return one char. + * @write_char: Pointer to a function that will write one char. + * @flush: Pointer to a function that will flush any pending writes. + * @init: Pointer to a function that will initialize the device. + * @pre_exception: Pointer to a function that will do any prep work for + * the I/O driver. + * @post_exception: Pointer to a function that will do any cleanup work + * for the I/O driver. + */ +struct kgdb_io { + const char *name; + int (*read_char) (void); + void (*write_char) (u8); + void (*flush) (void); + int (*init) (void); + void (*pre_exception) (void); + void (*post_exception) (void); +}; + +extern struct kgdb_arch arch_kgdb_ops; + +extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); +extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); + +extern int kgdb_hex2long(char **ptr, long *long_val); +extern int kgdb_mem2hex(char *mem, char *buf, int count); +extern int kgdb_hex2mem(char *buf, char *mem, int count); + +extern int kgdb_isremovedbreak(unsigned long addr); + +extern int +kgdb_handle_exception(int ex_vector, int signo, int err_code, + struct pt_regs *regs); +extern int kgdb_nmicallback(int cpu, void *regs); + +extern int kgdb_single_step; +extern atomic_t kgdb_active; + +#endif /* _KGDB_H_ */ diff --git a/include/linux/pid.h b/include/linux/pid.h index f84d532..e066d3d 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -86,6 +86,8 @@ extern struct task_struct *FASTCALL(get_pid_task(struct pid *pid, extern struct pid *get_task_pid(struct task_struct *task, enum pid_type type); +extern int pid_max; + /* * attach_pid() and detach_pid() must be called with the tasklist_lock * write-held. diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 1a0b6cf..7d1a46b 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -211,6 +211,10 @@ struct uart_ops { void (*config_port)(struct uart_port *, int); int (*verify_port)(struct uart_port *, struct serial_struct *); int (*ioctl)(struct uart_port *, unsigned int, unsigned long); +#ifdef CONFIG_CONSOLE_POLL + void (*poll_put_char)(struct uart_port *, unsigned char); + int (*poll_get_char)(struct uart_port *); +#endif }; #define UART_CONFIG_TYPE (1 << 0) diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 85c95cd..21f69ac 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -125,6 +125,7 @@ #include <linux/cdev.h> struct tty_struct; +struct tty_driver; struct tty_operations { int (*open)(struct tty_struct * tty, struct file * filp); @@ -157,6 +158,11 @@ struct tty_operations { int (*tiocmget)(struct tty_struct *tty, struct file *file); int (*tiocmset)(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear); +#ifdef CONFIG_CONSOLE_POLL + int (*poll_init)(struct tty_driver *driver, int line, char *options); + int (*poll_get_char)(struct tty_driver *driver, int line); + void (*poll_put_char)(struct tty_driver *driver, int line, char ch); +#endif }; struct tty_driver { @@ -220,6 +226,11 @@ struct tty_driver { int (*tiocmget)(struct tty_struct *tty, struct file *file); int (*tiocmset)(struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear); +#ifdef CONFIG_CONSOLE_POLL + int (*poll_init)(struct tty_driver *driver, int line, char *options); + int (*poll_get_char)(struct tty_driver *driver, int line); + void (*poll_put_char)(struct tty_driver *driver, int line, char ch); +#endif struct list_head tty_drivers; }; @@ -230,6 +241,7 @@ struct tty_driver *alloc_tty_driver(int lines); void put_tty_driver(struct tty_driver *driver); void tty_set_operations(struct tty_driver *driver, const struct tty_operations *op); +extern struct tty_driver *tty_find_polling_driver(char *name, int *line); /* tty driver magic number */ #define TTY_DRIVER_MAGIC 0x5402 diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 975c963..fec6dec 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -84,4 +84,26 @@ static inline unsigned long __copy_from_user_nocache(void *to, ret; \ }) +/* + * probe_kernel_read(): safely attempt to read from a location + * @dst: pointer to the buffer that shall take the data + * @src: address to read from + * @size: size of the data chunk + * + * Safely read from address @src to the buffer at @dst. If a kernel fault + * happens, handle that and return -EFAULT. + */ +extern long probe_kernel_read(void *dst, void *src, size_t size); + +/* + * probe_kernel_write(): safely attempt to write to a location + * @dst: address to write to + * @src: pointer to the data that shall be written + * @size: size of the data chunk + * + * Safely write to address @dst from the buffer at @src. If a kernel fault + * happens, handle that and return -EFAULT. + */ +extern long probe_kernel_write(void *dst, void *src, size_t size); + #endif /* __LINUX_UACCESS_H__ */ diff --git a/kernel/Makefile b/kernel/Makefile index 6c584c5..05c8003 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_AUDIT_TREE) += audit_tree.o obj-$(CONFIG_KPROBES) += kprobes.o +obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ obj-$(CONFIG_SECCOMP) += seccomp.o diff --git a/kernel/kgdb.c b/kernel/kgdb.c new file mode 100644 index 0000000..2bfdd48 --- /dev/null +++ b/kernel/kgdb.c @@ -0,0 +1,1663 @@ +/* + * KGDB stub. + * + * Maintainer: Jason Wessel <jason.wessel@windriver.com> + * + * Copyright (C) 2000-2001 VERITAS Software Corporation. + * Copyright (C) 2002-2004 Timesys Corporation + * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> + * Copyright (C) 2004 Pavel Machek <pavel@suse.cz> + * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> + * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. + * Copyright (C) 2005-2008 Wind River Systems, Inc. + * Copyright (C) 2007 MontaVista Software, Inc. + * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> + * + * Contributors at various stages not listed above: + * Jason Wessel ( jason.wessel@windriver.com ) + * George Anzinger <george@mvista.com> + * Anurekh Saxena (anurekh.saxena@timesys.com) + * Lake Stevens Instrument Division (Glenn Engel) + * Jim Kingdon, Cygnus Support. + * + * Original KGDB stub: David Grothe <dave@gcom.com>, + * Tigran Aivazian <tigran@sco.com> + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#include <linux/pid_namespace.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/console.h> +#include <linux/threads.h> +#include <linux/uaccess.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/ptrace.h> +#include <linux/reboot.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/sysrq.h> +#include <linux/init.h> +#include <linux/kgdb.h> +#include <linux/pid.h> +#include <linux/smp.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> +#include <asm/byteorder.h> +#include <asm/atomic.h> +#include <asm/system.h> + +static int kgdb_break_asap; + +struct kgdb_state { + int ex_vector; + int signo; + int err_code; + int cpu; + int pass_exception; + long threadid; + long kgdb_usethreadid; + struct pt_regs *linux_regs; +}; + +static struct debuggerinfo_struct { + void *debuggerinfo; + struct task_struct *task; +} kgdb_info[NR_CPUS]; + +/** + * kgdb_connected - Is a host GDB connected to us? + */ +int kgdb_connected; +EXPORT_SYMBOL_GPL(kgdb_connected); + +/* All the KGDB handlers are installed */ +static int kgdb_io_module_registered; + +/* Guard for recursive entry */ +static int exception_level; + +static struct kgdb_io *kgdb_io_ops; +static DEFINE_SPINLOCK(kgdb_registration_lock); + +/* kgdb console driver is loaded */ +static int kgdb_con_registered; +/* determine if kgdb console output should be used */ +static int kgdb_use_con; + +static int __init opt_kgdb_con(char *str) +{ + kgdb_use_con = 1; + return 0; +} + +early_param("kgdbcon", opt_kgdb_con); + +module_param(kgdb_use_con, int, 0644); + +/* + * Holds information about breakpoints in a kernel. These breakpoints are + * added and removed by gdb. + */ +static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { + [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } +}; + +/* + * The CPU# of the active CPU, or -1 if none: + */ +atomic_t kgdb_active = ATOMIC_INIT(-1); + +/* + * We use NR_CPUs not PERCPU, in case kgdb is used to debug early + * bootup code (which might not have percpu set up yet): + */ +static atomic_t passive_cpu_wait[NR_CPUS]; +static atomic_t cpu_in_kgdb[NR_CPUS]; +atomic_t kgdb_setting_breakpoint; + +struct task_struct *kgdb_usethread; +struct task_struct *kgdb_contthread; + +int kgdb_single_step; + +/* Our I/O buffers. */ +static char remcom_in_buffer[BUFMAX]; +static char remcom_out_buffer[BUFMAX]; + +/* Storage for the registers, in GDB format. */ +static unsigned long gdb_regs[(NUMREGBYTES + + sizeof(unsigned long) - 1) / + sizeof(unsigned long)]; + +/* to keep track of the CPU which is doing the single stepping*/ +atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); + +/* + * Finally, some KGDB code :-) + */ + +/* + * Weak aliases for breakpoint management, + * can be overriden by architectures when needed: + */ +int __weak kgdb_validate_break_address(unsigned long addr) +{ + char tmp_variable[BREAK_INSTR_SIZE]; + + return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE); +} + +int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) +{ + int err; + + err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); + if (err) + return err; + + return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, + BREAK_INSTR_SIZE); +} + +int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) +{ + return probe_kernel_write((char *)addr, + (char *)bundle, BREAK_INSTR_SIZE); +} + +unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int __weak kgdb_arch_init(void) +{ + return 0; +} + +/* + * GDB remote protocol parser: + */ + +static const char hexchars[] = "0123456789abcdef"; + +static int hex(char ch) +{ + if ((ch >= 'a') && (ch <= 'f')) + return ch - 'a' + 10; + if ((ch >= '0') && (ch <= '9')) + return ch - '0'; + if ((ch >= 'A') && (ch <= 'F')) + return ch - 'A' + 10; + return -1; +} + +/* scan for the sequence $<data>#<checksum> */ +static void get_packet(char *buffer) +{ + unsigned char checksum; + unsigned char xmitcsum; + int count; + char ch; + + do { + /* + * Spin and wait around for the start character, ignore all + * other characters: + */ + while ((ch = (kgdb_io_ops->read_char())) != '$') + /* nothing */; + + kgdb_connected = 1; + checksum = 0; + xmitcsum = -1; + + count = 0; + + /* + * now, read until a # or end of buffer is found: + */ + while (count < (BUFMAX - 1)) { + ch = kgdb_io_ops->read_char(); + if (ch == '#') + break; + checksum = checksum + ch; + buffer[count] = ch; + count = count + 1; + } + buffer[count] = 0; + + if (ch == '#') { + xmitcsum = hex(kgdb_io_ops->read_char()) << 4; + xmitcsum += hex(kgdb_io_ops->read_char()); + + if (checksum != xmitcsum) + /* failed checksum */ + kgdb_io_ops->write_char('-'); + else + /* successful transfer */ + kgdb_io_ops->write_char('+'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + } + } while (checksum != xmitcsum); +} + +/* + * Send the packet in buffer. + * Check for gdb connection if asked for. + */ +static void put_packet(char *buffer) +{ + unsigned char checksum; + int count; + char ch; + + /* + * $<packet info>#<checksum>. + */ + while (1) { + kgdb_io_ops->write_char('$'); + checksum = 0; + count = 0; + + while ((ch = buffer[count])) { + kgdb_io_ops->write_char(ch); + checksum += ch; + count++; + } + + kgdb_io_ops->write_char('#'); + kgdb_io_ops->write_char(hexchars[checksum >> 4]); + kgdb_io_ops->write_char(hexchars[checksum & 0xf]); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + + /* Now see what we get in reply. */ + ch = kgdb_io_ops->read_char(); + + if (ch == 3) + ch = kgdb_io_ops->read_char(); + + /* If we get an ACK, we are done. */ + if (ch == '+') + return; + + /* + * If we get the start of another packet, this means + * that GDB is attempting to reconnect. We will NAK + * the packet being sent, and stop trying to send this + * packet. + */ + if (ch == '$') { + kgdb_io_ops->write_char('-'); + if (kgdb_io_ops->flush) + kgdb_io_ops->flush(); + return; + } + } +} + +static char *pack_hex_byte(char *pkt, u8 byte) +{ + *pkt++ = hexchars[byte >> 4]; + *pkt++ = hexchars[byte & 0xf]; + + return pkt; +} + +/* + * Convert the memory pointed to by mem into hex, placing result in buf. + * Return a pointer to the last char put in buf (null). May return an error. + */ +int kgdb_mem2hex(char *mem, char *buf, int count) +{ + char *tmp; + int err; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory copy. Hex conversion will work against this one. + */ + tmp = buf + count; + + err = probe_kernel_read(tmp, mem, count); + if (!err) { + while (count > 0) { + buf = pack_hex_byte(buf, *tmp); + tmp++; + count--; + } + + *buf = 0; + } + + return err; +} + +/* + * Copy the binary array pointed to by buf into mem. Fix $, #, and + * 0x7d escaped with 0x7d. Return a pointer to the character after + * the last byte written. + */ +static int kgdb_ebin2mem(char *buf, char *mem, int count) +{ + int err = 0; + char c; + + while (count-- > 0) { + c = *buf++; + if (c == 0x7d) + c = *buf++ ^ 0x20; + + err = probe_kernel_write(mem, &c, 1); + if (err) + break; + + mem++; + } + + return err; +} + +/* + * Convert the hex array pointed to by buf into binary to be placed in mem. + * Return a pointer to the character AFTER the last byte written. + * May return an error. + */ +int kgdb_hex2mem(char *buf, char *mem, int count) +{ + char *tmp_raw; + char *tmp_hex; + + /* + * We use the upper half of buf as an intermediate buffer for the + * raw memory that is converted from hex. + */ + tmp_raw = buf + count * 2; + + tmp_hex = tmp_raw - 1; + while (tmp_hex >= buf) { + tmp_raw--; + *tmp_raw = hex(*tmp_hex--); + *tmp_raw |= hex(*tmp_hex--) << 4; + } + + return probe_kernel_write(mem, tmp_raw, count); +} + +/* + * While we find nice hex chars, build a long_val. + * Return number of chars processed. + */ +int kgdb_hex2long(char **ptr, long *long_val) +{ + int hex_val; + int num = 0; + + *long_val = 0; + + while (**ptr) { + hex_val = hex(**ptr); + if (hex_val < 0) + break; + + *long_val = (*long_val << 4) | hex_val; + num++; + (*ptr)++; + } + + return num; +} + +/* Write memory due to an 'M' or 'X' packet. */ +static int write_mem_msg(int binary) +{ + char *ptr = &remcom_in_buffer[1]; + unsigned long addr; + unsigned long length; + int err; + + if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && + kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { + if (binary) + err = kgdb_ebin2mem(ptr, (char *)addr, length); + else + err = kgdb_hex2mem(ptr, (char *)addr, length); + if (err) + return err; + if (CACHE_FLUSH_IS_SAFE) + flush_icache_range(addr, addr + length + 1); + return 0; + } + + return -EINVAL; +} + +static void error_packet(char *pkt, int error) +{ + error = -error; + pkt[0] = 'E'; + pkt[1] = hexchars[(error / 10)]; + pkt[2] = hexchars[(error % 10)]; + pkt[3] = '\0'; +} + +/* + * Black magic portion #2. Thread ID accessors. + */ + +#define BUF_THREAD_ID_SIZE 16 + +static char *pack_threadid(char *pkt, unsigned char *id) +{ + char *limit; + + limit = pkt + BUF_THREAD_ID_SIZE; + while (pkt < limit) + pkt = pack_hex_byte(pkt, *id++); + + return pkt; +} + +static void int_to_threadref(unsigned char *id, int value) +{ + unsigned char *scan; + int i = 4; + + scan = (unsigned char *)id; + while (i--) + *scan++ = 0; + *scan++ = (value >> 24) & 0xff; + *scan++ = (value >> 16) & 0xff; + *scan++ = (value >> 8) & 0xff; + *scan++ = (value & 0xff); +} + +static struct task_struct *getthread(struct pt_regs *regs, int tid) +{ + if (num_online_cpus() && (tid >= pid_max + num_online_cpus())) + return NULL; + + if (tid >= pid_max) + return idle_task(tid - pid_max); + + if (!tid) + return NULL; + + /* + * find_task_by_pid() does not take the tasklist lock anymore + * but is nicely RCU locked - hence is a pretty resilient + * thing to use: + */ + return find_task_by_pid(tid); +} + +/* + * CPU debug state control: + */ + +#ifdef CONFIG_SMP +static void kgdb_wait(struct pt_regs *regs) +{ + unsigned long flags; + int cpu; + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + kgdb_info[cpu].debuggerinfo = regs; + kgdb_info[cpu].task = current; + /* + * Make sure the above info reaches the primary CPU before + * our cpu_in_kgdb[] flag setting does: + */ + smp_wmb(); + atomic_set(&cpu_in_kgdb[cpu], 1); + + /* + * The primary CPU must be active to enter here, but this is + * guard in case the primary CPU had not been selected if + * this was an entry via nmi. + */ + while (atomic_read(&kgdb_active) == -1) + cpu_relax(); + + /* Wait till primary CPU goes completely into the debugger. */ + while (!atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) + cpu_relax(); + + /* Wait till primary CPU is done with debugging */ + while (atomic_read(&passive_cpu_wait[cpu])) + cpu_relax(); + + kgdb_info[cpu].debuggerinfo = NULL; + kgdb_info[cpu].task = NULL; + + /* fix up hardware debug registers on local cpu */ + if (arch_kgdb_ops.correct_hw_break) + arch_kgdb_ops.correct_hw_break(); + + /* Signal the primary CPU that we are done: */ + atomic_set(&cpu_in_kgdb[cpu], 0); + local_irq_restore(flags); +} +#endif + +/* + * Some architectures need cache flushes when we set/clear a + * breakpoint: + */ +static void kgdb_flush_swbreak_addr(unsigned long addr) +{ + if (!CACHE_FLUSH_IS_SAFE) + return; + + if (current->mm) { + flush_cache_range(current->mm->mmap_cache, + addr, addr + BREAK_INSTR_SIZE); + } else { + flush_icache_range(addr, addr + BREAK_INSTR_SIZE); + } +} + +/* + * SW breakpoint management: + */ +static int kgdb_activate_sw_breakpoints(void) +{ + unsigned long addr; + int error = 0; + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + 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); + if (error) + return error; + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_ACTIVE; + } + return 0; +} + +static int kgdb_set_sw_break(unsigned long addr) +{ + int err = kgdb_validate_break_address(addr); + int breakno = -1; + int i; + + if (err) + return err; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) + return -EEXIST; + } + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_REMOVED && + kgdb_break[i].bpt_addr == addr) { + breakno = i; + break; + } + } + + if (breakno == -1) { + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state == BP_UNDEFINED) { + breakno = i; + break; + } + } + } + + if (breakno == -1) + return -E2BIG; + + kgdb_break[breakno].state = BP_SET; + kgdb_break[breakno].type = BP_BREAKPOINT; + kgdb_break[breakno].bpt_addr = addr; + + return 0; +} + +static int kgdb_deactivate_sw_breakpoints(void) +{ + unsigned long addr; + int error = 0; + int i; + + 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); + if (error) + return error; + + kgdb_flush_swbreak_addr(addr); + kgdb_break[i].state = BP_SET; + } + return 0; +} + +static int kgdb_remove_sw_break(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_SET) && + (kgdb_break[i].bpt_addr == addr)) { + kgdb_break[i].state = BP_REMOVED; + return 0; + } + } + return -ENOENT; +} + +int kgdb_isremovedbreak(unsigned long addr) +{ + int i; + + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if ((kgdb_break[i].state == BP_REMOVED) && + (kgdb_break[i].bpt_addr == addr)) + return 1; + } + return 0; +} + +int remove_all_break(void) +{ + unsigned long addr; + int error; + int i; + + /* Clear memory breakpoints. */ + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (kgdb_break[i].state != BP_SET) + continue; + addr = kgdb_break[i].bpt_addr; + error = kgdb_arch_remove_breakpoint(addr, + kgdb_break[i].saved_instr); + if
