diff options
author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2006-09-25 23:32:13 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:54 -0700 |
commit | 5f97f7f9400de47ae837170bb274e90ad3934386 (patch) | |
tree | 514451e6dc6b46253293a00035d375e77b1c65ed /arch/avr32/kernel/kprobes.c | |
parent | 53e62d3aaa60590d4a69b4e07c29f448b5151047 (diff) | |
download | linux-5f97f7f9400de47ae837170bb274e90ad3934386.tar.bz2 |
[PATCH] avr32 architecture
This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.
AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density. The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.
The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available from
http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf
The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture. It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit. It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.
Full data sheet is available from
http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf
while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available from
http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf
Information about the AT32STK1000 development board can be found at
http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918
including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.
Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.
This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.
[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/avr32/kernel/kprobes.c')
-rw-r--r-- | arch/avr32/kernel/kprobes.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/avr32/kernel/kprobes.c b/arch/avr32/kernel/kprobes.c new file mode 100644 index 000000000000..6caf9e8d8080 --- /dev/null +++ b/arch/avr32/kernel/kprobes.c @@ -0,0 +1,270 @@ +/* + * Kernel Probes (KProbes) + * + * Copyright (C) 2005-2006 Atmel Corporation + * + * Based on arch/ppc64/kernel/kprobes.c + * Copyright (C) IBM Corporation, 2002, 2004 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kprobes.h> +#include <linux/ptrace.h> + +#include <asm/cacheflush.h> +#include <asm/kdebug.h> +#include <asm/ocd.h> + +DEFINE_PER_CPU(struct kprobe *, current_kprobe); +static unsigned long kprobe_status; +static struct pt_regs jprobe_saved_regs; + +int __kprobes arch_prepare_kprobe(struct kprobe *p) +{ + int ret = 0; + + if ((unsigned long)p->addr & 0x01) { + printk("Attempt to register kprobe at an unaligned address\n"); + ret = -EINVAL; + } + + /* XXX: Might be a good idea to check if p->addr is a valid + * kernel address as well... */ + + if (!ret) { + pr_debug("copy kprobe at %p\n", p->addr); + memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + p->opcode = *p->addr; + } + + return ret; +} + +void __kprobes arch_arm_kprobe(struct kprobe *p) +{ + pr_debug("arming kprobe at %p\n", p->addr); + *p->addr = BREAKPOINT_INSTRUCTION; + flush_icache_range((unsigned long)p->addr, + (unsigned long)p->addr + sizeof(kprobe_opcode_t)); +} + +void __kprobes arch_disarm_kprobe(struct kprobe *p) +{ + pr_debug("disarming kprobe at %p\n", p->addr); + *p->addr = p->opcode; + flush_icache_range((unsigned long)p->addr, + (unsigned long)p->addr + sizeof(kprobe_opcode_t)); +} + +static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) +{ + unsigned long dc; + + pr_debug("preparing to singlestep over %p (PC=%08lx)\n", + p->addr, regs->pc); + + BUG_ON(!(sysreg_read(SR) & SYSREG_BIT(SR_D))); + + dc = __mfdr(DBGREG_DC); + dc |= DC_SS; + __mtdr(DBGREG_DC, dc); + + /* + * We must run the instruction from its original location + * since it may actually reference PC. + * + * TODO: Do the instruction replacement directly in icache. + */ + *p->addr = p->opcode; + flush_icache_range((unsigned long)p->addr, + (unsigned long)p->addr + sizeof(kprobe_opcode_t)); +} + +static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) +{ + unsigned long dc; + + pr_debug("resuming execution at PC=%08lx\n", regs->pc); + + dc = __mfdr(DBGREG_DC); + dc &= ~DC_SS; + __mtdr(DBGREG_DC, dc); + + *p->addr = BREAKPOINT_INSTRUCTION; + flush_icache_range((unsigned long)p->addr, + (unsigned long)p->addr + sizeof(kprobe_opcode_t)); +} + +static void __kprobes set_current_kprobe(struct kprobe *p) +{ + __get_cpu_var(current_kprobe) = p; +} + +static int __kprobes kprobe_handler(struct pt_regs *regs) +{ + struct kprobe *p; + void *addr = (void *)regs->pc; + int ret = 0; + + pr_debug("kprobe_handler: kprobe_running=%d\n", + kprobe_running()); + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing + */ + preempt_disable(); + + /* Check that we're not recursing */ + if (kprobe_running()) { + p = get_kprobe(addr); + if (p) { + if (kprobe_status == KPROBE_HIT_SS) { + printk("FIXME: kprobe hit while single-stepping!\n"); + goto no_kprobe; + } + + printk("FIXME: kprobe hit while handling another kprobe\n"); + goto no_kprobe; + } else { + p = kprobe_running(); + if (p->break_handler && p->break_handler(p, regs)) + goto ss_probe; + } + /* If it's not ours, can't be delete race, (we hold lock). */ + goto no_kprobe; + } + + p = get_kprobe(addr); + if (!p) + goto no_kprobe; + + kprobe_status = KPROBE_HIT_ACTIVE; + set_current_kprobe(p); + if (p->pre_handler && p->pre_handler(p, regs)) + /* handler has already set things up, so skip ss setup */ + return 1; + +ss_probe: + prepare_singlestep(p, regs); + kprobe_status = KPROBE_HIT_SS; + return 1; + +no_kprobe: + return ret; +} + +static int __kprobes post_kprobe_handler(struct pt_regs *regs) +{ + struct kprobe *cur = kprobe_running(); + + pr_debug("post_kprobe_handler, cur=%p\n", cur); + + if (!cur) + return 0; + + if (cur->post_handler) { + kprobe_status = KPROBE_HIT_SSDONE; + cur->post_handler(cur, regs, 0); + } + + resume_execution(cur, regs); + reset_current_kprobe(); + preempt_enable_no_resched(); + + return 1; +} + +static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) +{ + struct kprobe *cur = kprobe_running(); + + pr_debug("kprobe_fault_handler: trapnr=%d\n", trapnr); + + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) + return 1; + + if (kprobe_status & KPROBE_HIT_SS) { + resume_execution(cur, regs); + preempt_enable_no_resched(); + } + return 0; +} + +/* + * Wrapper routine to for handling exceptions. + */ +int __kprobes kprobe_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct die_args *args = (struct die_args *)data; + int ret = NOTIFY_DONE; + + pr_debug("kprobe_exceptions_notify: val=%lu, data=%p\n", + val, data); + + switch (val) { + case DIE_BREAKPOINT: + if (kprobe_handler(args->regs)) + ret = NOTIFY_STOP; + break; + case DIE_SSTEP: + if (post_kprobe_handler(args->regs)) + ret = NOTIFY_STOP; + break; + case DIE_FAULT: + if (kprobe_running() + && kprobe_fault_handler(args->regs, args->trapnr)) + ret = NOTIFY_STOP; + break; + default: + break; + } + + return ret; +} + +int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) +{ + struct jprobe *jp = container_of(p, struct jprobe, kp); + + memcpy(&jprobe_saved_regs, regs, sizeof(struct pt_regs)); + + /* + * TODO: We should probably save some of the stack here as + * well, since gcc may pass arguments on the stack for certain + * functions (lots of arguments, large aggregates, varargs) + */ + + /* setup return addr to the jprobe handler routine */ + regs->pc = (unsigned long)jp->entry; + return 1; +} + +void __kprobes jprobe_return(void) +{ + asm volatile("breakpoint" ::: "memory"); +} + +int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) +{ + /* + * FIXME - we should ideally be validating that we got here 'cos + * of the "trap" in jprobe_return() above, before restoring the + * saved regs... + */ + memcpy(regs, &jprobe_saved_regs, sizeof(struct pt_regs)); + return 1; +} + +int __init arch_init_kprobes(void) +{ + printk("KPROBES: Enabling monitor mode (MM|DBE)...\n"); + __mtdr(DBGREG_DC, DC_MM | DC_DBE); + + /* TODO: Register kretprobe trampoline */ + return 0; +} |