diff options
Diffstat (limited to 'drivers/staging/android/fiq_debugger/fiq_debugger_arm.c')
-rw-r--r-- | drivers/staging/android/fiq_debugger/fiq_debugger_arm.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c b/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c new file mode 100644 index 000000000000..8b3e0137be1a --- /dev/null +++ b/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c @@ -0,0 +1,240 @@ +/* + * Copyright (C) 2014 Google, Inc. + * Author: Colin Cross <ccross@android.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + * + */ + +#include <linux/ptrace.h> +#include <linux/uaccess.h> + +#include <asm/stacktrace.h> + +#include "fiq_debugger_priv.h" + +static char *mode_name(unsigned cpsr) +{ + switch (cpsr & MODE_MASK) { + case USR_MODE: return "USR"; + case FIQ_MODE: return "FIQ"; + case IRQ_MODE: return "IRQ"; + case SVC_MODE: return "SVC"; + case ABT_MODE: return "ABT"; + case UND_MODE: return "UND"; + case SYSTEM_MODE: return "SYS"; + default: return "???"; + } +} + +void fiq_debugger_dump_pc(struct fiq_debugger_output *output, + const struct pt_regs *regs) +{ + output->printf(output, " pc %08x cpsr %08x mode %s\n", + regs->ARM_pc, regs->ARM_cpsr, mode_name(regs->ARM_cpsr)); +} + +void fiq_debugger_dump_regs(struct fiq_debugger_output *output, + const struct pt_regs *regs) +{ + output->printf(output, + " r0 %08x r1 %08x r2 %08x r3 %08x\n", + regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3); + output->printf(output, + " r4 %08x r5 %08x r6 %08x r7 %08x\n", + regs->ARM_r4, regs->ARM_r5, regs->ARM_r6, regs->ARM_r7); + output->printf(output, + " r8 %08x r9 %08x r10 %08x r11 %08x mode %s\n", + regs->ARM_r8, regs->ARM_r9, regs->ARM_r10, regs->ARM_fp, + mode_name(regs->ARM_cpsr)); + output->printf(output, + " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n", + regs->ARM_ip, regs->ARM_sp, regs->ARM_lr, regs->ARM_pc, + regs->ARM_cpsr); +} + +struct mode_regs { + unsigned long sp_svc; + unsigned long lr_svc; + unsigned long spsr_svc; + + unsigned long sp_abt; + unsigned long lr_abt; + unsigned long spsr_abt; + + unsigned long sp_und; + unsigned long lr_und; + unsigned long spsr_und; + + unsigned long sp_irq; + unsigned long lr_irq; + unsigned long spsr_irq; + + unsigned long r8_fiq; + unsigned long r9_fiq; + unsigned long r10_fiq; + unsigned long r11_fiq; + unsigned long r12_fiq; + unsigned long sp_fiq; + unsigned long lr_fiq; + unsigned long spsr_fiq; +}; + +static void __naked get_mode_regs(struct mode_regs *regs) +{ + asm volatile ( + "mrs r1, cpsr\n" + "msr cpsr_c, #0xd3 @(SVC_MODE | PSR_I_BIT | PSR_F_BIT)\n" + "stmia r0!, {r13 - r14}\n" + "mrs r2, spsr\n" + "msr cpsr_c, #0xd7 @(ABT_MODE | PSR_I_BIT | PSR_F_BIT)\n" + "stmia r0!, {r2, r13 - r14}\n" + "mrs r2, spsr\n" + "msr cpsr_c, #0xdb @(UND_MODE | PSR_I_BIT | PSR_F_BIT)\n" + "stmia r0!, {r2, r13 - r14}\n" + "mrs r2, spsr\n" + "msr cpsr_c, #0xd2 @(IRQ_MODE | PSR_I_BIT | PSR_F_BIT)\n" + "stmia r0!, {r2, r13 - r14}\n" + "mrs r2, spsr\n" + "msr cpsr_c, #0xd1 @(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)\n" + "stmia r0!, {r2, r8 - r14}\n" + "mrs r2, spsr\n" + "stmia r0!, {r2}\n" + "msr cpsr_c, r1\n" + "bx lr\n"); +} + + +void fiq_debugger_dump_allregs(struct fiq_debugger_output *output, + const struct pt_regs *regs) +{ + struct mode_regs mode_regs; + unsigned long mode = regs->ARM_cpsr & MODE_MASK; + + fiq_debugger_dump_regs(output, regs); + get_mode_regs(&mode_regs); + + output->printf(output, + "%csvc: sp %08x lr %08x spsr %08x\n", + mode == SVC_MODE ? '*' : ' ', + mode_regs.sp_svc, mode_regs.lr_svc, mode_regs.spsr_svc); + output->printf(output, + "%cabt: sp %08x lr %08x spsr %08x\n", + mode == ABT_MODE ? '*' : ' ', + mode_regs.sp_abt, mode_regs.lr_abt, mode_regs.spsr_abt); + output->printf(output, + "%cund: sp %08x lr %08x spsr %08x\n", + mode == UND_MODE ? '*' : ' ', + mode_regs.sp_und, mode_regs.lr_und, mode_regs.spsr_und); + output->printf(output, + "%cirq: sp %08x lr %08x spsr %08x\n", + mode == IRQ_MODE ? '*' : ' ', + mode_regs.sp_irq, mode_regs.lr_irq, mode_regs.spsr_irq); + output->printf(output, + "%cfiq: r8 %08x r9 %08x r10 %08x r11 %08x r12 %08x\n", + mode == FIQ_MODE ? '*' : ' ', + mode_regs.r8_fiq, mode_regs.r9_fiq, mode_regs.r10_fiq, + mode_regs.r11_fiq, mode_regs.r12_fiq); + output->printf(output, + " fiq: sp %08x lr %08x spsr %08x\n", + mode_regs.sp_fiq, mode_regs.lr_fiq, mode_regs.spsr_fiq); +} + +struct stacktrace_state { + struct fiq_debugger_output *output; + unsigned int depth; +}; + +static int report_trace(struct stackframe *frame, void *d) +{ + struct stacktrace_state *sts = d; + + if (sts->depth) { + sts->output->printf(sts->output, + " pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n", + frame->pc, frame->pc, frame->lr, frame->lr, + frame->sp, frame->fp); + sts->depth--; + return 0; + } + sts->output->printf(sts->output, " ...\n"); + + return sts->depth == 0; +} + +struct frame_tail { + struct frame_tail *fp; + unsigned long sp; + unsigned long lr; +} __attribute__((packed)); + +static struct frame_tail *user_backtrace(struct fiq_debugger_output *output, + struct frame_tail *tail) +{ + struct frame_tail buftail[2]; + + /* Also check accessibility of one struct frame_tail beyond */ + if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) { + output->printf(output, " invalid frame pointer %p\n", + tail); + return NULL; + } + if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail))) { + output->printf(output, + " failed to copy frame pointer %p\n", tail); + return NULL; + } + + output->printf(output, " %p\n", buftail[0].lr); + + /* frame pointers should strictly progress back up the stack + * (towards higher addresses) */ + if (tail >= buftail[0].fp) + return NULL; + + return buftail[0].fp-1; +} + +void fiq_debugger_dump_stacktrace(struct fiq_debugger_output *output, + const struct pt_regs *regs, unsigned int depth, void *ssp) +{ + struct frame_tail *tail; + struct thread_info *real_thread_info = THREAD_INFO(ssp); + struct stacktrace_state sts; + + sts.depth = depth; + sts.output = output; + *current_thread_info() = *real_thread_info; + + if (!current) + output->printf(output, "current NULL\n"); + else + output->printf(output, "pid: %d comm: %s\n", + current->pid, current->comm); + fiq_debugger_dump_regs(output, regs); + + if (!user_mode(regs)) { + struct stackframe frame; + frame.fp = regs->ARM_fp; + frame.sp = regs->ARM_sp; + frame.lr = regs->ARM_lr; + frame.pc = regs->ARM_pc; + output->printf(output, + " pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n", + regs->ARM_pc, regs->ARM_pc, regs->ARM_lr, regs->ARM_lr, + regs->ARM_sp, regs->ARM_fp); + walk_stackframe(&frame, report_trace, &sts); + return; + } + + tail = ((struct frame_tail *) regs->ARM_fp) - 1; + while (depth-- && tail && !((unsigned long) tail & 3)) + tail = user_backtrace(output, tail); +} |