From 081513b5f5f79f759beb2a542d89ca61c0967ac8 Mon Sep 17 00:00:00 2001 From: Greg Hackmann Date: Tue, 9 Sep 2014 17:36:05 -0700 Subject: [PATCH] ANDROID: arm64: process: dump memory around registers when displaying regs A port of 8608d7c4418c75841c562a90cddd9beae5798a48 to ARM64. Both the original code and this port are limited to dumping kernel addresses, so don't bother if the registers are from a userspace process. Change-Id: Idc76804c54efaaeb70311cbb500c54db6dac4525 Signed-off-by: Greg Hackmann --- arch/arm64/kernel/process.c | 67 +++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 2dc0f8482210..8435d973984e 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -170,6 +170,70 @@ void machine_restart(char *cmd) while (1); } +/* + * dump a block of kernel memory from around the given address + */ +static void show_data(unsigned long addr, int nbytes, const char *name) +{ + int i, j; + int nlines; + u32 *p; + + /* + * don't attempt to dump non-kernel addresses or + * values that are probably just small negative numbers + */ + if (addr < PAGE_OFFSET || addr > -256UL) + return; + + printk("\n%s: %#lx:\n", name, addr); + + /* + * round address down to a 32 bit boundary + * and always dump a multiple of 32 bytes + */ + p = (u32 *)(addr & ~(sizeof(u32) - 1)); + nbytes += (addr & (sizeof(u32) - 1)); + nlines = (nbytes + 31) / 32; + + + for (i = 0; i < nlines; i++) { + /* + * just display low 16 bits of address to keep + * each line of the dump < 80 characters + */ + printk("%04lx ", (unsigned long)p & 0xffff); + for (j = 0; j < 8; j++) { + u32 data; + if (probe_kernel_address(p, data)) { + printk(" ********"); + } else { + printk(" %08x", data); + } + ++p; + } + printk("\n"); + } +} + +static void show_extra_register_data(struct pt_regs *regs, int nbytes) +{ + mm_segment_t fs; + unsigned int i; + + fs = get_fs(); + set_fs(KERNEL_DS); + show_data(regs->pc - nbytes, nbytes * 2, "PC"); + show_data(regs->regs[30] - nbytes, nbytes * 2, "LR"); + show_data(regs->sp - nbytes, nbytes * 2, "SP"); + for (i = 0; i < 30; i++) { + char name[4]; + snprintf(name, sizeof(name), "X%u", i); + show_data(regs->regs[i] - nbytes, nbytes * 2, name); + } + set_fs(fs); +} + void __show_regs(struct pt_regs *regs) { int i, top_reg; @@ -205,6 +269,9 @@ void __show_regs(struct pt_regs *regs) pr_cont("\n"); } + if (!user_mode(regs)) + show_extra_register_data(regs, 128); + printk("\n"); } void show_regs(struct pt_regs * regs) -- 2.20.1