Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c6023aa6 authored by San Mehat's avatar San Mehat Committed by Dmitry Shmidt
Browse files

ANDROID: process: Add display of memory around registers when displaying regs. 



This is extremely useful in diagnosing remote crashes, and is based heavily
on original work by <md@google.com>.

Signed-off-by: default avatarSan Mehat <san@google.com>
Cc: Michael Davidson <md@google.com>

[ARM] process: Use uber-safe probe_kernel_address() to read mem when dumping.

This prevents the dump from taking pagefaults / external aborts.

Change-Id: I8df76e8638780f94fb1bd7ea4471e3f7b01df950
Signed-off-by: default avatarSan Mehat <san@google.com>
parent 122dd3c6

arch/arm/kernel/process.c

+73 −0
Original line number Diff line number Diff line
@@ -93,6 +93,77 @@ void arch_cpu_idle_exit(void) 
	idle_notifier_call_chain(IDLE_END);

}



/*

 * 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;



	fs = get_fs();

	set_fs(KERNEL_DS);

	show_data(regs->ARM_pc - nbytes, nbytes * 2, "PC");

	show_data(regs->ARM_lr - nbytes, nbytes * 2, "LR");

	show_data(regs->ARM_sp - nbytes, nbytes * 2, "SP");

	show_data(regs->ARM_ip - nbytes, nbytes * 2, "IP");

	show_data(regs->ARM_fp - nbytes, nbytes * 2, "FP");

	show_data(regs->ARM_r0 - nbytes, nbytes * 2, "R0");

	show_data(regs->ARM_r1 - nbytes, nbytes * 2, "R1");

	show_data(regs->ARM_r2 - nbytes, nbytes * 2, "R2");

	show_data(regs->ARM_r3 - nbytes, nbytes * 2, "R3");

	show_data(regs->ARM_r4 - nbytes, nbytes * 2, "R4");

	show_data(regs->ARM_r5 - nbytes, nbytes * 2, "R5");

	show_data(regs->ARM_r6 - nbytes, nbytes * 2, "R6");

	show_data(regs->ARM_r7 - nbytes, nbytes * 2, "R7");

	show_data(regs->ARM_r8 - nbytes, nbytes * 2, "R8");

	show_data(regs->ARM_r9 - nbytes, nbytes * 2, "R9");

	show_data(regs->ARM_r10 - nbytes, nbytes * 2, "R10");

	set_fs(fs);

}



void __show_regs(struct pt_regs *regs)

{

	unsigned long flags;
@@ -184,6 +255,8 @@ void __show_regs(struct pt_regs *regs) 
		printk("Control: %08x%s\n", ctrl, buf);

	}

#endif



	show_extra_register_data(regs, 128);

}



void show_regs(struct pt_regs * regs)