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

Commit 2a59e96e authored by Greg Hackmann's avatar Greg Hackmann Committed by Ruchi Kandoi
Browse files

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: default avatarGreg Hackmann <ghackmann@google.com>
parent bd7f8592

arch/arm64/kernel/process.c

+66 −0
Original line number Diff line number Diff line
@@ -163,6 +163,70 @@ 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;
@@ -189,6 +253,8 @@ void __show_regs(struct pt_regs *regs) 
		if (i % 2 == 0)

			printk("\n");

	}

	if (!user_mode(regs))

		show_extra_register_data(regs, 128);

	printk("\n");

}