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

Commit 5fae3d7b authored by Hanumant Singh's avatar Hanumant Singh Committed by Matt Wagantall
Browse files

arm: Dump only kernel region and avoid dumping in user mode 



Dump of memory surrounding register values can leak
kernel information in case of a user level fault.
Also virt_addr_valid() confirms whether a given virtual
address linearly maps to a kernel physical address.
Thus it offers a more exhaustive test for valid kernel
space then a check for is_vmalloc().

Change-Id: Ie394ec26e5ff7fd7bed1e7308a55b0033eddfe7c
Signed-off-by: default avatarHanumant Singh <hanumant@codeaurora.org>
[joshc: adapted to apply to android-3.14, which meant adding
virt_addr_valid() in condition instead of replacing is_vmalloc()]
Signed-off-by: default avatarJosh Cartwright <joshc@codeaurora.org>
parent 88553a7f

arch/arm/kernel/process.c

+4 −8
Original line number Diff line number Diff line
@@ -330,7 +330,8 @@ static void show_data(unsigned long addr, int nbytes, const char *name) 
		printk("%04lx ", (unsigned long)p & 0xffff);

		for (j = 0; j < 8; j++) {

			u32	data;

			if (probe_kernel_address(p, data)) {

			if (!virt_addr_valid(p) ||

			    probe_kernel_address(p, data)) {

				printk(" ********");

			} else {

				printk(" %08x", data);
@@ -343,10 +344,6 @@ static void show_data(unsigned long addr, int nbytes, const char *name) 


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");
@@ -363,7 +360,6 @@ static void show_extra_register_data(struct pt_regs *regs, int nbytes) 
	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)
@@ -427,7 +423,7 @@ void __show_regs(struct pt_regs *regs) 
		printk("Control: %08x%s\n", ctrl, buf);

	}

#endif



	if (get_fs() == get_ds())

		show_extra_register_data(regs, 128);

}