unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

[MIPS] Fix check for valid stack pointer during backtrace

Browse source 
The newly added check for valid stack pointer address breaks at least for
64bit kernels.  Use __get_user() for accessing stack content to avoid crashes,
when doing the backtrace.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Thomas Bogendoerfer 2008-05-12 17:58:48 +02:00 committed by Ralf Baechle
parent 057229f9ef
commit 10220c8844
1 changed files with 9 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
arch/mips/kernel/traps.c
View file

@ -88,15 +88,17 @@ static void show_raw_backtrace(unsigned long reg29)
#ifdef CONFIG_KALLSYMS
printk("\n");
#endif
#define IS_KVA01(a) ((((unsigned int)a) & 0xc0000000) == 0x80000000)
if (IS_KVA01(sp)) {
while (!kstack_end(sp)) {
addr = *sp++;
if (__kernel_text_address(addr))
print_ip_sym(addr);
while (!kstack_end(sp)) {
unsigned long __user *p =
(unsigned long __user *)(unsigned long)sp++;
if (__get_user(addr, p)) {
printk(" (Bad stack address)");
break;
}
printk("\n");
if (__kernel_text_address(addr))
print_ip_sym(addr);
}
printk("\n");
}
#ifdef CONFIG_KALLSYMS