MIPS: traps: return correct si code for accessing nonmapped addresses

find_vma() returns the first VMA which satisfies fault_addr < vm_end, but
it does not guarantee fault_addr is actually within VMA. Therefore, kernel
has to check that before it chooses correct si code on return.

Signed-off-by: Petar Jovanovic <petar.jovanovic@rt-rk.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13808/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Petar Jovanovic 2016-07-13 15:23:37 +02:00 committed by Ralf Baechle
parent 008d0cf1ec
commit bcfc8f0d4a

View File

@ -704,6 +704,7 @@ asmlinkage void do_ov(struct pt_regs *regs)
int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
{
struct siginfo si = { 0 };
struct vm_area_struct *vma;
switch (sig) {
case 0:
@ -744,7 +745,8 @@ int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
si.si_addr = fault_addr;
si.si_signo = sig;
down_read(&current->mm->mmap_sem);
if (find_vma(current->mm, (unsigned long)fault_addr))
vma = find_vma(current->mm, (unsigned long)fault_addr);
if (vma && (vma->vm_start <= (unsigned long)fault_addr))
si.si_code = SEGV_ACCERR;
else
si.si_code = SEGV_MAPERR;