redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

sparc32: Fix unaligned stack handling on trap return.

Browse source 
When the rett stack checking code sees the stack is unaligned (in both
the sun4c and srmmu cases) it jumps to the window fault-in path.

But that just tries to page the stack pages in, it doesn't do anything
special if the stack is misaligned.

Therefore we essentially just loop forever in the trap return path.

Fix this by emitting a SIGILL in the stack fault-in code if the stack
is mis-aligned.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2010-09-23 22:06:47 -07:00
parent caebf9103b
commit 9088333e3d
1 changed files with 12 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
arch/sparc/mm/fault_32.c
View file

@ -539,6 +539,12 @@ do_sigbus:
__do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
}
static void check_stack_aligned(unsigned long sp)
{
if (sp & 0x7UL)
force_sig(SIGILL, current);
}
void window_overflow_fault(void)
{
unsigned long sp;
@ -547,6 +553,8 @@ void window_overflow_fault(void)
if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
force_user_fault(sp + 0x38, 1);
force_user_fault(sp, 1);
check_stack_aligned(sp);
}
void window_underflow_fault(unsigned long sp)
@ -554,6 +562,8 @@ void window_underflow_fault(unsigned long sp)
if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
force_user_fault(sp + 0x38, 0);
force_user_fault(sp, 0);
check_stack_aligned(sp);
}
void window_ret_fault(struct pt_regs *regs)
@ -564,4 +574,6 @@ void window_ret_fault(struct pt_regs *regs)
if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
force_user_fault(sp + 0x38, 0);
force_user_fault(sp, 0);
check_stack_aligned(sp);
}