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authorDavid S. Miller <davem@davemloft.net>2010-09-23 22:06:47 -0700
committerDavid S. Miller <davem@davemloft.net>2010-10-26 08:59:55 -0700
commit9088333e3d83a68aeac15f7810c3cbf332b80303 (patch)
tree7187e09ba5e21ee60df9c1efc6d2b8f793e64399 /arch/sparc
parentcaebf9103be2e6a5330c6395a1f9f213edb0c8df (diff)
sparc32: Fix unaligned stack handling on trap return.
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>
Diffstat (limited to 'arch/sparc')
-rw-r--r--arch/sparc/mm/fault_32.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index bd8601601afa..5b836f5aea90 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -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);
}