Commit
4c2de74cc869 ("powerpc/64: Interrupts save PPR on stack rather
than thread_struct") changed sizeof(struct pt_regs) % 16 from 0 to 8,
which causes the interrupt frame allocation on kernel entry to put the
kernel stack out of alignment.
Quadword (16-byte) alignment for the stack is required by both the
64-bit v1 ABI (v1.9 § 3.2.2) and the 64-bit v2 ABI (v1.1 § 2.2.2.1).
Add a pad field to fix alignment, and add a BUILD_BUG_ON to catch this
in future.
Fixes:
4c2de74cc869 ("powerpc/64: Interrupts save PPR on stack rather than thread_struct")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#ifdef CONFIG_PPC64
unsigned long ppr;
+ unsigned long __pad; /* Maintain 16 byte interrupt stack alignment */
#endif
};
#endif
{
unsigned long pa;
+ BUILD_BUG_ON(STACK_INT_FRAME_SIZE % 16);
+
pa = memblock_alloc_base_nid(THREAD_SIZE, THREAD_SIZE, limit,
early_cpu_to_node(cpu), MEMBLOCK_NONE);
if (!pa) {