From: Jeremy Kerr Date: Mon, 10 Nov 2008 23:22:22 +0000 (+1100) Subject: powerpc/spufs: Fix spinning in spufs_ps_fault on signal X-Git-Tag: v3.12-rc1~17069^2~6^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=606572634c3faa5b32a8fc430266e6e9d78d2179;p=kernel%2Fkernel-generic.git powerpc/spufs: Fix spinning in spufs_ps_fault on signal Currently, we can end up in an infinite loop if we get a signal while the kernel has faulted in spufs_ps_fault. Eg: alarm(1); write(fd, some_spu_psmap_register_address, 4); - the write's copy_from_user will fault on the ps mapping, and signal_pending will be non-zero. Because returning from the fault handler will never clear TIF_SIGPENDING, so we'll just keep faulting, resulting in an unkillable process using 100% of CPU. This change returns VM_FAULT_SIGBUS if there's a fatal signal pending, letting us escape the loop. Signed-off-by: Jeremy Kerr --- diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index b73c369..1b26071 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -390,6 +390,9 @@ static int spufs_ps_fault(struct vm_area_struct *vma, if (offset >= ps_size) return VM_FAULT_SIGBUS; + if (fatal_signal_pending(current)) + return VM_FAULT_SIGBUS; + /* * Because we release the mmap_sem, the context may be destroyed while * we're in spu_wait. Grab an extra reference so it isn't destroyed