kernel.git/arch/powerpc, branch linux-3.11.y

compiler/gcc4: Add quirk for 'asm goto' miscompilation bug

2013-10-18T17:54:57Z

commit 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 upstream. Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu Reported-by: Oleg Nesterov Reported-by: Peter Zijlstra Suggested-by: Jakub Jelinek Reviewed-by: Richard Henderson Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/20131015062351.GA4666@gmail.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S HV: Fix typo in saving DSCR

2013-10-18T17:54:55Z

commit cfc860253abd73e1681696c08ea268d33285a2c4 upstream. This fixes a typo in the code that saves the guest DSCR (Data Stream Control Register) into the kvm_vcpu_arch struct on guest exit. The effect of the typo was that the DSCR value was saved in the wrong place, so changes to the DSCR by the guest didn't persist across guest exit and entry, and some host kernel memory got corrupted. Signed-off-by: Paul Mackerras Acked-by: Alexander Graf Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

powerpc: Restore registers on error exit from csum_partial_copy_generic()

2013-10-14T01:14:28Z

commit 8f21bd0090052e740944f9397e2be5ac7957ded7 upstream. The csum_partial_copy_generic() function saves the PowerPC non-volatile r14, r15, and r16 registers for the main checksum-and-copy loop. Unfortunately, it fails to restore them upon error exit from this loop, which results in silent corruption of these registers in the presumably rare event of an access exception within that loop. This commit therefore restores these register on error exit from the loop. Signed-off-by: Paul E. McKenney Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc/sysfs: Disable writing to PURR in guest mode

2013-10-14T01:14:28Z

commit d1211af3049f4c9c1d8d4eb8f8098cc4f4f0d0c7 upstream. arch/powerpc/kernel/sysfs.c exports PURR with write permission. This may be valid for kernel in phyp mode. But writing to the file in guest mode causes crash due to a priviledge violation Signed-off-by: Madhavan Srinivasan Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc: Fix memory hotplug with sparse vmemmap

2013-10-14T01:14:28Z

commit f7e3334a6bcb42e7295a9bd9cb36ca4e6e4e66b4 upstream. Previous commit 46723bfa540... introduced a new config option HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc when sparse vmemmap is not defined. This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to register_page_bootmem_info_node. Without this we get a BUG_ON for memory hot remove in put_page_bootmem(). This also adds a stub for register_page_bootmem_memmap to allow ppc to build with sparse vmemmap defined. Leaving this as a stub is fine since the same vmemmap addresses are also handled in vmemmap_populate and as such are properly mapped. Signed-off-by: Nathan Fontenot Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc: Fix parameter clobber in csum_partial_copy_generic()

2013-10-14T01:14:28Z

commit d9813c3681a36774b254c0cdc9cce53c9e22c756 upstream. The csum_partial_copy_generic() uses register r7 to adjust the remaining bytes to process. Unfortunately, r7 also holds a parameter, namely the address of the flag to set in case of access exceptions while reading the source buffer. Lacking a quantum implementation of PowerPC, this commit instead uses register r9 to do the adjusting, leaving r7's pointer uncorrupted. Signed-off-by: Paul E. McKenney Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc/vio: Fix modalias_show return values

2013-10-14T01:14:28Z

commit e82b89a6f19bae73fb064d1b3dd91fcefbb478f4 upstream. modalias_show() should return an empty string on error, not -ENODEV. This causes the following false and annoying error: > find /sys/devices -name modalias -print0 | xargs -0 cat >/dev/null cat: /sys/devices/vio/4000/modalias: No such device cat: /sys/devices/vio/4001/modalias: No such device cat: /sys/devices/vio/4002/modalias: No such device cat: /sys/devices/vio/4004/modalias: No such device cat: /sys/devices/vio/modalias: No such device Signed-off-by: Prarit Bhargava Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Turn interrupts hard off in tm_reclaim()

2013-10-14T01:14:28Z

commit c69e63b0f135fa51d6e1c38b5ac8a1def15ea3fa upstream. We can't take IRQs in tm_reclaim as we might have a bogus r13 and r1. This turns IRQs hard off in this function. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Switch out userspace PPR and DSCR sooner

2013-10-14T01:14:28Z

commit e9bdc3d6143d1c4b8d8ce5231fc958268331f983 upstream. When we do a treclaim or trecheckpoint we end up running with userspace PPR and DSCR values. Currently we don't do anything special to avoid running with user values which could cause a severe performance degradation. This patch moves the PPR and DSCR save and restore around treclaim and trecheckpoint so that we run with user values for a much shorter period. More care is taken with the PPR as it's impact is greater than the DSCR. This is similar to user exceptions, where we run HTM_MEDIUM early to ensure that we don't run with a userspace PPR values in the kernel. Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

powerpc/perf: Fix handling of FAB events

2013-10-14T01:14:28Z

commit a53b27b3abeef406de92a2bb0ceb6fb4c3fb8fc4 upstream. Commit 4df4899 "Add power8 EBB support" included a bug in the handling of the FAB_CRESP_MATCH and FAB_TYPE_MATCH fields. These values are pulled out of the event code using EVENT_THR_CTL_SHIFT, however we were then or'ing that value directly into MMCR1. This meant we were failing to set the FAB fields correctly, and also potentially corrupting the value for PMC4SEL. Leading to no counts for the FAB events and incorrect counts for PMC4. The fix is simply to shift left the FAB value correctly before or'ing it with MMCR1. Reported-by: Sooraj Ravindran Nair Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman