kernel/linux.git, branch v3.18.17

Linux 3.18.17

2015-06-28T17:40:40+00:00

Signed-off-by: Sasha Levin

kernel: make READ_ONCE() valid on const arguments

2015-06-28T17:39:28+00:00

[ Upstream commit dd36929720f40f17685e841ae0d4c581c165ea60 ] The use of READ_ONCE() causes lots of warnings witht he pending paravirt spinlock fixes, because those ends up having passing a member to a 'const' structure to READ_ONCE(). There should certainly be nothing wrong with using READ_ONCE() with a const source, but the helper function __read_once_size() would cause warnings because it would drop the 'const' qualifier, but also because the destination would be marked 'const' too due to the use of 'typeof'. Use a union of types in READ_ONCE() to avoid this issue. Also make sure to use parenthesis around the macro arguments to avoid possible operator precedence issues. Tested-by: Ingo Molnar Cc: Christian Borntraeger Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

KVM: VMX: Preserve host CR4.MCE value while in guest mode.

2015-06-28T17:39:27+00:00

[ Upstream commit 085e68eeafbf76e21848ad5bafaecec88a11dd64 ] The host's decision to enable machine check exceptions should remain in force during non-root mode. KVM was writing 0 to cr4 on VCPU reset and passed a slightly-modified 0 to the vmcs.guest_cr4 value. Tested: Built. On earlier version, tested by injecting machine check while a guest is spinning. Before the change, if guest CR4.MCE==0, then the machine check is escalated to Catastrophic Error (CATERR) and the machine dies. If guest CR4.MCE==1, then the machine check causes VMEXIT and is handled normally by host Linux. After the change, injecting a machine check causes normal Linux machine check handling. Signed-off-by: Ben Serebrin Reviewed-by: Venkatesh Srinivas Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin

x86: Store a per-cpu shadow copy of CR4

2015-06-28T17:39:27+00:00

[ Upstream commit 1e02ce4cccdcb9688386e5b8d2c9fa4660b45389 ] Context switches and TLB flushes can change individual bits of CR4. CR4 reads take several cycles, so store a shadow copy of CR4 in a per-cpu variable. To avoid wasting a cache line, I added the CR4 shadow to cpu_tlbstate, which is already touched in switch_mm. The heaviest users of the cr4 shadow will be switch_mm and __switch_to_xtra, and __switch_to_xtra is called shortly after switch_mm during context switch, so the cacheline is likely to be hot. Signed-off-by: Andy Lutomirski Reviewed-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Cc: Kees Cook Cc: Andrea Arcangeli Cc: Vince Weaver Cc: "hillf.zj" Cc: Valdis Kletnieks Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Linus Torvalds Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

x86: Clean up cr4 manipulation

2015-06-28T17:39:27+00:00

[ Upstream commit 375074cc736ab1d89a708c0a8d7baa4a70d5d476 ] CR4 manipulation was split, seemingly at random, between direct (write_cr4) and using a helper (set/clear_in_cr4). Unfortunately, the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code, which only a small subset of users actually wanted. This patch replaces all cr4 access in functions that don't leave cr4 exactly the way they found it with new helpers cr4_set_bits, cr4_clear_bits, and cr4_set_bits_and_update_boot. Signed-off-by: Andy Lutomirski Reviewed-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Cc: Andrea Arcangeli Cc: Vince Weaver Cc: "hillf.zj" Cc: Valdis Kletnieks Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Kees Cook Cc: Linus Torvalds Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

spi: bitbang: Make setup_transfer() callback optional

2015-06-28T17:39:27+00:00

[ Upstream commit 7d0ec8b6f40b356f780b79de63eeafd6b907d68c ] Some controller drivers have no need of this callback (spi-altera even causes a NULL pointer dereference because it doesn't register the callback, falsely assuming that it is already optional). Fixes: 30af9b558a56 ("spi/bitbang: Drop empty setup() functions") Signed-off-by: Pelle Nilsson Reviewed-by: Ezequiel Garcia Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

dmaengine: shdmac: avoid unused variable warnings

2015-06-28T17:39:26+00:00

[ Upstream commit 7d3beab16dd9eee86bb1a4dd05b51159fc7772f0 ] This driver uses '#ifdef CONFIG_ARCH_SHMOBILE' and '#ifdef CONFIG_ARM' interchangeably in its sh_dmae_probe function, which causes a build warning when building for ARM without also enabling shmobile: dma/sh/shdmac.c: In function sh_dmae_probe: dma/sh/shdmac.c:696:6: warning: unused variable errirq [-Wunused-variable] dma/sh/shdmac.c:695:16: warning: unused variable irqflags [-Wunused-variable] dma/sh/shdmac.c: At top level: dma/sh/shdmac.c:447:20: warning: sh_dmae_err defined but not used [-Wunused-function] This changes all the #ifdef to test for CONFIG_ARCH_SHMOBILE to avoid that warning. An earlier patch from Laurent had fixed the warning for non-ARM case, but it still remained present in ARM randconfig builds. Signed-off-by: Arnd Bergmann Fixes: 52d6a5ee101bf ("DMA: shdma: Fix warnings due to declared but unused symbols") Acked-by: Laurent Pinchart Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

tcp: tcp_get_info() should fetch socket fields once

2015-06-28T17:39:26+00:00

[ Upstream commit fad9dfefea6405039491e7e4fc21fb6e59e7d26c ] tcp_get_info() can be called without holding socket lock, so any socket fields can change under us. Use READ_ONCE() to fetch sk_pacing_rate and sk_max_pacing_rate Fixes: 977cb0ecf82e ("tcp: add pacing_rate information into tcp_info") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr

2015-06-28T17:39:26+00:00

[ Upstream commit 98b228f55014870092c15d7d168fecac69f2f12a ] Until now, the EFI stub was only setting the 32 bit cmd_line_ptr in the setup_header structure, so on 64 bit platforms this could be truncated. This patch adds setting the upper bits of the buffer address in ext_cmd_line_ptr. This case was likely never hit, as the allocation for this buffer is done at the lowest available address. Only x86_64 kernels have this problem, as the 1-1 mapping mandated by EFI ensures that all memory is 32 bit addressable on 32 bit platforms. The EFI stub does not support mixed mode, so the 32 bit kernel on 64 bit firmware case does not need to be handled. Signed-off-by: Roy Franz Cc: Signed-off-by: Matt Fleming Signed-off-by: Sasha Levin

efivarfs: Ensure VariableName is NUL-terminated

2015-06-28T17:39:26+00:00

[ Upstream commit c57dcb566d3d866a302a1da2e06344bec31d5bcd ] Some buggy firmware implementations update VariableNameSize on success such that it does not include the final NUL character which results in garbage in the efivarfs name entries. Use kzalloc on the efivar_entry (as is done in efivars.c) to ensure that the name is always NUL-terminated. The buggy firmware is: BIOS Information Vendor: Intel Corp. Version: S1200RP.86B.02.02.0005.102320140911 Release Date: 10/23/2014 BIOS Revision: 4.6 System Information Manufacturer: Intel Corporation Product Name: S1200RP_SE Signed-off-by: Ross Lagerwall Acked-by: Matthew Garrett Cc: Jeremy Kerr Cc: Signed-off-by: Matt Fleming Signed-off-by: Sasha Levin