kernel/git/stable/linux-stable.git/arch/s390/include, branch linux-3.16.y

s390: fix stfle zero padding

2019-10-31T22:14:56+00:00

commit 4f18d869ffd056c7858f3d617c71345cf19be008 upstream. The stfle inline assembly returns the number of double words written (condition code 0) or the double words it would have written (condition code 3), if the memory array it got as parameter would have been large enough. The current stfle implementation assumes that the array is always large enough and clears those parts of the array that have not been written to with a subsequent memset call. If however the array is not large enough memset will get a negative length parameter, which means that memset clears memory until it gets an exception and the kernel crashes. To fix this simply limit the maximum length. Move also the inline assembly to an extra function to avoid clobbering of register 0, which might happen because of the added min_t invocation together with code instrumentation. The bug was introduced with commit 14375bc4eb8d ("[S390] cleanup facility list handling") but was rather harmless, since it would only write to a rather large array. It became a potential problem with commit 3ab121ab1866 ("[S390] kernel: Add z/VM LGR detection"). Since then it writes to an array with only four double words, while some machines already deliver three double words. As soon as machines have a facility bit within the fifth double a crash on IPL would happen. Fixes: 14375bc4eb8d ("[S390] cleanup facility list handling") Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Ben Hutchings

locking/static_keys: Add a new static_key interface

2019-05-22T22:15:05+00:00

commit 11276d5306b8e5b438a36bbff855fe792d7eaa61 upstream. There are various problems and short-comings with the current static_key interface: - static_key_{true,false}() read like a branch depending on the key value, instead of the actual likely/unlikely branch depending on init value. - static_key_{true,false}() are, as stated above, tied to the static_key init values STATIC_KEY_INIT_{TRUE,FALSE}. - we're limited to the 2 (out of 4) possible options that compile to a default NOP because that's what our arch_static_branch() assembly emits. So provide a new static_key interface: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); Which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. This means adding a second arch_static_branch_jump() assembly helper which emits a JMP per default. In order to determine the right instruction for the right state, encode the branch type in the LSB of jump_entry::key. This is the final step in removing the naming confusion that has led to a stream of avoidable bugs such as: a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()") ... but it also allows new static key combinations that will give us performance enhancements in the subsequent patches. Tested-by: Rabin Vincent # arm Signed-off-by: Peter Zijlstra (Intel) Acked-by: Michael Ellerman # ppc Acked-by: Heiko Carstens # s390 Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.16: - For s390, use the 31-bit-compatible macros in arch_static_branch_jump() - Signed-off-by: Ben Hutchings

jump_label: Allow asm/jump_label.h to be included in assembly

2019-05-22T22:15:02+00:00

commit 55dd0df781e58ec23d218376ea4a676e7362a98c upstream. Wrap asm/jump_label.h for all archs with #ifndef __ASSEMBLY__. Since these are kernel only headers, we don't need #ifdef __KERNEL__ so can simplify things a bit. If an architecture wants to use jump labels in assembly, it will still need to define a macro to create the __jump_table entries (see ARCH_STATIC_BRANCH in the powerpc asm/jump_label.h for an example). Signed-off-by: Anton Blanchard Acked-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: benh@kernel.crashing.org Cc: catalin.marinas@arm.com Cc: davem@davemloft.net Cc: heiko.carstens@de.ibm.com Cc: jbaron@akamai.com Cc: linux@arm.linux.org.uk Cc: linuxppc-dev@lists.ozlabs.org Cc: liuj97@gmail.com Cc: mgorman@suse.de Cc: mmarek@suse.cz Cc: mpe@ellerman.id.au Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: schwidefsky@de.ibm.com Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1428551492-21977-1-git-send-email-anton@samba.org Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings

s390/jump label: use different nop instruction

2019-05-22T22:15:02+00:00

commit d5caa4dbf9bd2ad8cd7f6be0ca76722be947182b upstream. Use a brcl 0,2 instruction for jump label nops during compile time, so we don't mix up the different nops during mcount/hotpatch call site detection. The initial jump label code instruction replacement will exchange these instructions with either a branch or a brcl 0,0 instruction. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings

s390/mm: always force a load of the primary ASCE on context switch

2019-05-02T20:41:20+00:00

commit a38662084c8bdb829ff486468c7ea801c13fcc34 upstream. The ASCE of an mm_struct can be modified after a task has been created, e.g. via crst_table_downgrade for a compat process. The active_mm logic to avoid the switch_mm call if the next task is a kernel thread can lead to a situation where switch_mm is called where 'prev == next' is true but 'prev->context.asce == next->context.asce' is not. This can lead to a situation where a CPU uses the outdated ASCE to run a task. The result can be a crash, endless loops and really subtle problem due to TLBs being created with an invalid ASCE. Fixes: 53e857f30867 ("s390/mm,tlb: race of lazy TLB flush vs. recreation") Reported-by: Heiko Carstens Reviewed-by: Heiko Carstens Signed-off-by: Martin Schwidefsky [bwh: Backported to 3.16: - Keep the updates of mm_context_t::attach_count conditional on prev != next - Keep the update of mm_context_t::cpu_attach_mask conditional on both MACHINE_HAS_TLB_LC and prev != next - Adjust context] Signed-off-by: Ben Hutchings

s390/timex: fix get_tod_clock_ext() inline assembly

2019-02-11T17:53:13+00:00

commit e38f97813302065fbc9c9eab5c1a94dc021d71e2 upstream. For C language, it treats array parameter as a pointer, so sizeof for an array parameter is equal to sizeof for a pointer, which causes compiler warning (with allmodconfig by gcc 5): ./arch/s390/include/asm/timex.h: In function 'get_tod_clock_ext': ./arch/s390/include/asm/timex.h:76:32: warning: 'sizeof' on array function parameter 'clk' will return size of 'char *' [-Wsizeof-array-argument] typedef struct { char _[sizeof(clk)]; } addrtype; ^ Can use macro CLOCK_STORE_SIZE instead of all related hard code numbers, which also can avoid this warning. And also add a tab to CLOCK_TICK_RATE definition to match coding styles. [heiko.carstens@de.ibm.com]: Chen's patch actually fixes a bug within the get_tod_clock_ext() inline assembly where we incorrectly tell the compiler that only 8 bytes of memory get changed instead of 16 bytes. This would allow gcc to generate incorrect code. Right now this doesn't seem to be the case. Also slightly changed the patch a bit. - renamed CLOCK_STORE_SIZE to STORE_CLOCK_EXT_SIZE - changed get_tod_clock_ext() to receive a char pointer parameter Signed-off-by: Chen Gang Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings

s390/qdio: reset old sbal_state flags

2018-12-16T22:08:04+00:00

commit 64e03ff72623b8c2ea89ca3cb660094e019ed4ae upstream. When allocating a new AOB fails, handle_outbound() is still capable of transmitting the selected buffer (just without async completion). But if a previous transfer on this queue slot used async completion, its sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING. So when the upper layer driver sees this stale flag, it expects an async completion that never happens. Fix this by unconditionally clearing the flags field. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings

s390/cpum_sf: Add data entry sizes to sampling trailer entry

2018-11-20T18:04:51+00:00

commit 77715b7ddb446bd39a06f3376e85f4bb95b29bb8 upstream. The CPU Measurement sampling facility creates a trailer entry for each Sample-Data-Block of stored samples. The trailer entry contains the sizes (in bytes) of the stored sampling types: - basic-sampling data entry size - diagnostic-sampling data entry size Both sizes are 2 bytes long. This patch changes the trailer entry definition to reflect this. Fixes: fcc77f507333 ("s390/cpum_sf: Atomically reset trailer entry fields of sample-data-blocks") Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings

perf: fix invalid bit in diagnostic entry

2018-11-20T18:04:51+00:00

commit 3c0a83b14ea71fef5ccc93a3bd2de5f892be3194 upstream. The s390 CPU measurement facility sampling mode supports basic entries and diagnostic entries. Each entry has a valid bit to indicate the status of the entry as valid or invalid. This bit is bit 31 in the diagnostic entry, but the bit mask definition refers to bit 30. Fix this by making the reserved field one bit larger. Fixes: 7e75fc3ff4cf ("s390/cpum_sf: Add raw data sampling to support the diagnostic-sampling function") Signed-off-by: Thomas Richter Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky Signed-off-by: Ben Hutchings

Make asm/word-at-a-time.h available on all architectures

2018-10-21T07:46:11+00:00

commit a6e2f029ae34f41adb6ae3812c32c5d326e1abd2 upstream. Added the x86 implementation of word-at-a-time to the generic version, which previously only supported big-endian. Omitted the x86-specific load_unaligned_zeropad(), which in any case is also not present for the existing BE-only implementation of a word-at-a-time, and is only used under CONFIG_DCACHE_WORD_ACCESS. Added as a "generic-y" to the Kbuilds of all architectures that didn't previously have it. Signed-off-by: Chris Metcalf [bwh: Backported to 3.16: - Drop change in arch/nios2 - Adjust context] Signed-off-by: Ben Hutchings