- Linux-stable-mirror - lists.linaro.org

[PATCH] block: do not use interruptible wait anywhere

by Khalid Elmously

From: Alan Jenkins <alan.christopher.jenkins(a)gmail.com> BugLink: http://bugs.launchpad.net/bugs/1776887 When blk_queue_enter() waits for a queue to unfreeze, or unset the PREEMPT_ONLY flag, do not allow it to be interrupted by a signal. The PREEMPT_ONLY flag was introduced later in commit 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably"). Note the SCSI device is resumed asynchronously, i.e. after un-freezing userspace tasks. So that commit exposed the bug as a regression in v4.15. A mysterious SIGBUS (or -EIO) sometimes happened during the time the device was being resumed. Most frequently, there was no kernel log message, and we saw Xorg or Xwayland killed by SIGBUS.[1] [1] E.g. https://bugzilla.redhat.com/show_bug.cgi?id=1553979 Without this fix, I get an IO error in this test: # dd if=/dev/sda of=/dev/null iflag=direct & \ while killall -SIGUSR1 dd; do sleep 0.1; done & \ echo mem > /sys/power/state ; \ sleep 5; killall dd # stop after 5 seconds The interruptible wait was added to blk_queue_enter in commit 3ef28e83ab15 ("block: generic request_queue reference counting"). Before then, the interruptible wait was only in blk-mq, but I don't think it could ever have been correct. Reviewed-by: Bart Van Assche <bart.vanassche(a)wdc.com> Cc: stable(a)vger.kernel.org Signed-off-by: Alan Jenkins <alan.christopher.jenkins(a)gmail.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> (cherry-picked from 1dc3039bc87ae7d19a990c3ee71cfd8a9068f428) Signed-off-by: Khalid Elmously <khalid.elmously(a)canonical.com> --- block/blk-core.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index fc0666354af3..59c91e345eea 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -821,7 +821,6 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) while (true) { bool success = false; - int ret; rcu_read_lock(); if (percpu_ref_tryget_live(&q->q_usage_counter)) { @@ -853,14 +852,12 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) */ smp_rmb(); - ret = wait_event_interruptible(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && - (preempt || !blk_queue_preempt_only(q))) || - blk_queue_dying(q)); + wait_event(q->mq_freeze_wq, + (atomic_read(&q->mq_freeze_depth) == 0 && + (preempt || !blk_queue_preempt_only(q))) || + blk_queue_dying(q)); if (blk_queue_dying(q)) return -ENODEV; - if (ret) - return ret; } } -- 2.17.1

7 years, 3 months

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v3.2.102 build: 5 failures 20 warnings (v3.2.102)

by Build bot for Mark Brown

Tree/Branch: v3.2.102 Git describe: v3.2.102 Commit: f63b2b3204 Linux 3.2.102 Build Time: 0 min 3 sec Passed: 0 / 5 ( 0.00 %) Failed: 5 / 5 (100.00 %) Errors: 6 Warnings: 20 Section Mismatches: 0 Failed defconfigs: x86_64-allnoconfig arm-allmodconfig arm-allnoconfig x86_64-allmodconfig x86_64-defconfig Errors: x86_64-allnoconfig /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode arm-allnoconfig /home/broonie/build/linux-stable/arch/arm/include/asm/div64.h:77:7: error: '__LINUX_ARM_ARCH__' undeclared (first use in this function) /home/broonie/build/linux-stable/arch/arm/include/asm/glue-cache.h:129:2: error: #error Unknown cache maintenance model /home/broonie/build/linux-stable/arch/arm/include/asm/glue-df.h:107:2: error: #error Unknown data abort handler type /home/broonie/build/linux-stable/arch/arm/include/asm/glue-pf.h:54:2: error: #error Unknown prefetch abort handler type x86_64-allmodconfig /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode x86_64-defconfig /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode ------------------------------------------------------------------------------- defconfigs with issues (other than build errors): 2 warnings 0 mismatches : arm-allmodconfig 19 warnings 0 mismatches : arm-allnoconfig ------------------------------------------------------------------------------- Errors summary: 6 3 /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode 3 /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode 1 /home/broonie/build/linux-stable/arch/arm/include/asm/glue-pf.h:54:2: error: #error Unknown prefetch abort handler type 1 /home/broonie/build/linux-stable/arch/arm/include/asm/glue-df.h:107:2: error: #error Unknown data abort handler type 1 /home/broonie/build/linux-stable/arch/arm/include/asm/glue-cache.h:129:2: error: #error Unknown cache maintenance model 1 /home/broonie/build/linux-stable/arch/arm/include/asm/div64.h:77:7: error: '__LINUX_ARM_ARCH__' undeclared (first use in this function) Warnings Summary: 20 2 .config:27:warning: symbol value '' invalid for PHYS_OFFSET 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:342:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:272:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:265:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:131:35: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:127:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:121:3: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:120:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:114:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/swab.h:25:28: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/processor.h:82:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/processor.h:102:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/irqflags.h:11:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/fpstate.h:32:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/cachetype.h:33:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/cachetype.h:28:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/cacheflush.h:196:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/cacheflush.h:194:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/bitops.h:217:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] 1 /home/broonie/build/linux-stable/arch/arm/include/asm/atomic.h:30:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] =============================================================================== Detailed per-defconfig build reports below: ------------------------------------------------------------------------------- x86_64-allnoconfig : FAIL, 2 errors, 0 warnings, 0 section mismatches Errors: /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode ------------------------------------------------------------------------------- arm-allmodconfig : FAIL, 0 errors, 2 warnings, 0 section mismatches Warnings: .config:27:warning: symbol value '' invalid for PHYS_OFFSET .config:27:warning: symbol value '' invalid for PHYS_OFFSET ------------------------------------------------------------------------------- arm-allnoconfig : FAIL, 4 errors, 19 warnings, 0 section mismatches Errors: /home/broonie/build/linux-stable/arch/arm/include/asm/div64.h:77:7: error: '__LINUX_ARM_ARCH__' undeclared (first use in this function) /home/broonie/build/linux-stable/arch/arm/include/asm/glue-cache.h:129:2: error: #error Unknown cache maintenance model /home/broonie/build/linux-stable/arch/arm/include/asm/glue-df.h:107:2: error: #error Unknown data abort handler type /home/broonie/build/linux-stable/arch/arm/include/asm/glue-pf.h:54:2: error: #error Unknown prefetch abort handler type Warnings: /home/broonie/build/linux-stable/arch/arm/include/asm/irqflags.h:11:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:114:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:120:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:121:3: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:127:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:131:35: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:265:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:272:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/system.h:342:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/bitops.h:217:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/swab.h:25:28: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/fpstate.h:32:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/processor.h:82:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/processor.h:102:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/atomic.h:30:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/cachetype.h:28:5: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/cachetype.h:33:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/cacheflush.h:194:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] /home/broonie/build/linux-stable/arch/arm/include/asm/cacheflush.h:196:7: warning: "__LINUX_ARM_ARCH__" is not defined [-Wundef] ------------------------------------------------------------------------------- x86_64-allmodconfig : FAIL, 2 errors, 0 warnings, 0 section mismatches Errors: /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode ------------------------------------------------------------------------------- x86_64-defconfig : FAIL, 2 errors, 0 warnings, 0 section mismatches Errors: /home/broonie/build/linux-stable/scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode /home/broonie/build/linux-stable/kernel/bounds.c:1:0: error: code model kernel does not support PIC mode ------------------------------------------------------------------------------- Passed with no errors, warnings or mismatches:

7 years, 3 months

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v3.18.113 build: 0 failures 1 warnings (v3.18.113)

by Build bot for Mark Brown

Tree/Branch: v3.18.113 Git describe: v3.18.113 Commit: 31767764c0 Linux 3.18.113 Build Time: 45 min 57 sec Passed: 10 / 10 (100.00 %) Failed: 0 / 10 ( 0.00 %) Errors: 0 Warnings: 1 Section Mismatches: 0 ------------------------------------------------------------------------------- defconfigs with issues (other than build errors): 7 warnings 0 mismatches : x86_64-allmodconfig 2 warnings 0 mismatches : x86_64-defconfig ------------------------------------------------------------------------------- Warnings Summary: 1 9 ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] =============================================================================== Detailed per-defconfig build reports below: ------------------------------------------------------------------------------- x86_64-allmodconfig : PASS, 0 errors, 7 warnings, 0 section mismatches Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ------------------------------------------------------------------------------- x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ------------------------------------------------------------------------------- Passed with no errors, warnings or mismatches: arm64-allnoconfig arm64-allmodconfig arm-multi_v5_defconfig arm-multi_v7_defconfig arm-allmodconfig arm-allnoconfig x86_64-allnoconfig arm64-defconfig

7 years, 3 months

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[PATCH 4.9 1/2] Revert "Btrfs: fix scrub to repair raid6 corruption"

by Sasha Levin

This reverts commit 186a6519dc94964a4c5c68fca482f20f71551f26. This commit used an incorrect log message. Signed-off-by: Sasha Levin <alexander.levin(a)microsoft.com> --- fs/btrfs/raid56.c | 18 ++++-------------- fs/btrfs/volumes.c | 9 +-------- 2 files changed, 5 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index af6a776fa18c..d016d4a79864 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -2161,21 +2161,11 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio, } /* - * Loop retry: - * for 'mirror == 2', reconstruct from all other stripes. - * for 'mirror_num > 2', select a stripe to fail on every retry. + * reconstruct from the q stripe if they are + * asking for mirror 3 */ - if (mirror_num > 2) { - /* - * 'mirror == 3' is to fail the p stripe and - * reconstruct from the q stripe. 'mirror > 3' is to - * fail a data stripe and reconstruct from p+q stripe. - */ - rbio->failb = rbio->real_stripes - (mirror_num - 1); - ASSERT(rbio->failb > 0); - if (rbio->failb <= rbio->faila) - rbio->failb--; - } + if (mirror_num == 3) + rbio->failb = rbio->real_stripes - 2; ret = lock_stripe_add(rbio); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 76017e1b3c0f..c2495cde26f6 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5186,14 +5186,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) else if (map->type & BTRFS_BLOCK_GROUP_RAID5) ret = 2; else if (map->type & BTRFS_BLOCK_GROUP_RAID6) - /* - * There could be two corrupted data stripes, we need - * to loop retry in order to rebuild the correct data. - * - * Fail a stripe at a time on every retry except the - * stripe under reconstruction. - */ - ret = map->num_stripes; + ret = 3; else ret = 1; free_extent_map(em); -- 2.17.1

7 years, 3 months

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[PATCH 4.14 1/3] Revert "Btrfs: fix scrub to repair raid6 corruption"

by Sasha Levin

This reverts commit d91bb7c6988bd6450284c762b33f2e1ea3fe7c97. This commit used an incorrect log message. Signed-off-by: Sasha Levin <alexander.levin(a)microsoft.com> --- fs/btrfs/raid56.c | 18 ++++-------------- fs/btrfs/volumes.c | 9 +-------- 2 files changed, 5 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 2e995e565633..d1bda68a3386 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -2172,21 +2172,11 @@ int raid56_parity_recover(struct btrfs_fs_info *fs_info, struct bio *bio, } /* - * Loop retry: - * for 'mirror == 2', reconstruct from all other stripes. - * for 'mirror_num > 2', select a stripe to fail on every retry. + * reconstruct from the q stripe if they are + * asking for mirror 3 */ - if (mirror_num > 2) { - /* - * 'mirror == 3' is to fail the p stripe and - * reconstruct from the q stripe. 'mirror > 3' is to - * fail a data stripe and reconstruct from p+q stripe. - */ - rbio->failb = rbio->real_stripes - (mirror_num - 1); - ASSERT(rbio->failb > 0); - if (rbio->failb <= rbio->faila) - rbio->failb--; - } + if (mirror_num == 3) + rbio->failb = rbio->real_stripes - 2; ret = lock_stripe_add(rbio); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 08afafb6ecf7..69bc37a87c5a 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5110,14 +5110,7 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) else if (map->type & BTRFS_BLOCK_GROUP_RAID5) ret = 2; else if (map->type & BTRFS_BLOCK_GROUP_RAID6) - /* - * There could be two corrupted data stripes, we need - * to loop retry in order to rebuild the correct data. - * - * Fail a stripe at a time on every retry except the - * stripe under reconstruction. - */ - ret = map->num_stripes; + ret = 3; else ret = 1; free_extent_map(em); -- 2.17.1

7 years, 3 months

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[patch 04/27] mm: fix devmem_is_allowed() for sub-page System RAM intersections

by akpm＠linux-foundation.org

From: Dan Williams <dan.j.williams(a)intel.com> Subject: mm: fix devmem_is_allowed() for sub-page System RAM intersections Hussam reports: I was poking around and for no real reason, I did cat /dev/mem and strings /dev/mem. Then I saw the following warning in dmesg. I saved it and rebooted immediately. memremap attempted on mixed range 0x000000000009c000 size: 0x1000 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 11810 at kernel/memremap.c:98 memremap+0x104/0x170 [..] Call Trace: xlate_dev_mem_ptr+0x25/0x40 read_mem+0x89/0x1a0 __vfs_read+0x36/0x170 The memremap() implementation checks for attempts to remap System RAM with MEMREMAP_WB and instead redirects those mapping attempts to the linear map. However, that only works if the physical address range being remapped is page aligned. In low memory we have situations like the following: 00000000-00000fff : Reserved 00001000-0009fbff : System RAM 0009fc00-0009ffff : Reserved ...where System RAM intersects Reserved ranges on a sub-page page granularity. Given that devmem_is_allowed() special cases any attempt to map System RAM in the first 1MB of memory, replace page_is_ram() with the more precise region_intersects() to trap attempts to map disallowed ranges. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199999 Link: http://lkml.kernel.org/r/152856436164.18127.2847888121707136898.stgit@dwill… Fixes: 92281dee825f ("arch: introduce memremap()") Signed-off-by: Dan Williams <dan.j.williams(a)intel.com> Reported-by: Hussam Al-Tayeb <me(a)hussam.eu.org> Tested-by: Hussam Al-Tayeb <me(a)hussam.eu.org> Cc: Christoph Hellwig <hch(a)lst.de> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/mm/init.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff -puN arch/x86/mm/init.c~mm-fix-devmem_is_allowed-for-sub-page-system-ram-intersections arch/x86/mm/init.c --- a/arch/x86/mm/init.c~mm-fix-devmem_is_allowed-for-sub-page-system-ram-intersections +++ a/arch/x86/mm/init.c @@ -706,7 +706,9 @@ void __init init_mem_mapping(void) */ int devmem_is_allowed(unsigned long pagenr) { - if (page_is_ram(pagenr)) { + if (region_intersects(PFN_PHYS(pagenr), PAGE_SIZE, + IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE) + != REGION_DISJOINT) { /* * For disallowed memory regions in the low 1MB range, * request that the page be shown as all zeros. _

7 years, 3 months

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[patch 01/27] mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm()

by akpm＠linux-foundation.org

From: Jia He <jia.he(a)hxt-semitech.com> Subject: mm/ksm.c: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm() In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by PAGE_SIZE unaligned for rmap_item->address under memory pressure tests(start 20 guests and run memhog in the host). --------------------------begin-------------------------------------- [ 410.853828] WARNING: CPU: 4 PID: 4641 at arch/arm64/kvm/../../../virt/kvm/arm/mmu.c:1826 kvm_age_hva_handler+0xc0/0xc8 [ 410.864518] Modules linked in: vhost_net vhost tap xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_umad rdma_cm ib_cm iw_cm mlx5_ib vfat fat ib_uverbs dm_mirror dm_region_hash ib_core dm_log dm_mod crc32_ce ipmi_ssif sg nfsd [ 410.935101] auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx5_core ixgbe mlxfw devlink mdio ahci_platform libahci_platform qcom_emac libahci hdma hdma_mgmt i2c_qup [ 410.951369] CPU: 4 PID: 4641 Comm: memhog Tainted: G W 4.17.0-rc3+ #8 [ 410.959104] Hardware name: <snip for confidential issues> [ 410.969791] pstate: 80400005 (Nzcv daif +PAN -UAO) [ 410.974575] pc : kvm_age_hva_handler+0xc0/0xc8 [ 410.979012] lr : handle_hva_to_gpa+0xa8/0xe0 [ 410.983274] sp : ffff801761553290 [ 410.986581] x29: ffff801761553290 x28: 0000000000000000 [ 410.991888] x27: 0000000000000002 x26: 0000000000000000 [ 410.997195] x25: ffff801765430058 x24: ffff0000080b5608 [ 411.002501] x23: 0000000000000000 x22: ffff8017ccb84000 [ 411.007807] x21: 0000000003ff0000 x20: ffff8017ccb84000 [ 411.013113] x19: 000000000000fe00 x18: ffff000008fb3c08 [ 411.018419] x17: 0000000000000000 x16: 0060001645820bd3 [ 411.023725] x15: ffff80176aacbc08 x14: 0000000000000000 [ 411.029031] x13: 0000000000000040 x12: 0000000000000228 [ 411.034337] x11: 0000000000000000 x10: 0000000000000000 [ 411.039643] x9 : 0000000000000010 x8 : 0000000000000004 [ 411.044949] x7 : 0000000000000000 x6 : 00008017f0770000 [ 411.050255] x5 : 0000fffda59f0200 x4 : 0000000000000000 [ 411.055561] x3 : 0000000000000000 x2 : 000000000000fe00 [ 411.060867] x1 : 0000000003ff0000 x0 : 0000000020000000 [ 411.066173] Call trace: [ 411.068614] kvm_age_hva_handler+0xc0/0xc8 [ 411.072703] handle_hva_to_gpa+0xa8/0xe0 [ 411.076619] kvm_age_hva+0x4c/0xe8 [ 411.080014] kvm_mmu_notifier_clear_flush_young+0x54/0x98 [ 411.085408] __mmu_notifier_clear_flush_young+0x6c/0xa0 [ 411.090627] page_referenced_one+0x154/0x1d8 [ 411.094890] rmap_walk_ksm+0x12c/0x1d0 [ 411.098632] rmap_walk+0x94/0xa0 [ 411.101854] page_referenced+0x194/0x1b0 [ 411.105770] shrink_page_list+0x674/0xc28 [ 411.109772] shrink_inactive_list+0x26c/0x5b8 [ 411.114122] shrink_node_memcg+0x35c/0x620 [ 411.118211] shrink_node+0x100/0x430 [ 411.121778] do_try_to_free_pages+0xe0/0x3a8 [ 411.126041] try_to_free_pages+0xe4/0x230 [ 411.130045] __alloc_pages_nodemask+0x564/0xdc0 [ 411.134569] alloc_pages_vma+0x90/0x228 [ 411.138398] do_anonymous_page+0xc8/0x4d0 [ 411.142400] __handle_mm_fault+0x4a0/0x508 [ 411.146489] handle_mm_fault+0xf8/0x1b0 [ 411.150321] do_page_fault+0x218/0x4b8 [ 411.154064] do_translation_fault+0x90/0xa0 [ 411.158239] do_mem_abort+0x68/0xf0 [ 411.161721] el0_da+0x24/0x28 ---------------------------end--------------------------------------- In rmap_walk_ksm, the rmap_item->address might still have the STABLE_FLAG, then the start and end in handle_hva_to_gpa might not be PAGE_SIZE aligned. Thus it will cause exceptions in handle_hva_to_gpa on arm64. This patch fixes it by ignoring (not removing) the low bits of address when doing rmap_walk_ksm. IMO, it should be backported to stable tree. the stom of WARN_ONs is very easy for me to reproduce. More than that, I watched a panic (not reproducible) as follows: [35380.805825] page:ffff7fe003742d80 count:-4871 mapcount:-2126053375 mapping: (null) index:0x0 [35380.815024] flags: 0x1fffc00000000000() [35380.818845] raw: 1fffc00000000000 0000000000000000 0000000000000000 ffffecf981470000 [35380.826569] raw: dead000000000100 dead000000000200 ffff8017c001c000 0000000000000000 [35380.834294] page dumped because: nonzero _refcount [35380.839069] Modules linked in: vhost_net vhost tap ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter fcoe libfcoe libfc 8021q garp mrp stp llc scsi_transport_fc openvswitch nf_conntrack_ipv6 nf_nat_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_defrag_ipv6 nf_nat nf_conntrack vfat fat rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm mlx5_ib ib_core crc32_ce ipmi_ssif tpm_tis tpm_tis_core sg nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c mlx5_core mlxfw devlink ahci_platform libahci_platform libahci qcom_emac sdhci_acpi sdhci hdma mmc_core hdma_mgmt i2c_qup dm_mirror dm_region_hash dm_log dm_mod [35380.908341] CPU: 29 PID: 18323 Comm: qemu-kvm Tainted: G W 4.14.15-5.hxt.aarch64 #1 [35380.917107] Hardware name: <snip for confidential issues> [35380.930909] Call trace: [35380.933345] [<ffff000008088f00>] dump_backtrace+0x0/0x22c [35380.938723] [<ffff000008089150>] show_stack+0x24/0x2c [35380.943759] [<ffff00000893c078>] dump_stack+0x8c/0xb0 [35380.948794] [<ffff00000820ab50>] bad_page+0xf4/0x154 [35380.953740] [<ffff000008211ce8>] free_pages_check_bad+0x90/0x9c [35380.959642] [<ffff00000820c430>] free_pcppages_bulk+0x464/0x518 [35380.965545] [<ffff00000820db98>] free_hot_cold_page+0x22c/0x300 [35380.971448] [<ffff0000082176fc>] __put_page+0x54/0x60 [35380.976484] [<ffff0000080b1164>] unmap_stage2_range+0x170/0x2b4 [35380.982385] [<ffff0000080b12d8>] kvm_unmap_hva_handler+0x30/0x40 [35380.988375] [<ffff0000080b0104>] handle_hva_to_gpa+0xb0/0xec [35380.994016] [<ffff0000080b2644>] kvm_unmap_hva_range+0x5c/0xd0 [35380.999833] [<ffff0000080a8054>] I even injected a fault on purpose in kvm_unmap_hva_range by seting size=size-0x200, the call trace is similar as above. So I thought the panic is similarly caused by the root cause of WARN_ON. Andrea said: : It looks a straightforward safe fix, on x86 hva_to_gfn_memslot would : zap those bits and hide the misalignment caused by the low metadata : bits being erroneously left set in the address, but the arm code : notices when that's the last page in the memslot and the hva_end is : getting aligned and the size is below one page. : : I think the problem triggers in the addr += PAGE_SIZE of : unmap_stage2_ptes that never matches end because end is aligned but : addr is not. : : } while (pte++, addr += PAGE_SIZE, addr != end); : : x86 again only works on hva_start/hva_end after converting it to : gfn_start/end and that being in pfn units the bits are zapped before : they risk to cause trouble. Jia He said: : I've tested by myself in arm64 server (QDF2400,46 cpus,96G mem) Without : this patch, the WARN_ON is very easy for reproducing. After this patch, I : have run the same benchmarch for a whole day without any WARN_ONs Link: http://lkml.kernel.org/r/1525403506-6750-1-git-send-email-hejianet@gmail.com Signed-off-by: Jia He <jia.he(a)hxt-semitech.com> Reviewed-by: Andrea Arcangeli <aarcange(a)redhat.com> Tested-by: Jia He <hejianet(a)gmail.com> Cc: Suzuki K Poulose <Suzuki.Poulose(a)arm.com> Cc: Minchan Kim <minchan(a)kernel.org> Cc: Claudio Imbrenda <imbrenda(a)linux.vnet.ibm.com> Cc: Arvind Yadav <arvind.yadav.cs(a)gmail.com> Cc: Mike Rapoport <rppt(a)linux.vnet.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/ksm.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff -puN mm/ksm.c~mm-ksm-ignore-stable_flag-of-rmap_item-address-in-rmap_walk_ksm mm/ksm.c --- a/mm/ksm.c~mm-ksm-ignore-stable_flag-of-rmap_item-address-in-rmap_walk_ksm +++ a/mm/ksm.c @@ -216,6 +216,8 @@ struct rmap_item { #define SEQNR_MASK 0x0ff /* low bits of unstable tree seqnr */ #define UNSTABLE_FLAG 0x100 /* is a node of the unstable tree */ #define STABLE_FLAG 0x200 /* is listed from the stable tree */ +#define KSM_FLAG_MASK (SEQNR_MASK|UNSTABLE_FLAG|STABLE_FLAG) + /* to mask all the flags */ /* The stable and unstable tree heads */ static struct rb_root one_stable_tree[1] = { RB_ROOT }; @@ -2598,10 +2600,15 @@ again: anon_vma_lock_read(anon_vma); anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, 0, ULONG_MAX) { + unsigned long addr; + cond_resched(); vma = vmac->vma; - if (rmap_item->address < vma->vm_start || - rmap_item->address >= vma->vm_end) + + /* Ignore the stable/unstable/sqnr flags */ + addr = rmap_item->address & ~KSM_FLAG_MASK; + + if (addr < vma->vm_start || addr >= vma->vm_end) continue; /* * Initially we examine only the vma which covers this @@ -2615,8 +2622,7 @@ again: if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) continue; - if (!rwc->rmap_one(page, vma, - rmap_item->address, rwc->arg)) { + if (!rwc->rmap_one(page, vma, addr, rwc->arg)) { anon_vma_unlock_read(anon_vma); return; } _

7 years, 3 months

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[PATCH 1/2] drm/i915: Disallow interlaced modes on g4x DP outputs

by Ville Syrjala

From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Looks like interlaced DP output doesn't work on g4x either. Not all that surprising considering we already established that interlaced DP output is busted on VLV/CHV. Cc: stable(a)vger.kernel.org Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> --- drivers/gpu/drm/i915/intel_dp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 40ffd9163175..6068986fd985 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1869,7 +1869,7 @@ intel_dp_compute_config(struct intel_encoder *encoder, conn_state->scaling_mode); } - if ((IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) && + if (HAS_GMCH_DISPLAY(dev_priv) && adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) return false; @@ -6351,7 +6351,7 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port, drm_connector_init(dev, connector, &intel_dp_connector_funcs, type); drm_connector_helper_add(connector, &intel_dp_connector_helper_funcs); - if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) + if (!HAS_GMCH_DISPLAY(dev_priv)) connector->interlace_allowed = true; connector->doublescan_allowed = 0; -- 2.16.4

7 years, 3 months

3
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[PATCH] powerpc/e500mc: Set assembler machine type to e500mc

by Michael Jeanson

In binutils 2.26 a new opcode for the "wait" instruction was added for the POWER9 and has precedence over the one specific to the e500mc. Commit ebf714ff3756 ("powerpc/e500mc: Add support for the wait instruction in e500_idle") uses this instruction specifically on the e500mc to work around an erratum. This results in an invalid instruction in idle_e500 when we build for the e500mc on bintutils >= 2.26 with the default assembler machine type. Since multiplatform between e500 and non-e500 is not supported, set the assembler machine type globaly when CONFIG_PPC_E500MC=y. Signed-off-by: Michael Jeanson <mjeanson(a)efficios.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> CC: Benjamin Herrenschmidt <benh(a)kernel.crashing.org> CC: Paul Mackerras <paulus(a)samba.org> CC: Michael Ellerman <mpe(a)ellerman.id.au> CC: Kumar Gala <galak(a)kernel.crashing.org> CC: Vakul Garg <vakul.garg(a)nxp.com> CC: Scott Wood <swood(a)redhat.com> CC: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> CC: linuxppc-dev(a)lists.ozlabs.org CC: linux-kernel(a)vger.kernel.org CC: stable(a)vger.kernel.org --- arch/powerpc/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 95813df90801..bb2523b4bd8f 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -251,6 +251,7 @@ cpu-as-$(CONFIG_4xx) += -Wa,-m405 cpu-as-$(CONFIG_ALTIVEC) += $(call as-option,-Wa$(comma)-maltivec) cpu-as-$(CONFIG_E200) += -Wa,-me200 cpu-as-$(CONFIG_PPC_BOOK3S_64) += -Wa,-mpower4 +cpu-as-$(CONFIG_PPC_E500MC) += $(call as-option,-Wa$(comma)-me500mc) KBUILD_AFLAGS += $(cpu-as-y) KBUILD_CFLAGS += $(cpu-as-y) -- 2.17.1

7 years, 3 months

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[B][PATCH v2 1/1] block: do not use interruptible wait anywhere

by Khalid Elmously

From: Alan Jenkins <alan.christopher.jenkins(a)gmail.com> BugLink: http://bugs.launchpad.net/bugs/1776887 When blk_queue_enter() waits for a queue to unfreeze, or unset the PREEMPT_ONLY flag, do not allow it to be interrupted by a signal. The PREEMPT_ONLY flag was introduced later in commit 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably"). Note the SCSI device is resumed asynchronously, i.e. after un-freezing userspace tasks. So that commit exposed the bug as a regression in v4.15. A mysterious SIGBUS (or -EIO) sometimes happened during the time the device was being resumed. Most frequently, there was no kernel log message, and we saw Xorg or Xwayland killed by SIGBUS.[1] [1] E.g. https://bugzilla.redhat.com/show_bug.cgi?id=1553979 Without this fix, I get an IO error in this test: # dd if=/dev/sda of=/dev/null iflag=direct & \ while killall -SIGUSR1 dd; do sleep 0.1; done & \ echo mem > /sys/power/state ; \ sleep 5; killall dd # stop after 5 seconds The interruptible wait was added to blk_queue_enter in commit 3ef28e83ab15 ("block: generic request_queue reference counting"). Before then, the interruptible wait was only in blk-mq, but I don't think it could ever have been correct. Reviewed-by: Bart Van Assche <bart.vanassche(a)wdc.com> Cc: stable(a)vger.kernel.org Signed-off-by: Alan Jenkins <alan.christopher.jenkins(a)gmail.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> (cherry-picked from 1dc3039bc87ae7d19a990c3ee71cfd8a9068f428) Signed-off-by: Khalid Elmously <khalid.elmously(a)canonical.com> --- block/blk-core.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index fc0666354af3..59c91e345eea 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -821,7 +821,6 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) while (true) { bool success = false; - int ret; rcu_read_lock(); if (percpu_ref_tryget_live(&q->q_usage_counter)) { @@ -853,14 +852,12 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) */ smp_rmb(); - ret = wait_event_interruptible(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && - (preempt || !blk_queue_preempt_only(q))) || - blk_queue_dying(q)); + wait_event(q->mq_freeze_wq, + (atomic_read(&q->mq_freeze_depth) == 0 && + (preempt || !blk_queue_preempt_only(q))) || + blk_queue_dying(q)); if (blk_queue_dying(q)) return -ENODEV; - if (ret) - return ret; } } -- 2.17.1

7 years, 3 months

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