November 2024 - Linux-stable-mirror

[PATCH v3] x86/hyper-v: Fix hv tsc page based sched_clock for hibernation

by Naman Jain

read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is bigger than the variable hv_sched_clock_offset, which is cached during early boot, but depending on the timing this assumption may be false when a hibernated VM starts again (the clock counter starts from 0 again) and is resuming back (Note: hv_init_tsc_clocksource() is not called during hibernation/resume); consequently, read_hv_sched_clock_tsc() may return a negative integer (which is interpreted as a huge positive integer since the return type is u64) and new kernel messages are prefixed with huge timestamps before read_hv_sched_clock_tsc() grows big enough (which typically takes several seconds). Fix the issue by saving the Hyper-V clock counter just before the suspend, and using it to correct the hv_sched_clock_offset in resume. This makes hv tsc page based sched_clock continuous and ensures that post resume, it starts from where it left off during suspend. Override x86_platform.save_sched_clock_state and x86_platform.restore_sched_clock_state routines to correct this as soon as possible. Note: if Invariant TSC is available, the issue doesn't happen because 1) we don't register read_hv_sched_clock_tsc() for sched clock: See commit e5313f1c5404 ("clocksource/drivers/hyper-v: Rework clocksource and sched clock setup"); 2) the common x86 code adjusts TSC similarly: see __restore_processor_state() -> tsc_verify_tsc_adjust(true) and x86_platform.restore_sched_clock_state(). Cc: stable(a)vger.kernel.org Fixes: 1349401ff1aa ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation") Co-developed-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Dexuan Cui <decui(a)microsoft.com> Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com> --- Changes from v2: https://lore.kernel.org/all/20240911045632.3757-1-namjain@linux.microsoft.c… Addressed Michael's comments: * Changed commit msg to include information on making timestamps continuous * Changed subject to reflect the new file being changed * Changed variable name for saving offset/counters * Moved comment on new function introduced from header file to function definition. * Removed the equations in comments * Rebased to latest linux-next tip Changes from v1: https://lore.kernel.org/all/20240909053923.8512-1-namjain@linux.microsoft.c… * Reorganized code as per Michael's comment, and moved the logic to x86 specific files, to keep hyperv_timer.c arch independent. --- arch/x86/kernel/cpu/mshyperv.c | 58 ++++++++++++++++++++++++++++++ drivers/clocksource/hyperv_timer.c | 14 +++++++- include/clocksource/hyperv_timer.h | 2 ++ 3 files changed, 73 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index ead967479fa6..e8e25d6e64cd 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -224,6 +224,63 @@ static void hv_machine_crash_shutdown(struct pt_regs *regs) hyperv_cleanup(); } #endif /* CONFIG_CRASH_DUMP */ + +static u64 hv_ref_counter_at_suspend; +static void (*old_save_sched_clock_state)(void); +static void (*old_restore_sched_clock_state)(void); + +/* + * Hyper-V clock counter resets during hibernation. Save and restore clock + * offset during suspend/resume, while also considering the time passed + * before suspend. This is to make sure that sched_clock using hv tsc page + * based clocksource, proceeds from where it left off during suspend and + * it shows correct time for the timestamps of kernel messages after resume. + */ +static void save_hv_clock_tsc_state(void) +{ + hv_ref_counter_at_suspend = hv_read_reference_counter(); +} + +static void restore_hv_clock_tsc_state(void) +{ + /* + * Adjust the offsets used by hv tsc clocksource to + * account for the time spent before hibernation. + * adjusted value = reference counter (time) at suspend + * - reference counter (time) now. + */ + hv_adj_sched_clock_offset(hv_ref_counter_at_suspend - hv_read_reference_counter()); +} + +/* + * Functions to override save_sched_clock_state and restore_sched_clock_state + * functions of x86_platform. The Hyper-V clock counter is reset during + * suspend-resume and the offset used to measure time needs to be + * corrected, post resume. + */ +static void hv_save_sched_clock_state(void) +{ + old_save_sched_clock_state(); + save_hv_clock_tsc_state(); +} + +static void hv_restore_sched_clock_state(void) +{ + restore_hv_clock_tsc_state(); + old_restore_sched_clock_state(); +} + +static void __init x86_setup_ops_for_tsc_pg_clock(void) +{ + if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) + return; + + old_save_sched_clock_state = x86_platform.save_sched_clock_state; + x86_platform.save_sched_clock_state = hv_save_sched_clock_state; + + old_restore_sched_clock_state = x86_platform.restore_sched_clock_state; + x86_platform.restore_sched_clock_state = hv_restore_sched_clock_state; +} #endif /* CONFIG_HYPERV */ static uint32_t __init ms_hyperv_platform(void) @@ -590,6 +647,7 @@ static void __init ms_hyperv_init_platform(void) /* Register Hyper-V specific clocksource */ hv_init_clocksource(); + x86_setup_ops_for_tsc_pg_clock(); hv_vtl_init_platform(); #endif /* diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 99177835cade..b39dee7b93af 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -27,7 +27,8 @@ #include <asm/mshyperv.h> static struct clock_event_device __percpu *hv_clock_event; -static u64 hv_sched_clock_offset __ro_after_init; +/* Note: offset can hold negative values after hibernation. */ +static u64 hv_sched_clock_offset __read_mostly; /* * If false, we're using the old mechanism for stimer0 interrupts @@ -470,6 +471,17 @@ static void resume_hv_clock_tsc(struct clocksource *arg) hv_set_msr(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64); } +/* + * Called during resume from hibernation, from overridden + * x86_platform.restore_sched_clock_state routine. This is to adjust offsets + * used to calculate time for hv tsc page based sched_clock, to account for + * time spent before hibernation. + */ +void hv_adj_sched_clock_offset(u64 offset) +{ + hv_sched_clock_offset -= offset; +} + #ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK static int hv_cs_enable(struct clocksource *cs) { diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index 6cdc873ac907..aa5233b1eba9 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -38,6 +38,8 @@ extern void hv_remap_tsc_clocksource(void); extern unsigned long hv_get_tsc_pfn(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); +extern void hv_adj_sched_clock_offset(u64 offset); + static __always_inline bool hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, u64 *cur_tsc, u64 *time) base-commit: a430d95c5efa2b545d26a094eb5f624e36732af0 -- 2.34.1

9 months, 1 week

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[PATCH] tools: hv: Fix a complier warning in the fcopy uio daemon

by Dexuan Cui

hv_fcopy_uio_daemon.c:436:53: warning: '%s' directive output may be truncated writing up to 14 bytes into a region of size 10 [-Wformat-truncation=] 436 | snprintf(uio_dev_path, sizeof(uio_dev_path), "/dev/%s", uio_name); Also added 'static' for the array 'desc[]'. Fixes: 82b0945ce2c2 ("tools: hv: Add new fcopy application based on uio driver") Cc: stable(a)vger.kernel.org # 6.10+ Signed-off-by: Dexuan Cui <decui(a)microsoft.com> --- tools/hv/hv_fcopy_uio_daemon.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c index 3ce316cc9f97..f7741af08a79 100644 --- a/tools/hv/hv_fcopy_uio_daemon.c +++ b/tools/hv/hv_fcopy_uio_daemon.c @@ -35,8 +35,6 @@ #define WIN8_SRV_MINOR 1 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR) -#define MAX_FOLDER_NAME 15 -#define MAX_PATH_LEN 15 #define FCOPY_UIO "/sys/bus/vmbus/devices/eb765408-105f-49b6-b4aa-c123b64d17d4/uio" #define FCOPY_VER_COUNT 1 @@ -51,7 +49,7 @@ static const int fw_versions[] = { #define HV_RING_SIZE 0x4000 /* 16KB ring buffer size */ -unsigned char desc[HV_RING_SIZE]; +static unsigned char desc[HV_RING_SIZE]; static int target_fd; static char target_fname[PATH_MAX]; @@ -402,8 +400,8 @@ int main(int argc, char *argv[]) struct vmbus_br txbr, rxbr; void *ring; uint32_t len = HV_RING_SIZE; - char uio_name[MAX_FOLDER_NAME] = {0}; - char uio_dev_path[MAX_PATH_LEN] = {0}; + char uio_name[NAME_MAX] = {0}; + char uio_dev_path[PATH_MAX] = {0}; static struct option long_options[] = { {"help", no_argument, 0, 'h' }, -- 2.25.1

9 months, 1 week

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[PATCH 6.6] KVM: x86/mmu: Ensure that kvm_release_pfn_clean() takes exact pfn from kvm_faultin_pfn()

by Nikolay Kuratov

Since 5.16 and prior to 6.13 KVM can't be used with FSDAX guest memory (PMD pages). To reproduce the issue you need to reserve guest memory with `memmap=` cmdline, create and mount FS in DAX mode (tested both XFS and ext4), see doc link below. ndctl command for test: ndctl create-namespace -v -e namespace1.0 --map=dev --mode=fsdax -a 2M Then pass memory object to qemu like: -m 8G -object memory-backend-file,id=ram0,size=8G,\ mem-path=/mnt/pmem/guestmem,share=on,prealloc=on,dump=off,align=2097152 \ -numa node,memdev=ram0,cpus=0-1 QEMU fails to run guest with error: kvm run failed Bad address and there are two warnings in dmesg: WARN_ON_ONCE(!page_count(page)) in kvm_is_zone_device_page() and WARN_ON_ONCE(folio_ref_count(folio) <= 0) in try_grab_folio() (v6.6.63) It looks like in the past assumption was made that pfn won't change from faultin_pfn() to release_pfn_clean(), e.g. see commit 4cd071d13c5c ("KVM: x86/mmu: Move calls to thp_adjust() down a level") But kvm_page_fault structure made pfn part of mutable state, so now release_pfn_clean() can take hugepage-adjusted pfn. And it works for all cases (/dev/shm, hugetlb, devdax) except fsdax. Apparently in fsdax mode faultin-pfn and adjusted-pfn may refer to different folios, so we're getting get_page/put_page imbalance. To solve this preserve faultin pfn in separate kvm_page_fault field and pass it in kvm_release_pfn_clean(). Patch tested for all mentioned guest memory backends with tdp_mmu={0,1}. No bug in upstream as it was solved fundamentally by commit 8dd861cc07e2 ("KVM: x86/mmu: Put refcounted pages instead of blindly releasing pfns") and related patch series. Link: https://nvdimm.docs.kernel.org/2mib_fs_dax.html Fixes: 2f6305dd5676 ("KVM: MMU: change kvm_tdp_mmu_map() arguments to kvm_page_fault") Signed-off-by: Nikolay Kuratov <kniv(a)yandex-team.ru> --- arch/x86/kvm/mmu/mmu.c | 5 +++-- arch/x86/kvm/mmu/mmu_internal.h | 2 ++ arch/x86/kvm/mmu/paging_tmpl.h | 2 +- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 294775b7383b..2105f3bc2e59 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4321,6 +4321,7 @@ static int kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault, smp_rmb(); ret = __kvm_faultin_pfn(vcpu, fault); + fault->faultin_pfn = fault->pfn; if (ret != RET_PF_CONTINUE) return ret; @@ -4398,7 +4399,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault out_unlock: write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_clean(fault->faultin_pfn); return r; } @@ -4474,7 +4475,7 @@ static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, out_unlock: read_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_clean(fault->faultin_pfn); return r; } #endif diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index decc1f153669..a016b51f9c62 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -236,6 +236,8 @@ struct kvm_page_fault { /* Outputs of kvm_faultin_pfn. */ unsigned long mmu_seq; kvm_pfn_t pfn; + /* pfn copy for kvm_release_pfn_clean(), constant after kvm_faultin_pfn() */ + kvm_pfn_t faultin_pfn; hva_t hva; bool map_writable; diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index c85255073f67..b945dde6e3be 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -848,7 +848,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault out_unlock: write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_clean(fault->faultin_pfn); return r; } -- 2.34.1

9 months, 1 week

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[PATCH net v2 0/5] Make TCP-MD5-diag slightly less broken

by Dmitry Safonov via B4 Relay

Changes in v2: - Fixup for uninitilized md5sig_count stack variable (Oops! Kudos to kernel test robot <lkp(a)intel.com>) - Correct space damage, add a missing Fixes tag & reformat tcp_ulp_ops_size() (Kuniyuki Iwashima) - Take out patch for maximum attribute length, see (4) below. Going to send it later with the next TCP-AO-diag part (Kuniyuki Iwashima) - Link to v1: https://lore.kernel.org/r/20241106-tcp-md5-diag-prep-v1-0-d62debf3dded@gmai… My original intent was to replace the last non-upstream Arista's TCP-AO piece. That is per-netns procfs seqfile which lists AO keys. In my view an acceptable upstream alternative would be TCP-AO-diag uAPI. So, I started by looking and reviewing TCP-MD5-diag code. And straight away I saw a bunch of issues: 1. Similarly to TCP_MD5SIG_EXT, which doesn't check tcpm_flags for unknown flags and so being non-extendable setsockopt(), the same way tcp_diag_put_md5sig() dumps md5 keys in an array of tcp_diag_md5sig, which makes it ABI non-extendable structure as userspace can't tolerate any new members in it. 2. Inet-diag allocates netlink message for sockets in inet_diag_dump_one_icsk(), which uses a TCP-diag callback .idiag_get_aux_size(), that pre-calculates the needed space for TCP-diag related information. But as neither socket lock nor rcu_readlock() are held between allocation and the actual TCP info filling, the TCP-related space requirement may change before reaching tcp_diag_put_md5sig(). I.e., the number of TCP-MD5 keys on a socket. Thankfully, TCP-MD5-diag won't overwrite the skb, but will return EMSGSIZE, triggering WARN_ON() in inet_diag_dump_one_icsk(). 3. Inet-diag "do" request* can create skb of any message required size. But "dump" request* the skb size, since d35c99ff77ec ("netlink: do not enter direct reclaim from netlink_dump()") is limited by 32 KB. Having in mind that sizeof(struct tcp_diag_md5sig) = 100 bytes, dumps for sockets that have more than 327 keys are going to fail (not counting other diag infos, which lower this limit futher). That is much lower than the number of TCP-MD5 keys that can be allocated on a socket with the current default optmem_max limit (128Kb). So, then I went and written selftests for TCP-MD5-diag and besides confirming that (2) and (3) are not theoretical issues, I also discovered another issues, that I didn't notice on code inspection: 4. nlattr::nla_len is __u16, which limits the largest netlink attibute by 64Kb or by 655 tcp_diag_md5sig keys in the diag array. What happens de-facto is that the netlink attribute gets u16 overflow, breaking the userspace parsing - RTA_NEXT(), that should point to the next attribute, points into the middle of md5 keys array. In this patch set issues (2) and (4) are addressed. (2) by not returning EMSGSIZE when the dump raced with modifying TCP-MD5 keys on a socket, but mark the dump inconsistent by setting NLM_F_DUMP_INTR nlmsg flag. Which changes uAPI in situations where previously kernel did WARN() and errored the dump. (4) by artificially limiting the maximum attribute size by U16_MAX - 1. In order to remove the new limit from (4) solution, my plan is to convert the dump of TCP-MD5 keys from an array to NL_ATTR_TYPE_NESTED_ARRAY (or alike), which should also address (1). And for (3), it's needed to teach tcp-diag how-to remember not only socket on which previous recvmsg() stopped, but potentially TCP-MD5 key as well. I plan in the next part of patch set address (3), (1) and the new limit for (4), together with adding new TCP-AO-diag. * Terminology from Documentation/userspace-api/netlink/intro.rst Signed-off-by: Dmitry Safonov <0x7f454c46(a)gmail.com> --- Dmitry Safonov (5): net/diag: Do not race on dumping MD5 keys with adding new MD5 keys net/diag: Warn only once on EMSGSIZE net/diag: Pre-allocate optional info only if requested net/diag: Always pre-allocate tcp_ulp info net/netlink: Correct the comment on netlink message max cap include/linux/inet_diag.h | 3 +- include/net/tcp.h | 1 - net/ipv4/inet_diag.c | 89 ++++++++++++++++++++++++++++++++++++++--------- net/ipv4/tcp_diag.c | 68 ++++++++++++++++++------------------ net/mptcp/diag.c | 20 ----------- net/netlink/af_netlink.c | 4 +-- net/tls/tls_main.c | 17 --------- 7 files changed, 110 insertions(+), 92 deletions(-) --- base-commit: f1b785f4c7870c42330b35522c2514e39a1e28e7 change-id: 20241106-tcp-md5-diag-prep-2f0dcf371d90 Best regards, -- Dmitry Safonov <0x7f454c46(a)gmail.com>

9 months, 1 week

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[PATCH] fs/ceph/file: fix memory leaks in __ceph_sync_read()

by Max Kellermann

In two `break` statements, the call to ceph_release_page_vector() was missing, leaking the allocation from ceph_alloc_page_vector(). Cc: stable(a)vger.kernel.org Signed-off-by: Max Kellermann <max.kellermann(a)ionos.com> --- fs/ceph/file.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 4b8d59ebda00..24d0f1cc9aac 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1134,6 +1134,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, extent_cnt = __ceph_sparse_read_ext_count(inode, read_len); ret = ceph_alloc_sparse_ext_map(op, extent_cnt); if (ret) { + ceph_release_page_vector(pages, num_pages); ceph_osdc_put_request(req); break; } @@ -1168,6 +1169,7 @@ ssize_t __ceph_sync_read(struct inode *inode, loff_t *ki_pos, op->extent.sparse_ext_cnt); if (fret < 0) { ret = fret; + ceph_release_page_vector(pages, num_pages); ceph_osdc_put_request(req); break; } -- 2.45.2

9 months, 1 week

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[PATCH 6.6.x] btrfs: add cancellation points to trim loops

by David Sterba

From: Luca Stefani <luca.stefani.ge1(a)gmail.com> There are reports that system cannot suspend due to running trim because the task responsible for trimming the device isn't able to finish in time, especially since we have a free extent discarding phase, which can trim a lot of unallocated space. There are no limits on the trim size (unlike the block group part). Since trime isn't a critical call it can be interrupted at any time, in such cases we stop the trim, report the amount of discarded bytes and return an error. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219180 Link: https://bugzilla.suse.com/show_bug.cgi?id=1229737 CC: stable(a)vger.kernel.org # 5.15+ Signed-off-by: Luca Stefani <luca.stefani.ge1(a)gmail.com> Reviewed-by: David Sterba <dsterba(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> --- fs/btrfs/extent-tree.c | 7 ++++++- fs/btrfs/free-space-cache.c | 4 ++-- fs/btrfs/free-space-cache.h | 7 +++++++ 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b3680e1c7054..599407120513 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -1319,6 +1319,11 @@ static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, start += bytes_to_discard; bytes_left -= bytes_to_discard; *discarded_bytes += bytes_to_discard; + + if (btrfs_trim_interrupted()) { + ret = -ERESTARTSYS; + break; + } } return ret; @@ -6094,7 +6099,7 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) start += len; *trimmed += bytes; - if (fatal_signal_pending(current)) { + if (btrfs_trim_interrupted()) { ret = -ERESTARTSYS; break; } diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 3bcf4a30cad7..9a6ec9344c3e 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -3808,7 +3808,7 @@ static int trim_no_bitmap(struct btrfs_block_group *block_group, if (async && *total_trimmed) break; - if (fatal_signal_pending(current)) { + if (btrfs_trim_interrupted()) { ret = -ERESTARTSYS; break; } @@ -3999,7 +3999,7 @@ static int trim_bitmaps(struct btrfs_block_group *block_group, } block_group->discard_cursor = start; - if (fatal_signal_pending(current)) { + if (btrfs_trim_interrupted()) { if (start != offset) reset_trimming_bitmap(ctl, offset); ret = -ERESTARTSYS; diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h index 33b4da3271b1..bd80c7b2af96 100644 --- a/fs/btrfs/free-space-cache.h +++ b/fs/btrfs/free-space-cache.h @@ -6,6 +6,8 @@ #ifndef BTRFS_FREE_SPACE_CACHE_H #define BTRFS_FREE_SPACE_CACHE_H +#include <linux/freezer.h> + /* * This is the trim state of an extent or bitmap. * @@ -43,6 +45,11 @@ static inline bool btrfs_free_space_trimming_bitmap( return (info->trim_state == BTRFS_TRIM_STATE_TRIMMING); } +static inline bool btrfs_trim_interrupted(void) +{ + return fatal_signal_pending(current) || freezing(current); +} + /* * Deltas are an effective way to populate global statistics. Give macro names * to make it clear what we're doing. An example is discard_extents in -- 2.45.0

9 months, 1 week

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please revert backport of 44c76825d6eefee9eb7ce06c38e1a6632ac7eb7d

by Kees Cook

Hi stable tree maintainers, Please revert the backports of 44c76825d6ee ("x86: Increase brk randomness entropy for 64-bit systems") namely: 5.4: 03475167fda50b8511ef620a27409b08365882e1 5.10: 25d31baf922c1ee987efd6fcc9c7d4ab539c66b4 5.15: 06cb3463aa58906cfff72877eb7f50cb26e9ca93 6.1: b0cde867b80a5e81fcbc0383e138f5845f2005ee 6.6: 1a45994fb218d93dec48a3a86f68283db61e0936 There seems to be a bad interaction between this change and older PIE-built qemu-user-static (for aarch64) binaries[1]. Investigation continues to see if this will need to be reverted from 6.6, 6.11, and mainline. But for now, it's clearly a problem for older kernels with older qemu. Thanks! -Kees [1] https://lore.kernel.org/all/202411201000.F3313C02@keescook/ -- Kees Cook

9 months, 1 week

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[PATCH v2 0/2] drm/msm/dpu: two fixes targeting 6.11

by Dmitry Baryshkov

Leonard Lausen reported an issue with suspend/resume of the sc7180 devices. Fix the WB atomic check, which caused the issue. Also make sure that DPU debugging logs are always directed to the drm_debug / DRIVER so that usual drm.debug masks work in an expected way. Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> --- Changes in v2: - Reworked the writeback to just drop the connector->status check. - Expanded commit message for the debugging patch. - Link to v1: https://lore.kernel.org/r/20240709-dpu-fix-wb-v1-0-448348bfd4cb@linaro.org --- Dmitry Baryshkov (2): drm/msm/dpu1: don't choke on disabling the writeback connector drm/msm/dpu: don't play tricks with debug macros drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h | 14 ++------------ drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 3 --- 2 files changed, 2 insertions(+), 15 deletions(-) --- base-commit: 668d33c9ff922c4590c58754ab064aaf53c387dd change-id: 20240709-dpu-fix-wb-6cd57e3eb182 Best regards, -- Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org>

9 months, 1 week

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[PATCH v2] mm: Respect mmap hint address when aligning for THP

by Kalesh Singh

Commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") updated __get_unmapped_area() to align the start address for the VMA to a PMD boundary if CONFIG_TRANSPARENT_HUGEPAGE=y. It does this by effectively looking up a region that is of size, request_size + PMD_SIZE, and aligning up the start to a PMD boundary. Commit 4ef9ad19e176 ("mm: huge_memory: don't force huge page alignment on 32 bit") opted out of this for 32bit due to regressions in mmap base randomization. Commit d4148aeab412 ("mm, mmap: limit THP alignment of anonymous mappings to PMD-aligned sizes") restricted this to only mmap sizes that are multiples of the PMD_SIZE due to reported regressions in some performance benchmarks -- which seemed mostly due to the reduced spatial locality of related mappings due to the forced PMD-alignment. Another unintended side effect has emerged: When a user specifies an mmap hint address, the THP alignment logic modifies the behavior, potentially ignoring the hint even if a sufficiently large gap exists at the requested hint location. Example Scenario: Consider the following simplified virtual address (VA) space: ... 0x200000-0x400000 --- VMA A 0x400000-0x600000 --- Hole 0x600000-0x800000 --- VMA B ... A call to mmap() with hint=0x400000 and len=0x200000 behaves differently: - Before THP alignment: The requested region (size 0x200000) fits into the gap at 0x400000, so the hint is respected. - After alignment: The logic searches for a region of size 0x400000 (len + PMD_SIZE) starting at 0x400000. This search fails due to the mapping at 0x600000 (VMA B), and the hint is ignored, falling back to arch_get_unmapped_area[_topdown](). In general the hint is effectively ignored, if there is any existing mapping in the below range: [mmap_hint + mmap_size, mmap_hint + mmap_size + PMD_SIZE) This changes the semantics of mmap hint; from ""Respect the hint if a sufficiently large gap exists at the requested location" to "Respect the hint only if an additional PMD-sized gap exists beyond the requested size". This has performance implications for allocators that allocate their heap using mmap but try to keep it "as contiguous as possible" by using the end of the exisiting heap as the address hint. With the new behavior it's more likely to get a much less contiguous heap, adding extra fragmentation and performance overhead. To restore the expected behavior; don't use thp_get_unmapped_area_vmflags() when the user provided a hint address, for anonymous mappings. Note: As, Yang Shi, pointed out: the issue still remains for filesystems which are using thp_get_unmapped_area() for their get_unmapped_area() op. It is unclear what worklaods will regress for if we ignore THP alignment when the hint address is provided for such file backed mappings -- so this fix will be handled separately. Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Yang Shi <yang(a)os.amperecomputing.com> Cc: Rik van Riel <riel(a)surriel.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Minchan Kim <minchan(a)kernel.org> Cc: Hans Boehm <hboehm(a)google.com> Cc: Lokesh Gidra <lokeshgidra(a)google.com> Cc: <stable(a)vger.kernel.org> Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") Signed-off-by: Kalesh Singh <kaleshsingh(a)google.com> Reviewed-by: Rik van Riel <riel(a)surriel.com> Reviewed-by: Vlastimil Babka <vbabka(a)suse.cz> --- Changes in v2: - Clarify the handling of file backed mappings, as highlighted by Yang - Collect Vlastimil's and Rik's Reviewed-by's mm/mmap.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mmap.c b/mm/mmap.c index 79d541f1502b..2f01f1a8e304 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -901,6 +901,7 @@ __get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, if (get_area) { addr = get_area(file, addr, len, pgoff, flags); } else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) + && !addr /* no hint */ && IS_ALIGNED(len, PMD_SIZE)) { /* Ensures that larger anonymous mappings are THP aligned. */ addr = thp_get_unmapped_area_vmflags(file, addr, len, base-commit: 2d5404caa8c7bb5c4e0435f94b28834ae5456623 -- 2.47.0.338.g60cca15819-goog

9 months, 1 week

4
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[PATCH v2] ARM: dts: dra7: Add bus_dma_limit for l4 cfg bus

by Romain Naour

From: Romain Naour <romain.naour(a)skf.com> A bus_dma_limit was added for l3 bus by commit cfb5d65f2595 ("ARM: dts: dra7: Add bus_dma_limit for L3 bus") to fix an issue observed only with SATA on DRA7-EVM with 4GB RAM and CONFIG_ARM_LPAE enabled. Since kernel 5.13, the SATA issue can be reproduced again following the SATA node move from L3 bus to L4_cfg in commit 8af15365a368 ("ARM: dts: Configure interconnect target module for dra7 sata"). Fix it by adding an empty dma-ranges property to l4_cfg and segment@100000 nodes (parent device tree node of SATA controller) to inherit the 2GB dma ranges limit from l3 bus node. Note: A similar fix was applied for PCIe controller by commit 90d4d3f4ea45 ("ARM: dts: dra7: Fix bus_dma_limit for PCIe"). Fixes: 8af15365a368 ("ARM: dts: Configure interconnect target module for dra7 sata"). Link: https://lore.kernel.org/linux-omap/c583e1bb-f56b-4489-8012-ce742e85f233@smi… Cc: <stable(a)vger.kernel.org> # 5.13 Signed-off-by: Romain Naour <romain.naour(a)skf.com> --- v2: add stable tag --- arch/arm/boot/dts/ti/omap/dra7-l4.dtsi | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi index 6e67d99832ac..ba7fdaae9c6e 100644 --- a/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi +++ b/arch/arm/boot/dts/ti/omap/dra7-l4.dtsi @@ -12,6 +12,7 @@ &l4_cfg { /* 0x4a000000 */ ranges = <0x00000000 0x4a000000 0x100000>, /* segment 0 */ <0x00100000 0x4a100000 0x100000>, /* segment 1 */ <0x00200000 0x4a200000 0x100000>; /* segment 2 */ + dma-ranges; segment@0 { /* 0x4a000000 */ compatible = "simple-pm-bus"; @@ -557,6 +558,7 @@ segment@100000 { /* 0x4a100000 */ <0x0007e000 0x0017e000 0x001000>, /* ap 124 */ <0x00059000 0x00159000 0x001000>, /* ap 125 */ <0x0005a000 0x0015a000 0x001000>; /* ap 126 */ + dma-ranges; target-module@2000 { /* 0x4a102000, ap 27 3c.0 */ compatible = "ti,sysc"; -- 2.45.0

9 months, 1 week

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Linux-stable-mirror November 2024