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[PATCH 1/1] iommu/vt-d: Enable ATS before cache tag assignment

by Lu Baolu

Commit <4f1492efb495> ("iommu/vt-d: Revert ATS timing change to fix boot failure") placed the enabling of ATS in the probe_finalize callback. This occurs after the default domain attachment, which is when the ATS cache tag is assigned. Consequently, the device TLB cache tag is missed when the domain is attached, leading to the device TLB not being invalidated in the iommu_unmap paths. Fix it by moving the ATS enabling to the default domain attachment path, ensuring ATS is enabled before the cache tag assignment. Fixes: 4f1492efb495 ("iommu/vt-d: Revert ATS timing change to fix boot failure") Cc: stable(a)vger.kernel.org Signed-off-by: Lu Baolu <baolu.lu(a)linux.intel.com> --- drivers/iommu/intel/iommu.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 7aa3932251b2..863ccb47bcca 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -54,6 +54,7 @@ __DOMAIN_MAX_PFN(gaw), (unsigned long)-1)) #define DOMAIN_MAX_ADDR(gaw) (((uint64_t)__DOMAIN_MAX_PFN(gaw)) << VTD_PAGE_SHIFT) +static void sm_iommu_enable_pcicaps(struct device *dev); static void __init check_tylersburg_isoch(void); static int rwbf_quirk; @@ -1825,10 +1826,11 @@ static int dmar_domain_attach_device(struct dmar_domain *domain, else ret = domain_setup_second_level(iommu, domain, dev, IOMMU_NO_PASID, NULL); - if (ret) goto out_block_translation; + /* PCI ATS enablement must happen before cache tag assigning. */ + sm_iommu_enable_pcicaps(dev); ret = cache_tag_assign_domain(domain, dev, IOMMU_NO_PASID); if (ret) goto out_block_translation; @@ -3765,11 +3767,18 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) return ERR_PTR(ret); } -static void intel_iommu_probe_finalize(struct device *dev) +static void sm_iommu_enable_pcicaps(struct device *dev) { struct device_domain_info *info = dev_iommu_priv_get(dev); struct intel_iommu *iommu = info->iommu; + /* + * Called only in iommu_device_register() path when iommu is + * configured in the scalable mode. + */ + if (!sm_supported(iommu) || READ_ONCE(iommu->iommu.ready)) + return; + /* * The PCIe spec, in its wisdom, declares that the behaviour of the * device is undefined if you enable PASID support after ATS support. @@ -3780,7 +3789,7 @@ static void intel_iommu_probe_finalize(struct device *dev) !pci_enable_pasid(to_pci_dev(dev), info->pasid_supported & ~1)) info->pasid_enabled = 1; - if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) + if (!dev_is_real_dma_subdevice(dev)) iommu_enable_pci_ats(info); iommu_enable_pci_pri(info); } @@ -4309,6 +4318,7 @@ static int identity_domain_attach_dev(struct iommu_domain *domain, struct device ret = intel_pasid_setup_pass_through(iommu, dev, IOMMU_NO_PASID); else ret = device_setup_pass_through(dev); + sm_iommu_enable_pcicaps(dev); if (!ret) info->domain_attached = true; @@ -4359,7 +4369,6 @@ const struct iommu_ops intel_iommu_ops = { .domain_alloc_sva = intel_svm_domain_alloc, .domain_alloc_nested = intel_iommu_domain_alloc_nested, .probe_device = intel_iommu_probe_device, - .probe_finalize = intel_iommu_probe_finalize, .release_device = intel_iommu_release_device, .get_resv_regions = intel_iommu_get_resv_regions, .device_group = intel_iommu_device_group, -- 2.43.0

5 days, 23 hours

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[regression v6.12.30..v6.12.32] mmc1: mmc_select_hs400 failed, error -110 / boot regression on Lenovo IdeaPad 1 15ADA7

by Salvatore Bonaccorso

Hi In Debian we got a regression report booting on a Lenovo IdeaPad 1 15ADA7 dropping finally into the initramfs shell after updating from 6.12.30 to 6.12.32 with messages before dropping into the intiramfs shell: mmc1: mmc_select_hs400 failed, error -110 mmc1: error -110 whilst initialising MMC card The original report is at https://bugs.debian.org/1107979 and the reporter tested as well kernel up to 6.15.3 which still fails to boot. Another similar report landed with after the same version update as https://bugs.debian.org/1107979 . I only see three commits touching drivers/mmc between 6.12.30..6.12.32: 28306c58daf8 ("mmc: sdhci: Disable SD card clock before changing parameters") 38828e0dc771 ("mmc: dw_mmc: add exynos7870 DW MMC support") 67bb2175095e ("mmc: host: Wait for Vdd to settle on card power off") I have found a potential similar issue reported in ArchLinux at https://bbs.archlinux.org/viewtopic.php?id=306024 I have asked if we can get more information out of the boot, but maybe this regression report already rings bell for you? #regzbot introduced v6.12.30..v6.12.32 #regzbot link: https://bugs.debian.org/1107979 #regzbot link: https://bbs.archlinux.org/viewtopic.php?id=306024 Regards, Salvatore

6 days

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[PATCH v3 4/4] wifi: ath12k: fix dest ring-buffer corruption when ring is full

by Johan Hovold

Add the missing memory barriers to make sure that destination ring descriptors are read before updating the tail pointer (and passing ownership to the device) to avoid memory corruption on weakly ordered architectures like aarch64 when the ring is full. Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Cc: stable(a)vger.kernel.org # 6.3 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/net/wireless/ath/ath12k/hal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c index d8193d9577bb..6406fcf5d69f 100644 --- a/drivers/net/wireless/ath/ath12k/hal.c +++ b/drivers/net/wireless/ath/ath12k/hal.c @@ -2170,7 +2170,6 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) { lockdep_assert_held(&srng->lock); - /* TODO: See if we need a write memory barrier here */ if (srng->flags & HAL_SRNG_FLAGS_LMAC_RING) { /* For LMAC rings, ring pointer updates are done through FW and * hence written to a shared memory location that is read by FW @@ -2185,7 +2184,11 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) WRITE_ONCE(*srng->u.src_ring.hp_addr, srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; - *srng->u.dst_ring.tp_addr = srng->u.dst_ring.tp; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + dma_mb(); + WRITE_ONCE(*srng->u.dst_ring.tp_addr, srng->u.dst_ring.tp); } } else { if (srng->ring_dir == HAL_SRNG_DIR_SRC) { @@ -2201,6 +2204,10 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + mb(); ath12k_hif_write32(ab, (unsigned long)srng->u.dst_ring.tp_addr - (unsigned long)ab->mem, -- 2.49.0

6 days, 2 hours

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[PATCH v3 3/4] wifi: ath12k: fix source ring-buffer corruption

by Johan Hovold

Add the missing memory barrier to make sure that LMAC source ring descriptors are written before updating the head pointer to avoid passing stale data to the firmware on weakly ordered architectures like aarch64. Note that non-LMAC rings use MMIO write accessors which have the required write memory barrier. Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Cc: stable(a)vger.kernel.org # 6.3 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/net/wireless/ath/ath12k/hal.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c index 726969cfcaec..d8193d9577bb 100644 --- a/drivers/net/wireless/ath/ath12k/hal.c +++ b/drivers/net/wireless/ath/ath12k/hal.c @@ -2178,7 +2178,11 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) if (srng->ring_dir == HAL_SRNG_DIR_SRC) { srng->u.src_ring.last_tp = *(volatile u32 *)srng->u.src_ring.tp_addr; - *srng->u.src_ring.hp_addr = srng->u.src_ring.hp; + /* Make sure descriptor is written before updating the + * head pointer. + */ + dma_wmb(); + WRITE_ONCE(*srng->u.src_ring.hp_addr, srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; *srng->u.dst_ring.tp_addr = srng->u.dst_ring.tp; @@ -2187,6 +2191,10 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) if (srng->ring_dir == HAL_SRNG_DIR_SRC) { srng->u.src_ring.last_tp = *(volatile u32 *)srng->u.src_ring.tp_addr; + /* Assume implementation use an MMIO write accessor + * which has the required wmb() so that the descriptor + * is written before the updating the head pointer. + */ ath12k_hif_write32(ab, (unsigned long)srng->u.src_ring.hp_addr - (unsigned long)ab->mem, -- 2.49.0

6 days, 2 hours

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[PATCH v3 1/4] wifi: ath12k: fix dest ring-buffer corruption

by Johan Hovold

Add the missing memory barrier to make sure that destination ring descriptors are read after the head pointers to avoid using stale data on weakly ordered architectures like aarch64. The barrier is added to the ath12k_hal_srng_access_begin() helper for symmetry with follow-on fixes for source ring buffer corruption which will add barriers to ath12k_hal_srng_access_end(). Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Cc: stable(a)vger.kernel.org # 6.3 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/net/wireless/ath/ath12k/ce.c | 3 --- drivers/net/wireless/ath/ath12k/hal.c | 17 ++++++++++++++--- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/ce.c b/drivers/net/wireless/ath/ath12k/ce.c index 3f3439262cf4..f7c15b547504 100644 --- a/drivers/net/wireless/ath/ath12k/ce.c +++ b/drivers/net/wireless/ath/ath12k/ce.c @@ -433,9 +433,6 @@ static int ath12k_ce_completed_recv_next(struct ath12k_ce_pipe *pipe, goto err; } - /* Make sure descriptor is read after the head pointer. */ - dma_rmb(); - *nbytes = ath12k_hal_ce_dst_status_get_length(desc); *skb = pipe->dest_ring->skb[sw_index]; diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c index a301898e5849..f8bd3837b9dc 100644 --- a/drivers/net/wireless/ath/ath12k/hal.c +++ b/drivers/net/wireless/ath/ath12k/hal.c @@ -2143,13 +2143,24 @@ void *ath12k_hal_srng_src_get_next_reaped(struct ath12k_base *ab, void ath12k_hal_srng_access_begin(struct ath12k_base *ab, struct hal_srng *srng) { + u32 hp; + lockdep_assert_held(&srng->lock); - if (srng->ring_dir == HAL_SRNG_DIR_SRC) + if (srng->ring_dir == HAL_SRNG_DIR_SRC) { srng->u.src_ring.cached_tp = *(volatile u32 *)srng->u.src_ring.tp_addr; - else - srng->u.dst_ring.cached_hp = READ_ONCE(*srng->u.dst_ring.hp_addr); + } else { + hp = READ_ONCE(*srng->u.dst_ring.hp_addr); + + if (hp != srng->u.dst_ring.cached_hp) { + srng->u.dst_ring.cached_hp = hp; + /* Make sure descriptor is read after the head + * pointer. + */ + dma_rmb(); + } + } } /* Update cached ring head/tail pointers to HW. ath12k_hal_srng_access_begin() -- 2.49.0

6 days, 2 hours

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+ lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3 has been added to the -mm mm-hotfixes-unstable branch. Its filename is lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Harry Yoo <harry.yoo(a)oracle.com> Subject: lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3 Date: Tue, 24 Jun 2025 16:25:13 +0900 Link: https://lkml.kernel.org/r/20250624072513.84219-1-harry.yoo@oracle.com Reported-by: kernel test robot <oliver.sang(a)intel.com> Closes: https://lore.kernel.org/oe-lkp/202506181351.bba867dd-lkp@intel.com Closes: https://lore.kernel.org/oe-lkp/202506131711.5b41931c-lkp@intel.com Fixes: 780138b12381 ("alloc_tag: check mem_profiling_support in alloc_tag_init") Fixes: 1438d349d16b ("lib: add memory allocations report in show_mem()") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> Cc: Casey Chen <cachen(a)purestorage.com> Cc: David Wang <00107082(a)163.com> Cc: Kent Overstreet <kent.overstreet(a)linux.dev> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Yuanyuan Zhong <yzhong(a)purestorage.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/alloc_tag.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/lib/alloc_tag.c~lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3 +++ a/lib/alloc_tag.c @@ -137,7 +137,8 @@ size_t alloc_tag_top_users(struct codeta if (IS_ERR_OR_NULL(alloc_tag_cttype)) return 0; - else if (can_sleep) + + if (can_sleep) codetag_lock_module_list(alloc_tag_cttype, true); else if (!codetag_trylock_module_list(alloc_tag_cttype)) return 0; _ Patches currently in -mm which might be from harry.yoo(a)oracle.com are lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users.patch lib-alloc_tag-do-not-acquire-non-existent-lock-in-alloc_tag_top_users-v3.patch

6 days, 4 hours

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[stable 6.12+] x86/pkeys: Simplify PKRU update in signal frame

by Ben Hutchings

Hi stable maintainers, Please apply commit d1e420772cd1 ("x86/pkeys: Simplify PKRU update in signal frame") to the stable branches for 6.12 and later. This fixes a regression introduced in 6.13 by commit ae6012d72fa6 ("x86/pkeys: Ensure updated PKRU value is XRSTOR'd"), which was also backported in 6.12.5. Ben. -- Ben Hutchings 73.46% of all statistics are made up.

6 days, 6 hours

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[PATCH] x86/fpu: Delay instruction pointer fixup until after after warning

by Dave Hansen

From: Dave Hansen <dave.hansen(a)linux.intel.com> Right now, if XRSTOR fails a console message like this is be printed: Bad FPU state detected at restore_fpregs_from_fpstate+0x9a/0x170, reinitializing FPU registers. However, the text location (...+0x9a in this case) is the instruction *AFTER* the XRSTOR. The highlighted instruction in the "Code:" dump also points one instruction late. The reason is that the "fixup" moves RIP up to pass the bad XRSTOR and keep on running after returning from the #GP handler. But it does this fixup before warning. The resulting warning output is nonsensical because it looks like e non-FPU-related instruction is #GP'ing. Do not fix up RIP until after printing the warning. Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Fixes: d5c8028b4788 ("x86/fpu: Reinitialize FPU registers if restoring FPU state fails") Cc: stable(a)vger.kernel.org Cc: Eric Biggers <ebiggers(a)google.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Chang S. Bae <chang.seok.bae(a)intel.com> --- b/arch/x86/mm/extable.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN arch/x86/mm/extable.c~fixup-fpu-gp-ip-later arch/x86/mm/extable.c --- a/arch/x86/mm/extable.c~fixup-fpu-gp-ip-later 2025-06-18 12:21:30.231719499 -0700 +++ b/arch/x86/mm/extable.c 2025-06-18 12:25:53.979954060 -0700 @@ -122,11 +122,11 @@ static bool ex_handler_sgx(const struct static bool ex_handler_fprestore(const struct exception_table_entry *fixup, struct pt_regs *regs) { - regs->ip = ex_fixup_addr(fixup); - WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs)); + regs->ip = ex_fixup_addr(fixup); + fpu_reset_from_exception_fixup(); return true; } _

6 days, 7 hours

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[tip: x86/urgent] x86/traps: Initialize DR6 by writing its architectural reset value

by tip-bot2 for Xin Li (Intel)

The following commit has been merged into the x86/urgent branch of tip: Commit-ID: 5f465c148c61e876b6d6eacd8e8e365f2d47758f Gitweb: https://git.kernel.org/tip/5f465c148c61e876b6d6eacd8e8e365f2d47758f Author: Xin Li (Intel) <xin(a)zytor.com> AuthorDate: Fri, 20 Jun 2025 16:15:03 -07:00 Committer: Dave Hansen <dave.hansen(a)linux.intel.com> CommitterDate: Tue, 24 Jun 2025 13:15:51 -07:00 x86/traps: Initialize DR6 by writing its architectural reset value Initialize DR6 by writing its architectural reset value to avoid incorrectly zeroing DR6 to clear DR6.BLD at boot time, which leads to a false bus lock detected warning. The Intel SDM says: 1) Certain debug exceptions may clear bits 0-3 of DR6. 2) BLD induced #DB clears DR6.BLD and any other debug exception doesn't modify DR6.BLD. 3) RTM induced #DB clears DR6.RTM and any other debug exception sets DR6.RTM. To avoid confusion in identifying debug exceptions, debug handlers should set DR6.BLD and DR6.RTM, and clear other DR6 bits before returning. The DR6 architectural reset value 0xFFFF0FF0, already defined as macro DR6_RESERVED, satisfies these requirements, so just use it to reinitialize DR6 whenever needed. Since clear_all_debug_regs() no longer zeros all debug registers, rename it to initialize_debug_regs() to better reflect its current behavior. Since debug_read_clear_dr6() no longer clears DR6, rename it to debug_read_reset_dr6() to better reflect its current behavior. Fixes: ebb1064e7c2e9 ("x86/traps: Handle #DB for bus lock") Reported-by: Sohil Mehta <sohil.mehta(a)intel.com> Suggested-by: H. Peter Anvin (Intel) <hpa(a)zytor.com> Signed-off-by: Xin Li (Intel) <xin(a)zytor.com> Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Reviewed-by: H. Peter Anvin (Intel) <hpa(a)zytor.com> Reviewed-by: Sohil Mehta <sohil.mehta(a)intel.com> Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Tested-by: Sohil Mehta <sohil.mehta(a)intel.com> Link: https://lore.kernel.org/lkml/06e68373-a92b-472e-8fd9-ba548119770c@intel.com/ Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250620231504.2676902-2-xin%40zytor.com --- arch/x86/include/uapi/asm/debugreg.h | 21 ++++++++++++++++- arch/x86/kernel/cpu/common.c | 24 +++++++------------ arch/x86/kernel/traps.c | 34 ++++++++++++++++----------- 3 files changed, 51 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/uapi/asm/debugreg.h b/arch/x86/include/uapi/asm/debugreg.h index 0007ba0..41da492 100644 --- a/arch/x86/include/uapi/asm/debugreg.h +++ b/arch/x86/include/uapi/asm/debugreg.h @@ -15,7 +15,26 @@ which debugging register was responsible for the trap. The other bits are either reserved or not of interest to us. */ -/* Define reserved bits in DR6 which are always set to 1 */ +/* + * Define bits in DR6 which are set to 1 by default. + * + * This is also the DR6 architectural value following Power-up, Reset or INIT. + * + * Note, with the introduction of Bus Lock Detection (BLD) and Restricted + * Transactional Memory (RTM), the DR6 register has been modified: + * + * 1) BLD flag (bit 11) is no longer reserved to 1 if the CPU supports + * Bus Lock Detection. The assertion of a bus lock could clear it. + * + * 2) RTM flag (bit 16) is no longer reserved to 1 if the CPU supports + * restricted transactional memory. #DB occurred inside an RTM region + * could clear it. + * + * Apparently, DR6.BLD and DR6.RTM are active low bits. + * + * As a result, DR6_RESERVED is an incorrect name now, but it is kept for + * compatibility. + */ #define DR6_RESERVED (0xFFFF0FF0) #define DR_TRAP0 (0x1) /* db0 */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8feb8fd..0f6c280 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2243,20 +2243,16 @@ EXPORT_PER_CPU_SYMBOL(__stack_chk_guard); #endif #endif -/* - * Clear all 6 debug registers: - */ -static void clear_all_debug_regs(void) +static void initialize_debug_regs(void) { - int i; - - for (i = 0; i < 8; i++) { - /* Ignore db4, db5 */ - if ((i == 4) || (i == 5)) - continue; - - set_debugreg(0, i); - } + /* Control register first -- to make sure everything is disabled. */ + set_debugreg(0, 7); + set_debugreg(DR6_RESERVED, 6); + /* dr5 and dr4 don't exist */ + set_debugreg(0, 3); + set_debugreg(0, 2); + set_debugreg(0, 1); + set_debugreg(0, 0); } #ifdef CONFIG_KGDB @@ -2417,7 +2413,7 @@ void cpu_init(void) load_mm_ldt(&init_mm); - clear_all_debug_regs(); + initialize_debug_regs(); dbg_restore_debug_regs(); doublefault_init_cpu_tss(); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c5c897a..36354b4 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1022,24 +1022,32 @@ static bool is_sysenter_singlestep(struct pt_regs *regs) #endif } -static __always_inline unsigned long debug_read_clear_dr6(void) +static __always_inline unsigned long debug_read_reset_dr6(void) { unsigned long dr6; + get_debugreg(dr6, 6); + dr6 ^= DR6_RESERVED; /* Flip to positive polarity */ + /* * The Intel SDM says: * - * Certain debug exceptions may clear bits 0-3. The remaining - * contents of the DR6 register are never cleared by the - * processor. To avoid confusion in identifying debug - * exceptions, debug handlers should clear the register before - * returning to the interrupted task. + * Certain debug exceptions may clear bits 0-3 of DR6. + * + * BLD induced #DB clears DR6.BLD and any other debug + * exception doesn't modify DR6.BLD. * - * Keep it simple: clear DR6 immediately. + * RTM induced #DB clears DR6.RTM and any other debug + * exception sets DR6.RTM. + * + * To avoid confusion in identifying debug exceptions, + * debug handlers should set DR6.BLD and DR6.RTM, and + * clear other DR6 bits before returning. + * + * Keep it simple: write DR6 with its architectural reset + * value 0xFFFF0FF0, defined as DR6_RESERVED, immediately. */ - get_debugreg(dr6, 6); set_debugreg(DR6_RESERVED, 6); - dr6 ^= DR6_RESERVED; /* Flip to positive polarity */ return dr6; } @@ -1239,13 +1247,13 @@ out: /* IST stack entry */ DEFINE_IDTENTRY_DEBUG(exc_debug) { - exc_debug_kernel(regs, debug_read_clear_dr6()); + exc_debug_kernel(regs, debug_read_reset_dr6()); } /* User entry, runs on regular task stack */ DEFINE_IDTENTRY_DEBUG_USER(exc_debug) { - exc_debug_user(regs, debug_read_clear_dr6()); + exc_debug_user(regs, debug_read_reset_dr6()); } #ifdef CONFIG_X86_FRED @@ -1264,7 +1272,7 @@ DEFINE_FREDENTRY_DEBUG(exc_debug) { /* * FRED #DB stores DR6 on the stack in the format which - * debug_read_clear_dr6() returns for the IDT entry points. + * debug_read_reset_dr6() returns for the IDT entry points. */ unsigned long dr6 = fred_event_data(regs); @@ -1279,7 +1287,7 @@ DEFINE_FREDENTRY_DEBUG(exc_debug) /* 32 bit does not have separate entry points. */ DEFINE_IDTENTRY_RAW(exc_debug) { - unsigned long dr6 = debug_read_clear_dr6(); + unsigned long dr6 = debug_read_reset_dr6(); if (user_mode(regs)) exc_debug_user(regs, dr6);

6 days, 7 hours

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+ maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: maple_tree: fix mt_destroy_walk() on root leaf node has been added to the -mm mm-hotfixes-unstable branch. Its filename is maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Wei Yang <richard.weiyang(a)gmail.com> Subject: maple_tree: fix mt_destroy_walk() on root leaf node Date: Tue, 24 Jun 2025 15:18:40 -0400 On destroy, we should set each node dead. But current code miss this when the maple tree has only the root node. The reason is mt_destroy_walk() leverage mte_destroy_descend() to set node dead, but this is skipped since the only root node is a leaf. Fixes this by setting the node dead if it is a leaf. Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.co… Link: https://lkml.kernel.org/r/20250624191841.64682-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Wei Yang <richard.weiyang(a)gmail.com> Signed-off-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/maple_tree.c | 1 + 1 file changed, 1 insertion(+) --- a/lib/maple_tree.c~maple_tree-fix-mt_destroy_walk-on-root-leaf-node +++ a/lib/maple_tree.c @@ -5319,6 +5319,7 @@ static void mt_destroy_walk(struct maple struct maple_enode *start; if (mte_is_leaf(enode)) { + mte_set_node_dead(enode); node->type = mte_node_type(enode); goto free_leaf; } _ Patches currently in -mm which might be from richard.weiyang(a)gmail.com are maple_tree-fix-mt_destroy_walk-on-root-leaf-node.patch maple_tree-assert-retrieving-new-value-on-a-tree-containing-just-a-leaf-node.patch

6 days, 8 hours

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