June 2024 - Linux-stable-mirror

[PATCH 1/4] ata: libata-core: Fix null pointer dereference on error

by Niklas Cassel

If the ata_port_alloc() call in ata_host_alloc() fails, ata_host_release() will get called. However, the code in ata_host_release() tries to free ata_port struct members unconditionally, which can lead to the following: BUG: unable to handle page fault for address: 0000000000003990 PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 PID: 594 Comm: (udev-worker) Not tainted 6.10.0-rc5 #44 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:ata_host_release.cold+0x2f/0x6e [libata] Code: e4 4d 63 f4 44 89 e2 48 c7 c6 90 ad 32 c0 48 c7 c7 d0 70 33 c0 49 83 c6 0e 41 RSP: 0018:ffffc90000ebb968 EFLAGS: 00010246 RAX: 0000000000000041 RBX: ffff88810fb52e78 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88813b3218c0 RDI: ffff88813b3218c0 RBP: ffff88810fb52e40 R08: 0000000000000000 R09: 6c65725f74736f68 R10: ffffc90000ebb738 R11: 73692033203a746e R12: 0000000000000004 R13: 0000000000000000 R14: 0000000000000011 R15: 0000000000000006 FS: 00007f6cc55b9980(0000) GS:ffff88813b300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000003990 CR3: 00000001122a2000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15a/0x2f0 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? ata_host_release.cold+0x2f/0x6e [libata] ? ata_host_release.cold+0x2f/0x6e [libata] release_nodes+0x35/0xb0 devres_release_group+0x113/0x140 ata_host_alloc+0xed/0x120 [libata] ata_host_alloc_pinfo+0x14/0xa0 [libata] ahci_init_one+0x6c9/0xd20 [ahci] Do not access ata_port struct members unconditionally. Fixes: 633273a3ed1c ("libata-pmp: hook PMP support and enable it") Cc: stable(a)vger.kernel.org Reviewed-by: Damien Le Moal <dlemoal(a)kernel.org> Reviewed-by: Hannes Reinecke <hare(a)suse.de> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/ata/libata-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index e1bf8a19b3c8..f47838da75d7 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5518,6 +5518,9 @@ static void ata_host_release(struct kref *kref) for (i = 0; i < host->n_ports; i++) { struct ata_port *ap = host->ports[i]; + if (!ap) + continue; + kfree(ap->pmp_link); kfree(ap->slave_link); kfree(ap->ncq_sense_buf); -- 2.45.2

2 months, 4 weeks

2
1
0 0

[git:media_stage/master] media: venus: fix use after free in vdec_close

by Hans Verkuil

This is an automatic generated email to let you know that the following patch were queued: Subject: media: venus: fix use after free in vdec_close Author: Dikshita Agarwal <quic_dikshita(a)quicinc.com> Date: Thu May 9 10:44:29 2024 +0530 There appears to be a possible use after free with vdec_close(). The firmware will add buffer release work to the work queue through HFI callbacks as a normal part of decoding. Randomly closing the decoder device from userspace during normal decoding can incur a read after free for inst. Fix it by cancelling the work in vdec_close. Cc: stable(a)vger.kernel.org Fixes: af2c3834c8ca ("[media] media: venus: adding core part and helper functions") Signed-off-by: Dikshita Agarwal <quic_dikshita(a)quicinc.com> Acked-by: Vikash Garodia <quic_vgarodia(a)quicinc.com> Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov(a)gmail.com> Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl> drivers/media/platform/qcom/venus/vdec.c | 1 + 1 file changed, 1 insertion(+) --- diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c index 0d2ab95bec0f..d12089370d91 100644 --- a/drivers/media/platform/qcom/venus/vdec.c +++ b/drivers/media/platform/qcom/venus/vdec.c @@ -1747,6 +1747,7 @@ static int vdec_close(struct file *file) vdec_pm_get(inst); + cancel_work_sync(&inst->delayed_process_work); v4l2_m2m_ctx_release(inst->m2m_ctx); v4l2_m2m_release(inst->m2m_dev); vdec_ctrl_deinit(inst);

2 months, 4 weeks

1
0
0 0

[PATCH v2 1/2] arm64: dts: mediatek: mt7622: readd syscon to pciesys node

by Christian Marangi

Sata node reference the pciesys with the property mediatek,phy-node and that is used as a syscon to access the pciesys regs. Readd the syscon compatible to pciesys node to restore correct functionality of the SATA interface. Fixes: 3ba5a6159434 ("arm64: dts: mediatek: mt7622: fix clock controllers") Reported-by: Frank Wunderlich <frank-w(a)public-files.de> Co-developed-by: Frank Wunderlich <frank-w(a)public-files.de> Signed-off-by: Frank Wunderlich <frank-w(a)public-files.de> Signed-off-by: Christian Marangi <ansuelsmth(a)gmail.com> Cc: stable(a)vger.kernel.org --- arch/arm64/boot/dts/mediatek/mt7622.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/mediatek/mt7622.dtsi b/arch/arm64/boot/dts/mediatek/mt7622.dtsi index 917fa39a74f8..bb0ec1edbe5b 100644 --- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi +++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi @@ -790,7 +790,7 @@ u2port1: usb-phy@1a0c5000 { }; pciesys: clock-controller@1a100800 { - compatible = "mediatek,mt7622-pciesys"; + compatible = "mediatek,mt7622-pciesys", "syscon"; reg = <0 0x1a100800 0 0x1000>; #clock-cells = <1>; #reset-cells = <1>; -- 2.45.1

3 months

3
2
0 0

Re: Fw:Re: clasps ,clips , buckles ,leather hardware ,bag hardware ,shoe hardware ,cord hardware ,hockey hardware, head pins ,wallets ,trims ,handles,tools ,fashion supply ?

by bestfactory＠126.vip.com

Dear Sir : Nice day! This is Su from METAL & HARNESSES factory ,we make D rings , O rings ,Plastic hardware ,clasps ,clips , buckles ,leather hardware ,bag hardware ,shoe hardware ,cord hardware ,hockey hardware, head pins ,wallets ,trims ,handles,tools ,fashion ,wires ,fastening,rivets , grommets,eyelets,buckles,screws , harnesses ,wires ,bolts ,nuts ,clips ,bits ,spurs ,screws,anchors,stainless steel hardware , brass hardware,steel harnesses ,aluminium hardware ,iron hardware ,metal & Harnesses,belt and buckles,straps ,leather Harnesses,tags ,belts,straps ,clips ,rings bars ,hooks , safety buckles,brass buckles, brass rings ,belts,buckles ,Split Ring ,straps ,sliders,snaps ,Bars Rings, Fasteners, magnent buttons,craft hardware ,bindings ,knobs,steps ,straps , bits ,eyelets ,tools , metal gear , metal hardware , metal products, metal Components,S hooks ,bars ,snaps ,webbings , buckles, HOOK,brass buckles, clips , hooks ,straps , accessories ,brass snaps ,brass gear , stainless steel hardware,steel harness ,steel wires, wire rings , wire buckles ,brass gears ,brass products ,iron metal hardware ,Fasteners,safety buckles,brass buckles, brass rings ,belts,buckles ,Ring ,Squares ,straps ,sliders,Bars Rings,Buckles, Cord locks, Hooks & Rings,Tabs, Locks and Slides,magnent buttons,carabiners,trigger ,buttons ,snaps ,fasteners, webbings , webbing buckles, buttons,Hook Loop ，textile accessories,safety buckles,sliders,snaps ,Rings ,chains,suspenders as required for our global clients . We are manufactory, we are the source, our price is very competitive ,you will get the best price , We have profuse designs with series quality grade, and expressly. Our factory always produce customer designs and drawing , if you have any products looking please let me know we could surely make for you Sincerely hope could work with you ! Best regards Su

3 months

1
0
0 0

FAILED: patch "[PATCH] efi/x86: Free EFI memory map only when installing a new one." failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 75dde792d6f6c2d0af50278bd374bf0c512fe196 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024062448-overspend-lucid-de35@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 75dde792d6f6 ("efi/x86: Free EFI memory map only when installing a new one.") d85e3e349407 ("efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures") fdc6d38d64a2 ("efi: memmap: Move manipulation routines into x86 arch tree") 1df4d1724baa ("drivers: fix typo in firmware/efi/memmap.c") db01ea882bf6 ("efi: Correct comment on efi_memmap_alloc") 3ecc68349bba ("memblock: rename memblock_free to memblock_phys_free") fa27717110ae ("memblock: drop memblock_free_early_nid() and memblock_free_early()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 75dde792d6f6c2d0af50278bd374bf0c512fe196 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel <ardb(a)kernel.org> Date: Mon, 10 Jun 2024 16:02:13 +0200 Subject: [PATCH] efi/x86: Free EFI memory map only when installing a new one. The logic in __efi_memmap_init() is shared between two different execution flows: - mapping the EFI memory map early or late into the kernel VA space, so that its entries can be accessed; - the x86 specific cloning of the EFI memory map in order to insert new entries that are created as a result of making a memory reservation via a call to efi_mem_reserve(). In the former case, the underlying memory containing the kernel's view of the EFI memory map (which may be heavily modified by the kernel itself on x86) is not modified at all, and the only thing that changes is the virtual mapping of this memory, which is different between early and late boot. In the latter case, an entirely new allocation is created that carries a new, updated version of the kernel's view of the EFI memory map. When installing this new version, the old version will no longer be referenced, and if the memory was allocated by the kernel, it will leak unless it gets freed. The logic that implements this freeing currently lives on the code path that is shared between these two use cases, but it should only apply to the latter. So move it to the correct spot. While at it, drop the dummy definition for non-x86 architectures, as that is no longer needed. Cc: <stable(a)vger.kernel.org> Fixes: f0ef6523475f ("efi: Fix efi_memmap_alloc() leaks") Tested-by: Ashish Kalra <Ashish.Kalra(a)amd.com> Link: https://lore.kernel.org/all/36ad5079-4326-45ed-85f6-928ff76483d3@amd.com Signed-off-by: Ard Biesheuvel <ardb(a)kernel.org> diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 1dc600fa3ba5..481096177500 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -401,7 +401,6 @@ extern int __init efi_memmap_alloc(unsigned int num_entries, struct efi_memory_map_data *data); extern void __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags); -#define __efi_memmap_free __efi_memmap_free extern int __init efi_memmap_install(struct efi_memory_map_data *data); extern int __init efi_memmap_split_count(efi_memory_desc_t *md, diff --git a/arch/x86/platform/efi/memmap.c b/arch/x86/platform/efi/memmap.c index 4ef20b49eb5e..6ed1935504b9 100644 --- a/arch/x86/platform/efi/memmap.c +++ b/arch/x86/platform/efi/memmap.c @@ -92,12 +92,22 @@ int __init efi_memmap_alloc(unsigned int num_entries, */ int __init efi_memmap_install(struct efi_memory_map_data *data) { + unsigned long size = efi.memmap.desc_size * efi.memmap.nr_map; + unsigned long flags = efi.memmap.flags; + u64 phys = efi.memmap.phys_map; + int ret; + efi_memmap_unmap(); if (efi_enabled(EFI_PARAVIRT)) return 0; - return __efi_memmap_init(data); + ret = __efi_memmap_init(data); + if (ret) + return ret; + + __efi_memmap_free(phys, size, flags); + return 0; } /** diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index 3365944f7965..34109fd86c55 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -15,10 +15,6 @@ #include <asm/early_ioremap.h> #include <asm/efi.h> -#ifndef __efi_memmap_free -#define __efi_memmap_free(phys, size, flags) do { } while (0) -#endif - /** * __efi_memmap_init - Common code for mapping the EFI memory map * @data: EFI memory map data @@ -51,11 +47,6 @@ int __init __efi_memmap_init(struct efi_memory_map_data *data) return -ENOMEM; } - if (efi.memmap.flags & (EFI_MEMMAP_MEMBLOCK | EFI_MEMMAP_SLAB)) - __efi_memmap_free(efi.memmap.phys_map, - efi.memmap.desc_size * efi.memmap.nr_map, - efi.memmap.flags); - map.phys_map = data->phys_map; map.nr_map = data->size / data->desc_size; map.map_end = map.map + data->size;

3 months

2
5
0 0

[PATCH 4/4] ata: ahci: Clean up sysfs file on error

by Niklas Cassel

.probe() (ahci_init_one()) calls sysfs_add_file_to_group(), however, if probe() fails after this call, we currently never call sysfs_remove_file_from_group(). (The sysfs_remove_file_from_group() call in .remove() (ahci_remove_one()) does not help, as .remove() is not called on .probe() error.) Thus, if probe() fails after the sysfs_add_file_to_group() call, the next time we insmod the module we will get: sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:04.0/remapped_nvme' CPU: 11 PID: 954 Comm: modprobe Not tainted 6.10.0-rc5 #43 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 sysfs_warn_dup.cold+0x17/0x23 sysfs_add_file_mode_ns+0x11a/0x130 sysfs_add_file_to_group+0x7e/0xc0 ahci_init_one+0x31f/0xd40 [ahci] Fixes: 894fba7f434a ("ata: ahci: Add sysfs attribute to show remapped NVMe device count") Cc: stable(a)vger.kernel.org Reviewed-by: Damien Le Moal <dlemoal(a)kernel.org> Reviewed-by: Hannes Reinecke <hare(a)suse.de> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/ata/ahci.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 5eb38fbbbecd..fc6fd583faf8 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1975,8 +1975,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map)); host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports); - if (!host) - return -ENOMEM; + if (!host) { + rc = -ENOMEM; + goto err_rm_sysfs_file; + } host->private_data = hpriv; if (ahci_init_msi(pdev, n_ports, hpriv) < 0) { @@ -2031,11 +2033,11 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) /* initialize adapter */ rc = ahci_configure_dma_masks(pdev, hpriv); if (rc) - return rc; + goto err_rm_sysfs_file; rc = ahci_pci_reset_controller(host); if (rc) - return rc; + goto err_rm_sysfs_file; ahci_pci_init_controller(host); ahci_pci_print_info(host); @@ -2044,10 +2046,15 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) rc = ahci_host_activate(host, &ahci_sht); if (rc) - return rc; + goto err_rm_sysfs_file; pm_runtime_put_noidle(&pdev->dev); return 0; + +err_rm_sysfs_file: + sysfs_remove_file_from_group(&pdev->dev.kobj, + &dev_attr_remapped_nvme.attr, NULL); + return rc; } static void ahci_shutdown_one(struct pci_dev *pdev) -- 2.45.2

3 months

1
0
0 0

[PATCH 3/4] ata: libata-core: Fix double free on error

by Niklas Cassel

If e.g. the ata_port_alloc() call in ata_host_alloc() fails, we will jump to the err_out label, which will call devres_release_group(). devres_release_group() will trigger a call to ata_host_release(). ata_host_release() calls kfree(host), so executing the kfree(host) in ata_host_alloc() will lead to a double free: kernel BUG at mm/slub.c:553! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 11 PID: 599 Comm: (udev-worker) Not tainted 6.10.0-rc5 #47 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:kfree+0x2cf/0x2f0 Code: 5d 41 5e 41 5f 5d e9 80 d6 ff ff 4d 89 f1 41 b8 01 00 00 00 48 89 d9 48 89 da RSP: 0018:ffffc90000f377f0 EFLAGS: 00010246 RAX: ffff888112b1f2c0 RBX: ffff888112b1f2c0 RCX: ffff888112b1f320 RDX: 000000000000400b RSI: ffffffffc02c9de5 RDI: ffff888112b1f2c0 RBP: ffffc90000f37830 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000f37610 R11: 617461203a736b6e R12: ffffea00044ac780 R13: ffff888100046400 R14: ffffffffc02c9de5 R15: 0000000000000006 FS: 00007f2f1cabe980(0000) GS:ffff88813b380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f1c3acf75 CR3: 0000000111724000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x6a/0x90 ? kfree+0x2cf/0x2f0 ? exc_invalid_op+0x50/0x70 ? kfree+0x2cf/0x2f0 ? asm_exc_invalid_op+0x1a/0x20 ? ata_host_alloc+0xf5/0x120 [libata] ? ata_host_alloc+0xf5/0x120 [libata] ? kfree+0x2cf/0x2f0 ata_host_alloc+0xf5/0x120 [libata] ata_host_alloc_pinfo+0x14/0xa0 [libata] ahci_init_one+0x6c9/0xd20 [ahci] Ensure that we will not call kfree(host) twice, by performing the kfree() only if the devres_open_group() call failed. Fixes: dafd6c496381 ("libata: ensure host is free'd on error exit paths") Cc: stable(a)vger.kernel.org Reviewed-by: Damien Le Moal <dlemoal(a)kernel.org> Reviewed-by: Hannes Reinecke <hare(a)suse.de> Signed-off-by: Niklas Cassel <cassel(a)kernel.org> --- drivers/ata/libata-core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 481baa55ebfc..e0455a182af7 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5578,8 +5578,10 @@ struct ata_host *ata_host_alloc(struct device *dev, int max_ports) if (!host) return NULL; - if (!devres_open_group(dev, NULL, GFP_KERNEL)) - goto err_free; + if (!devres_open_group(dev, NULL, GFP_KERNEL)) { + kfree(host); + return NULL; + } dr = devres_alloc(ata_devres_release, 0, GFP_KERNEL); if (!dr) @@ -5611,8 +5613,6 @@ struct ata_host *ata_host_alloc(struct device *dev, int max_ports) err_out: devres_release_group(dev, NULL); - err_free: - kfree(host); return NULL; } EXPORT_SYMBOL_GPL(ata_host_alloc); -- 2.45.2

3 months

1
0
0 0

[v3 linus-tree PATCH] mm: gup: stop abusing try_grab_folio

by Yang Shi

A kernel warning was reported when pinning folio in CMA memory when launching SEV virtual machine. The splat looks like: [ 464.325306] WARNING: CPU: 13 PID: 6734 at mm/gup.c:1313 __get_user_pages+0x423/0x520 [ 464.325464] CPU: 13 PID: 6734 Comm: qemu-kvm Kdump: loaded Not tainted 6.6.33+ #6 [ 464.325477] RIP: 0010:__get_user_pages+0x423/0x520 [ 464.325515] Call Trace: [ 464.325520] <TASK> [ 464.325523] ? __get_user_pages+0x423/0x520 [ 464.325528] ? __warn+0x81/0x130 [ 464.325536] ? __get_user_pages+0x423/0x520 [ 464.325541] ? report_bug+0x171/0x1a0 [ 464.325549] ? handle_bug+0x3c/0x70 [ 464.325554] ? exc_invalid_op+0x17/0x70 [ 464.325558] ? asm_exc_invalid_op+0x1a/0x20 [ 464.325567] ? __get_user_pages+0x423/0x520 [ 464.325575] __gup_longterm_locked+0x212/0x7a0 [ 464.325583] internal_get_user_pages_fast+0xfb/0x190 [ 464.325590] pin_user_pages_fast+0x47/0x60 [ 464.325598] sev_pin_memory+0xca/0x170 [kvm_amd] [ 464.325616] sev_mem_enc_register_region+0x81/0x130 [kvm_amd] Per the analysis done by yangge, when starting the SEV virtual machine, it will call pin_user_pages_fast(..., FOLL_LONGTERM, ...) to pin the memory. But the page is in CMA area, so fast GUP will fail then fallback to the slow path due to the longterm pinnalbe check in try_grab_folio(). The slow path will try to pin the pages then migrate them out of CMA area. But the slow path also uses try_grab_folio() to pin the page, it will also fail due to the same check then the above warning is triggered. In addition, the try_grab_folio() is supposed to be used in fast path and it elevates folio refcount by using add ref unless zero. We are guaranteed to have at least one stable reference in slow path, so the simple atomic add could be used. The performance difference should be trivial, but the misuse may be confusing and misleading. Redefined try_grab_folio() to try_grab_folio_fast(), and try_grab_page() to try_grab_folio(), and use them in the proper paths. This solves both the abuse and the kernel warning. The proper naming makes their usecase more clear and should prevent from abusing in the future. [1] https://lore.kernel.org/linux-mm/1719478388-31917-1-git-send-email-yangge11… Fixes: 57edfcfd3419 ("mm/gup: accelerate thp gup even for "pages != NULL"") Cc: <stable(a)vger.kernel.org> [6.6+] Reported-by: yangge <yangge1116(a)126.com> Signed-off-by: Yang Shi <yang(a)os.amperecomputing.com> --- mm/gup.c | 287 +++++++++++++++++++++++++---------------------- mm/huge_memory.c | 2 +- mm/internal.h | 4 +- 3 files changed, 155 insertions(+), 138 deletions(-) v3: 1. Renamed the patch subject to make it more clear per Peter 2. Rephrased the commit log and elaborated the function renaming per Peter 3. Fixed the comment from Christoph Hellwig v2: 1. Fixed the build warning 2. Reworked the commit log to include the bug report and analysis (reworded by me) from yangge 3. Rebased onto the latest Linus's tree diff --git a/mm/gup.c b/mm/gup.c index ca0f5cedce9b..e65773ce4622 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -97,95 +97,6 @@ static inline struct folio *try_get_folio(struct page *page, int refs) return folio; } -/** - * try_grab_folio() - Attempt to get or pin a folio. - * @page: pointer to page to be grabbed - * @refs: the value to (effectively) add to the folio's refcount - * @flags: gup flags: these are the FOLL_* flag values. - * - * "grab" names in this file mean, "look at flags to decide whether to use - * FOLL_PIN or FOLL_GET behavior, when incrementing the folio's refcount. - * - * Either FOLL_PIN or FOLL_GET (or neither) must be set, but not both at the - * same time. (That's true throughout the get_user_pages*() and - * pin_user_pages*() APIs.) Cases: - * - * FOLL_GET: folio's refcount will be incremented by @refs. - * - * FOLL_PIN on large folios: folio's refcount will be incremented by - * @refs, and its pincount will be incremented by @refs. - * - * FOLL_PIN on single-page folios: folio's refcount will be incremented by - * @refs * GUP_PIN_COUNTING_BIAS. - * - * Return: The folio containing @page (with refcount appropriately - * incremented) for success, or NULL upon failure. If neither FOLL_GET - * nor FOLL_PIN was set, that's considered failure, and furthermore, - * a likely bug in the caller, so a warning is also emitted. - */ -struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags) -{ - struct folio *folio; - - if (WARN_ON_ONCE((flags & (FOLL_GET | FOLL_PIN)) == 0)) - return NULL; - - if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page))) - return NULL; - - if (flags & FOLL_GET) - return try_get_folio(page, refs); - - /* FOLL_PIN is set */ - - /* - * Don't take a pin on the zero page - it's not going anywhere - * and it is used in a *lot* of places. - */ - if (is_zero_page(page)) - return page_folio(page); - - folio = try_get_folio(page, refs); - if (!folio) - return NULL; - - /* - * Can't do FOLL_LONGTERM + FOLL_PIN gup fast path if not in a - * right zone, so fail and let the caller fall back to the slow - * path. - */ - if (unlikely((flags & FOLL_LONGTERM) && - !folio_is_longterm_pinnable(folio))) { - if (!put_devmap_managed_folio_refs(folio, refs)) - folio_put_refs(folio, refs); - return NULL; - } - - /* - * When pinning a large folio, use an exact count to track it. - * - * However, be sure to *also* increment the normal folio - * refcount field at least once, so that the folio really - * is pinned. That's why the refcount from the earlier - * try_get_folio() is left intact. - */ - if (folio_test_large(folio)) - atomic_add(refs, &folio->_pincount); - else - folio_ref_add(folio, - refs * (GUP_PIN_COUNTING_BIAS - 1)); - /* - * Adjust the pincount before re-checking the PTE for changes. - * This is essentially a smp_mb() and is paired with a memory - * barrier in folio_try_share_anon_rmap_*(). - */ - smp_mb__after_atomic(); - - node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, refs); - - return folio; -} - static void gup_put_folio(struct folio *folio, int refs, unsigned int flags) { if (flags & FOLL_PIN) { @@ -203,58 +114,59 @@ static void gup_put_folio(struct folio *folio, int refs, unsigned int flags) } /** - * try_grab_page() - elevate a page's refcount by a flag-dependent amount - * @page: pointer to page to be grabbed - * @flags: gup flags: these are the FOLL_* flag values. + * try_grab_folio() - add a folio's refcount by a flag-dependent amount + * @folio: pointer to folio to be grabbed + * @refs: the value to (effectively) add to the folio's refcount + * @flags: gup flags: these are the FOLL_* flag values * * This might not do anything at all, depending on the flags argument. * * "grab" names in this file mean, "look at flags to decide whether to use - * FOLL_PIN or FOLL_GET behavior, when incrementing the page's refcount. + * FOLL_PIN or FOLL_GET behavior, when incrementing the folio's refcount. * * Either FOLL_PIN or FOLL_GET (or neither) may be set, but not both at the same - * time. Cases: please see the try_grab_folio() documentation, with - * "refs=1". + * time. * * Return: 0 for success, or if no action was required (if neither FOLL_PIN * nor FOLL_GET was set, nothing is done). A negative error code for failure: * - * -ENOMEM FOLL_GET or FOLL_PIN was set, but the page could not + * -ENOMEM FOLL_GET or FOLL_PIN was set, but the folio could not * be grabbed. + * + * It is called when we have a stable reference for the folio, typically in + * GUP slow path. */ -int __must_check try_grab_page(struct page *page, unsigned int flags) +int __must_check try_grab_folio(struct folio *folio, int refs, + unsigned int flags) { - struct folio *folio = page_folio(page); - if (WARN_ON_ONCE(folio_ref_count(folio) <= 0)) return -ENOMEM; - if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page))) + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(&folio->page))) return -EREMOTEIO; if (flags & FOLL_GET) - folio_ref_inc(folio); + folio_ref_add(folio, refs); else if (flags & FOLL_PIN) { /* * Don't take a pin on the zero page - it's not going anywhere * and it is used in a *lot* of places. */ - if (is_zero_page(page)) + if (is_zero_folio(folio)) return 0; /* - * Similar to try_grab_folio(): be sure to *also* - * increment the normal page refcount field at least once, + * Increment the normal page refcount field at least once, * so that the page really is pinned. */ if (folio_test_large(folio)) { - folio_ref_add(folio, 1); - atomic_add(1, &folio->_pincount); + folio_ref_add(folio, refs); + atomic_add(refs, &folio->_pincount); } else { - folio_ref_add(folio, GUP_PIN_COUNTING_BIAS); + folio_ref_add(folio, refs * GUP_PIN_COUNTING_BIAS); } - node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, 1); + node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, refs); } return 0; @@ -535,7 +447,7 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end, */ static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz, unsigned long addr, unsigned long end, unsigned int flags, - struct page **pages, int *nr) + struct page **pages, int *nr, bool fast) { unsigned long pte_end; struct page *page; @@ -558,9 +470,15 @@ static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz page = pte_page(pte); refs = record_subpages(page, sz, addr, end, pages + *nr); - folio = try_grab_folio(page, refs, flags); - if (!folio) - return 0; + if (fast) { + folio = try_grab_folio_fast(page, refs, flags); + if (!folio) + return 0; + } else { + folio = page_folio(page); + if (try_grab_folio(folio, refs, flags)) + return 0; + } if (unlikely(pte_val(pte) != pte_val(ptep_get(ptep)))) { gup_put_folio(folio, refs, flags); @@ -588,7 +506,7 @@ static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz static int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd, unsigned long addr, unsigned int pdshift, unsigned long end, unsigned int flags, - struct page **pages, int *nr) + struct page **pages, int *nr, bool fast) { pte_t *ptep; unsigned long sz = 1UL << hugepd_shift(hugepd); @@ -598,7 +516,8 @@ static int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd, ptep = hugepte_offset(hugepd, addr, pdshift); do { next = hugepte_addr_end(addr, end, sz); - ret = gup_hugepte(vma, ptep, sz, addr, end, flags, pages, nr); + ret = gup_hugepte(vma, ptep, sz, addr, end, flags, pages, nr, + fast); if (ret != 1) return ret; } while (ptep++, addr = next, addr != end); @@ -625,7 +544,7 @@ static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd, ptep = hugepte_offset(hugepd, addr, pdshift); ptl = huge_pte_lock(h, vma->vm_mm, ptep); ret = gup_hugepd(vma, hugepd, addr, pdshift, addr + PAGE_SIZE, - flags, &page, &nr); + flags, &page, &nr, false); spin_unlock(ptl); if (ret == 1) { @@ -642,7 +561,7 @@ static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd, static inline int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd, unsigned long addr, unsigned int pdshift, unsigned long end, unsigned int flags, - struct page **pages, int *nr) + struct page **pages, int *nr, bool fast) { return 0; } @@ -729,7 +648,7 @@ static struct page *follow_huge_pud(struct vm_area_struct *vma, gup_must_unshare(vma, flags, page)) return ERR_PTR(-EMLINK); - ret = try_grab_page(page, flags); + ret = try_grab_folio(page_folio(page), 1, flags); if (ret) page = ERR_PTR(ret); else @@ -806,7 +725,7 @@ static struct page *follow_huge_pmd(struct vm_area_struct *vma, VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && !PageAnonExclusive(page), page); - ret = try_grab_page(page, flags); + ret = try_grab_folio(page_folio(page), 1, flags); if (ret) return ERR_PTR(ret); @@ -968,8 +887,8 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && !PageAnonExclusive(page), page); - /* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */ - ret = try_grab_page(page, flags); + /* try_grab_folio() does nothing unless FOLL_GET or FOLL_PIN is set. */ + ret = try_grab_folio(page_folio(page), 1, flags); if (unlikely(ret)) { page = ERR_PTR(ret); goto out; @@ -1233,7 +1152,7 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address, goto unmap; *page = pte_page(entry); } - ret = try_grab_page(*page, gup_flags); + ret = try_grab_folio(page_folio(*page), 1, gup_flags); if (unlikely(ret)) goto unmap; out: @@ -1636,20 +1555,19 @@ static long __get_user_pages(struct mm_struct *mm, * pages. */ if (page_increm > 1) { - struct folio *folio; + struct folio *folio = page_folio(page); /* * Since we already hold refcount on the * large folio, this should never fail. */ - folio = try_grab_folio(page, page_increm - 1, - foll_flags); - if (WARN_ON_ONCE(!folio)) { + if (try_grab_folio(folio, page_increm - 1, + foll_flags)) { /* * Release the 1st page ref if the * folio is problematic, fail hard. */ - gup_put_folio(page_folio(page), 1, + gup_put_folio(folio, 1, foll_flags); ret = -EFAULT; goto out; @@ -2797,6 +2715,101 @@ EXPORT_SYMBOL(get_user_pages_unlocked); * This code is based heavily on the PowerPC implementation by Nick Piggin. */ #ifdef CONFIG_HAVE_GUP_FAST +/** + * try_grab_folio_fast() - Attempt to get or pin a folio in fast path. + * @page: pointer to page to be grabbed + * @refs: the value to (effectively) add to the folio's refcount + * @flags: gup flags: these are the FOLL_* flag values. + * + * "grab" names in this file mean, "look at flags to decide whether to use + * FOLL_PIN or FOLL_GET behavior, when incrementing the folio's refcount. + * + * Either FOLL_PIN or FOLL_GET (or neither) must be set, but not both at the + * same time. (That's true throughout the get_user_pages*() and + * pin_user_pages*() APIs.) Cases: + * + * FOLL_GET: folio's refcount will be incremented by @refs. + * + * FOLL_PIN on large folios: folio's refcount will be incremented by + * @refs, and its pincount will be incremented by @refs. + * + * FOLL_PIN on single-page folios: folio's refcount will be incremented by + * @refs * GUP_PIN_COUNTING_BIAS. + * + * Return: The folio containing @page (with refcount appropriately + * incremented) for success, or NULL upon failure. If neither FOLL_GET + * nor FOLL_PIN was set, that's considered failure, and furthermore, + * a likely bug in the caller, so a warning is also emitted. + * + * It uses add ref unless zero to elevate the folio refcount and must be called + * in fast path only. + */ +static struct folio *try_grab_folio_fast(struct page *page, int refs, + unsigned int flags) +{ + struct folio *folio; + + /* Raise warn if it is not called in fast GUP */ + VM_WARN_ON_ONCE(!irqs_disabled()); + + if (WARN_ON_ONCE((flags & (FOLL_GET | FOLL_PIN)) == 0)) + return NULL; + + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page))) + return NULL; + + if (flags & FOLL_GET) + return try_get_folio(page, refs); + + /* FOLL_PIN is set */ + + /* + * Don't take a pin on the zero page - it's not going anywhere + * and it is used in a *lot* of places. + */ + if (is_zero_page(page)) + return page_folio(page); + + folio = try_get_folio(page, refs); + if (!folio) + return NULL; + + /* + * Can't do FOLL_LONGTERM + FOLL_PIN gup fast path if not in a + * right zone, so fail and let the caller fall back to the slow + * path. + */ + if (unlikely((flags & FOLL_LONGTERM) && + !folio_is_longterm_pinnable(folio))) { + if (!put_devmap_managed_folio_refs(folio, refs)) + folio_put_refs(folio, refs); + return NULL; + } + + /* + * When pinning a large folio, use an exact count to track it. + * + * However, be sure to *also* increment the normal folio + * refcount field at least once, so that the folio really + * is pinned. That's why the refcount from the earlier + * try_get_folio() is left intact. + */ + if (folio_test_large(folio)) + atomic_add(refs, &folio->_pincount); + else + folio_ref_add(folio, + refs * (GUP_PIN_COUNTING_BIAS - 1)); + /* + * Adjust the pincount before re-checking the PTE for changes. + * This is essentially a smp_mb() and is paired with a memory + * barrier in folio_try_share_anon_rmap_*(). + */ + smp_mb__after_atomic(); + + node_stat_mod_folio(folio, NR_FOLL_PIN_ACQUIRED, refs); + + return folio; +} /* * Used in the GUP-fast path to determine whether GUP is permitted to work on @@ -2962,7 +2975,7 @@ static int gup_fast_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); - folio = try_grab_folio(page, 1, flags); + folio = try_grab_folio_fast(page, 1, flags); if (!folio) goto pte_unmap; @@ -3049,7 +3062,7 @@ static int gup_fast_devmap_leaf(unsigned long pfn, unsigned long addr, break; } - folio = try_grab_folio(page, 1, flags); + folio = try_grab_folio_fast(page, 1, flags); if (!folio) { gup_fast_undo_dev_pagemap(nr, nr_start, flags, pages); break; @@ -3138,7 +3151,7 @@ static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr, page = pmd_page(orig); refs = record_subpages(page, PMD_SIZE, addr, end, pages + *nr); - folio = try_grab_folio(page, refs, flags); + folio = try_grab_folio_fast(page, refs, flags); if (!folio) return 0; @@ -3182,7 +3195,7 @@ static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr, page = pud_page(orig); refs = record_subpages(page, PUD_SIZE, addr, end, pages + *nr); - folio = try_grab_folio(page, refs, flags); + folio = try_grab_folio_fast(page, refs, flags); if (!folio) return 0; @@ -3222,7 +3235,7 @@ static int gup_fast_pgd_leaf(pgd_t orig, pgd_t *pgdp, unsigned long addr, page = pgd_page(orig); refs = record_subpages(page, PGDIR_SIZE, addr, end, pages + *nr); - folio = try_grab_folio(page, refs, flags); + folio = try_grab_folio_fast(page, refs, flags); if (!folio) return 0; @@ -3276,7 +3289,8 @@ static int gup_fast_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, * pmd format and THP pmd format */ if (gup_hugepd(NULL, __hugepd(pmd_val(pmd)), addr, - PMD_SHIFT, next, flags, pages, nr) != 1) + PMD_SHIFT, next, flags, pages, nr, + true) != 1) return 0; } else if (!gup_fast_pte_range(pmd, pmdp, addr, next, flags, pages, nr)) @@ -3306,7 +3320,8 @@ static int gup_fast_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, return 0; } else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) { if (gup_hugepd(NULL, __hugepd(pud_val(pud)), addr, - PUD_SHIFT, next, flags, pages, nr) != 1) + PUD_SHIFT, next, flags, pages, nr, + true) != 1) return 0; } else if (!gup_fast_pmd_range(pudp, pud, addr, next, flags, pages, nr)) @@ -3333,7 +3348,8 @@ static int gup_fast_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, BUILD_BUG_ON(p4d_leaf(p4d)); if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) { if (gup_hugepd(NULL, __hugepd(p4d_val(p4d)), addr, - P4D_SHIFT, next, flags, pages, nr) != 1) + P4D_SHIFT, next, flags, pages, nr, + true) != 1) return 0; } else if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags, pages, nr)) @@ -3362,7 +3378,8 @@ static void gup_fast_pgd_range(unsigned long addr, unsigned long end, return; } else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) { if (gup_hugepd(NULL, __hugepd(pgd_val(pgd)), addr, - PGDIR_SHIFT, next, flags, pages, nr) != 1) + PGDIR_SHIFT, next, flags, pages, nr, + true) != 1) return; } else if (!gup_fast_p4d_range(pgdp, pgd, addr, next, flags, pages, nr)) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index db7946a0a28c..2120f7478e55 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1331,7 +1331,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, if (!*pgmap) return ERR_PTR(-EFAULT); page = pfn_to_page(pfn); - ret = try_grab_page(page, flags); + ret = try_grab_folio(page_folio(page), 1, flags); if (ret) page = ERR_PTR(ret); diff --git a/mm/internal.h b/mm/internal.h index 6902b7dd8509..cc2c5e07fad3 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1182,8 +1182,8 @@ int migrate_device_coherent_page(struct page *page); /* * mm/gup.c */ -struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags); -int __must_check try_grab_page(struct page *page, unsigned int flags); +int __must_check try_grab_folio(struct folio *folio, int refs, + unsigned int flags); /* * mm/huge_memory.c -- 2.41.0

3 months

2
1
0 0

[merged mm-stable] mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer has been removed from the -mm tree. Its filename was mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> Subject: mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer Date: Fri, 21 Jun 2024 10:08:41 +0900 Commit 2b5067a8143e ("mm: mmap_lock: add tracepoints around lock acquisition") introduced TRACE_MMAP_LOCK_EVENT() macro using preempt_disable() in order to let get_mm_memcg_path() return a percpu buffer exclusively used by normal, softirq, irq and NMI contexts respectively. Commit 832b50725373 ("mm: mmap_lock: use local locks instead of disabling preemption") replaced preempt_disable() with local_lock(&memcg_paths.lock) based on an argument that preempt_disable() has to be avoided because get_mm_memcg_path() might sleep if PREEMPT_RT=y. But syzbot started reporting inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. and inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. messages, for local_lock() does not disable IRQ. We could replace local_lock() with local_lock_irqsave() in order to suppress these messages. But this patch instead replaces percpu buffers with on-stack buffer, for the size of each buffer returned by get_memcg_path_buf() is only 256 bytes which is tolerable for allocating from current thread's kernel stack memory. Link: https://lkml.kernel.org/r/ef22d289-eadb-4ed9-863b-fbc922b33d8d@I-love.SAKUR… Reported-by: syzbot <syzbot+40905bca570ae6784745(a)syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=40905bca570ae6784745 Fixes: 832b50725373 ("mm: mmap_lock: use local locks instead of disabling preemption") Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> Reviewed-by: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Nicolas Saenz Julienne <nsaenzju(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/mmap_lock.c | 175 +++++------------------------------------------ 1 file changed, 20 insertions(+), 155 deletions(-) --- a/mm/mmap_lock.c~mm-mmap_lock-replace-get_memcg_path_buf-with-on-stack-buffer +++ a/mm/mmap_lock.c @@ -19,14 +19,7 @@ EXPORT_TRACEPOINT_SYMBOL(mmap_lock_relea #ifdef CONFIG_MEMCG -/* - * Our various events all share the same buffer (because we don't want or need - * to allocate a set of buffers *per event type*), so we need to protect against - * concurrent _reg() and _unreg() calls, and count how many _reg() calls have - * been made. - */ -static DEFINE_MUTEX(reg_lock); -static int reg_refcount; /* Protected by reg_lock. */ +static atomic_t reg_refcount; /* * Size of the buffer for memcg path names. Ignoring stack trace support, @@ -34,136 +27,22 @@ static int reg_refcount; /* Protected by */ #define MEMCG_PATH_BUF_SIZE MAX_FILTER_STR_VAL -/* - * How many contexts our trace events might be called in: normal, softirq, irq, - * and NMI. - */ -#define CONTEXT_COUNT 4 - -struct memcg_path { - local_lock_t lock; - char __rcu *buf; - local_t buf_idx; -}; -static DEFINE_PER_CPU(struct memcg_path, memcg_paths) = { - .lock = INIT_LOCAL_LOCK(lock), - .buf_idx = LOCAL_INIT(0), -}; - -static char **tmp_bufs; - -/* Called with reg_lock held. */ -static void free_memcg_path_bufs(void) -{ - struct memcg_path *memcg_path; - int cpu; - char **old = tmp_bufs; - - for_each_possible_cpu(cpu) { - memcg_path = per_cpu_ptr(&memcg_paths, cpu); - *(old++) = rcu_dereference_protected(memcg_path->buf, - lockdep_is_held(&reg_lock)); - rcu_assign_pointer(memcg_path->buf, NULL); - } - - /* Wait for inflight memcg_path_buf users to finish. */ - synchronize_rcu(); - - old = tmp_bufs; - for_each_possible_cpu(cpu) { - kfree(*(old++)); - } - - kfree(tmp_bufs); - tmp_bufs = NULL; -} - int trace_mmap_lock_reg(void) { - int cpu; - char *new; - - mutex_lock(&reg_lock); - - /* If the refcount is going 0->1, proceed with allocating buffers. */ - if (reg_refcount++) - goto out; - - tmp_bufs = kmalloc_array(num_possible_cpus(), sizeof(*tmp_bufs), - GFP_KERNEL); - if (tmp_bufs == NULL) - goto out_fail; - - for_each_possible_cpu(cpu) { - new = kmalloc(MEMCG_PATH_BUF_SIZE * CONTEXT_COUNT, GFP_KERNEL); - if (new == NULL) - goto out_fail_free; - rcu_assign_pointer(per_cpu_ptr(&memcg_paths, cpu)->buf, new); - /* Don't need to wait for inflights, they'd have gotten NULL. */ - } - -out: - mutex_unlock(&reg_lock); + atomic_inc(&reg_refcount); return 0; - -out_fail_free: - free_memcg_path_bufs(); -out_fail: - /* Since we failed, undo the earlier ref increment. */ - --reg_refcount; - - mutex_unlock(&reg_lock); - return -ENOMEM; } void trace_mmap_lock_unreg(void) { - mutex_lock(&reg_lock); - - /* If the refcount is going 1->0, proceed with freeing buffers. */ - if (--reg_refcount) - goto out; - - free_memcg_path_bufs(); - -out: - mutex_unlock(&reg_lock); -} - -static inline char *get_memcg_path_buf(void) -{ - struct memcg_path *memcg_path = this_cpu_ptr(&memcg_paths); - char *buf; - int idx; - - rcu_read_lock(); - buf = rcu_dereference(memcg_path->buf); - if (buf == NULL) { - rcu_read_unlock(); - return NULL; - } - idx = local_add_return(MEMCG_PATH_BUF_SIZE, &memcg_path->buf_idx) - - MEMCG_PATH_BUF_SIZE; - return &buf[idx]; + atomic_dec(&reg_refcount); } -static inline void put_memcg_path_buf(void) -{ - local_sub(MEMCG_PATH_BUF_SIZE, &this_cpu_ptr(&memcg_paths)->buf_idx); - rcu_read_unlock(); -} - -#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \ - do { \ - const char *memcg_path; \ - local_lock(&memcg_paths.lock); \ - memcg_path = get_mm_memcg_path(mm); \ - trace_mmap_lock_##type(mm, \ - memcg_path != NULL ? memcg_path : "", \ - ##__VA_ARGS__); \ - if (likely(memcg_path != NULL)) \ - put_memcg_path_buf(); \ - local_unlock(&memcg_paths.lock); \ +#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \ + do { \ + char buf[MEMCG_PATH_BUF_SIZE]; \ + get_mm_memcg_path(mm, buf, sizeof(buf)); \ + trace_mmap_lock_##type(mm, buf, ##__VA_ARGS__); \ } while (0) #else /* !CONFIG_MEMCG */ @@ -185,37 +64,23 @@ void trace_mmap_lock_unreg(void) #ifdef CONFIG_TRACING #ifdef CONFIG_MEMCG /* - * Write the given mm_struct's memcg path to a percpu buffer, and return a - * pointer to it. If the path cannot be determined, or no buffer was available - * (because the trace event is being unregistered), NULL is returned. - * - * Note: buffers are allocated per-cpu to avoid locking, so preemption must be - * disabled by the caller before calling us, and re-enabled only after the - * caller is done with the pointer. - * - * The caller must call put_memcg_path_buf() once the buffer is no longer - * needed. This must be done while preemption is still disabled. + * Write the given mm_struct's memcg path to a buffer. If the path cannot be + * determined or the trace event is being unregistered, empty string is written. */ -static const char *get_mm_memcg_path(struct mm_struct *mm) +static void get_mm_memcg_path(struct mm_struct *mm, char *buf, size_t buflen) { - char *buf = NULL; - struct mem_cgroup *memcg = get_mem_cgroup_from_mm(mm); + struct mem_cgroup *memcg; + buf[0] = '\0'; + /* No need to get path if no trace event is registered. */ + if (!atomic_read(&reg_refcount)) + return; + memcg = get_mem_cgroup_from_mm(mm); if (memcg == NULL) - goto out; - if (unlikely(memcg->css.cgroup == NULL)) - goto out_put; - - buf = get_memcg_path_buf(); - if (buf == NULL) - goto out_put; - - cgroup_path(memcg->css.cgroup, buf, MEMCG_PATH_BUF_SIZE); - -out_put: + return; + if (memcg->css.cgroup) + cgroup_path(memcg->css.cgroup, buf, buflen); css_put(&memcg->css); -out: - return buf; } #endif /* CONFIG_MEMCG */ _ Patches currently in -mm which might be from penguin-kernel(a)I-love.SAKURA.ne.jp are

3 months

1
0
0 0

[PATCH v2] i2c: aspeed: Update the stop sw state when the bus recovery occurs

by Tommy Huang

When the i2c bus recovery occurs, driver will send i2c stop command in the scl low condition. In this case the sw state will still keep original situation. Under multi-master usage, i2c bus recovery will be called when i2c transfer timeout occurs. Update the stop command calling with aspeed_i2c_do_stop function to update master_state. Fixes: f327c686d3ba ("i2c: aspeed: added driver for Aspeed I2C") Cc: <stable(a)vger.kernel.org> # v4.13+ Signed-off-by: Tommy Huang <tommy_huang(a)aspeedtech.com> --- drivers/i2c/busses/i2c-aspeed.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index ce8c4846b7fa..be64e419adf0 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -25,6 +25,8 @@ #include <linux/reset.h> #include <linux/slab.h> +static void aspeed_i2c_do_stop(struct aspeed_i2c_bus *bus); + /* I2C Register */ #define ASPEED_I2C_FUN_CTRL_REG 0x00 #define ASPEED_I2C_AC_TIMING_REG1 0x04 @@ -187,7 +189,7 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus) command); reinit_completion(&bus->cmd_complete); - writel(ASPEED_I2CD_M_STOP_CMD, bus->base + ASPEED_I2C_CMD_REG); + aspeed_i2c_do_stop(bus); spin_unlock_irqrestore(&bus->lock, flags); time_left = wait_for_completion_timeout( -- 2.25.1

3 months

3
4
0 0

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror June 2024