April 2024 - Linux-stable-mirror

[PATCH v2] scsi: sg: Avoid race in error handling & drop bogus warn

by Alexander Wetzel

commit 27f58c04a8f4 ("scsi: sg: Avoid sg device teardown race") introduced an incorrect WARN_ON_ONCE() and missed a sequence where sg_device_destroy() was used after scsi_device_put(). sg_device_destroy() is accessing the parent scsi_device request_queue which will already be set to NULL when the preceding call to scsi_device_put() removed the last reference to the parent scsi_device. Drop the incorrect WARN_ON_ONCE() - allowing more than one concurrent access to the sg device - and make sure sg_device_destroy() is not used after scsi_device_put() in the error handling. Link: https://lore.kernel.org/all/5375B275-D137-4D5F-BE25-6AF8ACAE41EF@linux.ibm.… Fixes: 27f58c04a8f4 ("scsi: sg: Avoid sg device teardown race") Cc: stable(a)vger.kernel.org Signed-off-by: Alexander Wetzel <Alexander(a)wetzel-home.de> --- Changes compared to V1: fixed commit message The WARN_ON_ONCE() was kind of stupid to add: We get add reference for each sg_open(). So opening a second session and then closing either one will trigger the warning... Nothing to warn about here. Alexander --- drivers/scsi/sg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 386981c6976a..833c9277419b 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -372,8 +372,9 @@ sg_open(struct inode *inode, struct file *filp) error_out: scsi_autopm_put_device(sdp->device); sdp_put: + kref_put(&sdp->d_ref, sg_device_destroy); scsi_device_put(sdp->device); - goto sg_put; + return retval; } /* Release resources associated with a successful sg_open() @@ -2233,7 +2234,6 @@ sg_remove_sfp_usercontext(struct work_struct *work) "sg_remove_sfp: sfp=0x%p\n", sfp)); kfree(sfp); - WARN_ON_ONCE(kref_read(&sdp->d_ref) != 1); kref_put(&sdp->d_ref, sg_device_destroy); scsi_device_put(device); module_put(THIS_MODULE); -- 2.44.0

8 months, 3 weeks

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[PATCH] sched/fair: Fix forked task check in vruntime_normalized

by mingyang.cui

When rt_mutex_setprio changes a task's scheduling class to RT, sometimes the task's vruntime is not updated correctly upon return to the fair class. Specifically, the following is being observed: - task has just been created and running for a short time - task sleep while still in the fair class - task is boosted to RT via rt_mutex_setprio, which changes the task to RT and calls check_class_changed. - check_class_changed leads to detach_task_cfs_rq, at which point the vruntime_normalized check sees that the task's sum_exec_runtime is zero, which results in skipping the subtraction of the rq's min_vruntime from the task's vruntime - later, when the prio is deboosted and the task is moved back to the fair class, the fair rq's min_vruntime is added to the task's vruntime, even though it wasn't subtracted earlier. Since the task's vruntime is about double that of other tasks in cfs_rq, the task to be unable to run for a long time when there are continuous runnable tasks in cfs_rq. The immediate result is inflation of the task's vruntime, giving it lower priority (starving it if there's enough available work). The longer-term effect is inflation of all vruntimes because the task's vruntime becomes the rq's min_vruntime when the higher priority tasks go idle. That leads to a vicious cycle, where the vruntime inflation repeatedly doubled. The root cause of the problem is that the vruntime_normalized made a misjudgment. Since the sum_exec_runtime of some tasks that were just created and run for a short time is zero, the vruntime_normalized mistakenly thinks that they are tasks that have just been forked. Therefore, sum_exec_runtime is not subtracted from the vruntime of the task. So, we fix this bug by adding a check condition for newly forked task. Signed-off-by: mingyang.cui <mingyang.cui(a)horizon.ai> --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 73a89fbd81be..3d0c14f3731f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -11112,7 +11112,7 @@ static inline bool vruntime_normalized(struct task_struct *p) * - A task which has been woken up by try_to_wake_up() and * waiting for actually being woken up by sched_ttwu_pending(). */ - if (!se->sum_exec_runtime || + if (!se->sum_exec_runtime && p->state == TASK_NEW || (p->state == TASK_WAKING && p->sched_remote_wakeup)) return true; -- 2.34.1

8 months, 4 weeks

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[PATCH 2/2] io_uring: disable io-wq execution of multishot NOWAIT requests

by Jens Axboe

Do the same check for direct io-wq execution for multishot requests that commit 2a975d426c82 did for the inline execution, and disable multishot mode (and revert to single shot) if the file type doesn't support NOWAIT, and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's a requirement that nonblocking read attempts can be done. Cc: stable(a)vger.kernel.org Signed-off-by: Jens Axboe <axboe(a)kernel.dk> --- io_uring/io_uring.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 5d4b448fdc50..8baf8afb79c2 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1982,10 +1982,15 @@ void io_wq_submit_work(struct io_wq_work *work) err = -EBADFD; if (!io_file_can_poll(req)) goto fail; - err = -ECANCELED; - if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK) - goto fail; - return; + if (req->file->f_flags & O_NONBLOCK || + req->file->f_mode & FMODE_NOWAIT) { + err = -ECANCELED; + if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK) + goto fail; + return; + } else { + req->flags &= ~REQ_F_APOLL_MULTISHOT; + } } if (req->flags & REQ_F_FORCE_ASYNC) { -- 2.43.0

8 months, 4 weeks

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[PATCH 1/2] io_uring/rw: don't allow multishot reads without NOWAIT support

by Jens Axboe

Supporting multishot reads requires support for NOWAIT, as the alternative would be always having io-wq execute the work item whenever the poll readiness triggered. Any fast file type will have NOWAIT support (eg it understands both O_NONBLOCK and IOCB_NOWAIT). If the given file type does not, then simply resort to single shot execution. Cc: stable(a)vger.kernel.org Fixes: fc68fcda04910 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT") Signed-off-by: Jens Axboe <axboe(a)kernel.dk> --- io_uring/rw.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/io_uring/rw.c b/io_uring/rw.c index 0585ebcc9773..c8d48287439e 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -936,6 +936,13 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) ret = __io_read(req, issue_flags); + /* + * If the file doesn't support proper NOWAIT, then disable multishot + * and stay in single shot mode. + */ + if (!io_file_supports_nowait(req)) + req->flags &= ~REQ_F_APOLL_MULTISHOT; + /* * If we get -EAGAIN, recycle our buffer and just let normal poll * handling arm it. @@ -955,7 +962,7 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) /* * Any successful return value will keep the multishot read armed. */ - if (ret > 0) { + if (ret > 0 && req->flags & REQ_F_APOLL_MULTISHOT) { /* * Put our buffer and post a CQE. If we fail to post a CQE, then * jump to the termination path. This request is then done. -- 2.43.0

8 months, 4 weeks

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Re: [PATCH 6.8 000/399] 6.8.3-rc1 review

by Ronald Warsow

Hi Greg *no* regressions here on x86_64 (RKL, Intel 11th Gen. CPU) Thanks Tested-by: Ronald Warsow <rwarsow(a)gmx.de>

8 months, 4 weeks

1
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Fwd: stable kernels 6.6.23 and 6.1.83 fails to build: error: unknown type name 'u32'

by Bagas Sanjaya

Hi, On Bugzilla, ncopa(a)alpinelinux.org reported resolve_btfids FTBFS regression on musl system [1]: > The latest releases fails to build with musl libc (Alpine Linux edge and v3.19): > > ``` > rm -f -f /home/ncopa/aports/main/linux-lts/src/build-lts.x86_64/tools/bpf/resolve_btfids/libbpf/libbpf.a; ar rcs /home/ncopa/aports/main/linux-lts/src/build-lts.x86_64/tool > s/bpf/resolve_btfids/libbpf/libbpf.a /home/ncopa/aports/main/linux-lts/src/build-lts.x86_64/tools/bpf/resolve_btfids/libbpf/staticobjs/libbpf-in.o > In file included from main.c:73: > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:7:9: error: unknown type name 'u32' > 7 | u32 cnt; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:8:9: error: unknown type name 'u32' > 8 | u32 ids[]; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:12:9: error: unknown type name 'u32' > 12 | u32 cnt; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:13:9: error: unknown type name 'u32' > 13 | u32 flags; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:15:17: error: unknown type name 'u32' > 15 | u32 id; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:16:17: error: unknown type name 'u32' > 16 | u32 flags; > | ^~~ > /home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/include/linux/btf_ids.h:215:8: error: unknown type name 'u32' > 215 | extern u32 btf_tracing_ids[]; > | ^~~ > make[4]: *** [/home/ncopa/aports/main/linux-lts/src/linux-6.6/tools/build/Makefile.build:98: /home/ncopa/aports/main/linux-lts/src/build-lts.x86_64/tools/bpf/resolve_btfids > /main.o] Error 1 > make[4]: *** Waiting for unfinished jobs.... > make[3]: *** [Makefile:83: /home/ncopa/aports/main/linux-lts/src/build-lts.x86_64/tools/bpf/resolve_btfids//resolve_btfids-in.o] Error 2 > make[2]: *** [Makefile:76: bpf/resolve_btfids] Error 2 > make[1]: *** [/home/ncopa/aports/main/linux-lts/src/linux-6.6/Makefile:1354: tools/bpf/resolve_btfids] Error 2 > make: *** [/home/ncopa/aports/main/linux-lts/src/linux-6.6/Makefile:234: __sub-make] Error 2 > ``` Bisection led to upstream commit 9707ac4fe2f5ba ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h") as the culprit. See the report on Bugzilla for the full thread and proposed fix. Thanks. [1]: https://bugzilla.kernel.org/show_bug.cgi?id=218647 -- An old man doll... just what I always wanted! - Clara

8 months, 4 weeks

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FAILED: patch "[PATCH] USB: core: Fix deadlock in usb_deauthorize_interface()" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-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-4.19.y git checkout FETCH_HEAD git cherry-pick -x 80ba43e9f799cbdd83842fc27db667289b3150f5 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040157-entrench-clicker-d3df@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: 80ba43e9f799 ("USB: core: Fix deadlock in usb_deauthorize_interface()") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 80ba43e9f799cbdd83842fc27db667289b3150f5 Mon Sep 17 00:00:00 2001 From: Alan Stern <stern(a)rowland.harvard.edu> Date: Tue, 12 Mar 2024 11:48:23 -0400 Subject: [PATCH] USB: core: Fix deadlock in usb_deauthorize_interface() Among the attribute file callback routines in drivers/usb/core/sysfs.c, the interface_authorized_store() function is the only one which acquires a device lock on an ancestor device: It calls usb_deauthorize_interface(), which locks the interface's parent USB device. The will lead to deadlock if another process already owns that lock and tries to remove the interface, whether through a configuration change or because the device has been disconnected. As part of the removal procedure, device_del() waits for all ongoing sysfs attribute callbacks to complete. But usb_deauthorize_interface() can't complete until the device lock has been released, and the lock won't be released until the removal has finished. The mechanism provided by sysfs to prevent this kind of deadlock is to use the sysfs_break_active_protection() function, which tells sysfs not to wait for the attribute callback. Reported-and-tested by: Yue Sun <samsun1006219(a)gmail.com> Reported by: xingwei lee <xrivendell7(a)gmail.com> Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu> Link: https://lore.kernel.org/linux-usb/CAEkJfYO6jRVC8Tfrd_R=cjO0hguhrV31fDPrLrNO… Fixes: 310d2b4124c0 ("usb: interface authorization: SysFS part of USB interface authorization") Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/1c37eea1-9f56-4534-b9d8-b443438dc869@rowland.harv… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index f98263e21c2a..d83231d6736a 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -1217,14 +1217,24 @@ static ssize_t interface_authorized_store(struct device *dev, { struct usb_interface *intf = to_usb_interface(dev); bool val; + struct kernfs_node *kn; if (kstrtobool(buf, &val) != 0) return -EINVAL; - if (val) + if (val) { usb_authorize_interface(intf); - else - usb_deauthorize_interface(intf); + } else { + /* + * Prevent deadlock if another process is concurrently + * trying to unregister intf. + */ + kn = sysfs_break_active_protection(&dev->kobj, &attr->attr); + if (kn) { + usb_deauthorize_interface(intf); + sysfs_unbreak_active_protection(kn); + } + } return count; }

8 months, 4 weeks

3
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FAILED: patch "[PATCH] x86/sev: Skip ROM range scans and validation for SEV-SNP" failed to apply to 6.8-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.8-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-6.8.y git checkout FETCH_HEAD git cherry-pick -x 0f4a1e80989aca185d955fcd791d7750082044a2 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040102-umbrella-nag-c677@gregkh' --subject-prefix 'PATCH 6.8.y' HEAD^.. Possible dependencies: 0f4a1e80989a ("x86/sev: Skip ROM range scans and validation for SEV-SNP guests") 428080c9b19b ("x86/sev: Move early startup code into .head.text section") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0f4a1e80989aca185d955fcd791d7750082044a2 Mon Sep 17 00:00:00 2001 From: Kevin Loughlin <kevinloughlin(a)google.com> Date: Wed, 13 Mar 2024 12:15:46 +0000 Subject: [PATCH] x86/sev: Skip ROM range scans and validation for SEV-SNP guests SEV-SNP requires encrypted memory to be validated before access. Because the ROM memory range is not part of the e820 table, it is not pre-validated by the BIOS. Therefore, if a SEV-SNP guest kernel wishes to access this range, the guest must first validate the range. The current SEV-SNP code does indeed scan the ROM range during early boot and thus attempts to validate the ROM range in probe_roms(). However, this behavior is neither sufficient nor necessary for the following reasons: * With regards to sufficiency, if EFI_CONFIG_TABLES are not enabled and CONFIG_DMI_SCAN_MACHINE_NON_EFI_FALLBACK is set, the kernel will attempt to access the memory at SMBIOS_ENTRY_POINT_SCAN_START (which falls in the ROM range) prior to validation. For example, Project Oak Stage 0 provides a minimal guest firmware that currently meets these configuration conditions, meaning guests booting atop Oak Stage 0 firmware encounter a problematic call chain during dmi_setup() -> dmi_scan_machine() that results in a crash during boot if SEV-SNP is enabled. * With regards to necessity, SEV-SNP guests generally read garbage (which changes across boots) from the ROM range, meaning these scans are unnecessary. The guest reads garbage because the legacy ROM range is unencrypted data but is accessed via an encrypted PMD during early boot (where the PMD is marked as encrypted due to potentially mapping actually-encrypted data in other PMD-contained ranges). In one exceptional case, EISA probing treats the ROM range as unencrypted data, which is inconsistent with other probing. Continuing to allow SEV-SNP guests to use garbage and to inconsistently classify ROM range encryption status can trigger undesirable behavior. For instance, if garbage bytes appear to be a valid signature, memory may be unnecessarily reserved for the ROM range. Future code or other use cases may result in more problematic (arbitrary) behavior that should be avoided. While one solution would be to overhaul the early PMD mapping to always treat the ROM region of the PMD as unencrypted, SEV-SNP guests do not currently rely on data from the ROM region during early boot (and even if they did, they would be mostly relying on garbage data anyways). As a simpler solution, skip the ROM range scans (and the otherwise- necessary range validation) during SEV-SNP guest early boot. The potential SEV-SNP guest crash due to lack of ROM range validation is thus avoided by simply not accessing the ROM range. In most cases, skip the scans by overriding problematic x86_init functions during sme_early_init() to SNP-safe variants, which can be likened to x86_init overrides done for other platforms (ex: Xen); such overrides also avoid the spread of cc_platform_has() checks throughout the tree. In the exceptional EISA case, still use cc_platform_has() for the simplest change, given (1) checks for guest type (ex: Xen domain status) are already performed here, and (2) these checks occur in a subsys initcall instead of an x86_init function. [ bp: Massage commit message, remove "we"s. ] Fixes: 9704c07bf9f7 ("x86/kernel: Validate ROM memory before accessing when SEV-SNP is active") Signed-off-by: Kevin Loughlin <kevinloughlin(a)google.com> Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: <stable(a)kernel.org> Link: https://lore.kernel.org/r/20240313121546.2964854-1-kevinloughlin@google.com diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 9477b4053bce..07e125f32528 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -218,12 +218,12 @@ void early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages); void early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages); -void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op); void snp_set_memory_shared(unsigned long vaddr, unsigned long npages); void snp_set_memory_private(unsigned long vaddr, unsigned long npages); void snp_set_wakeup_secondary_cpu(void); bool snp_init(struct boot_params *bp); void __noreturn snp_abort(void); +void snp_dmi_setup(void); int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio); void snp_accept_memory(phys_addr_t start, phys_addr_t end); u64 snp_get_unsupported_features(u64 status); @@ -244,12 +244,12 @@ static inline void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { } static inline void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { } -static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { } static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { } static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { } static inline void snp_set_wakeup_secondary_cpu(void) { } static inline bool snp_init(struct boot_params *bp) { return false; } static inline void snp_abort(void) { } +static inline void snp_dmi_setup(void) { } static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, struct snp_guest_request_ioctl *rio) { return -ENOTTY; diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index b89b40f250e6..6149eabe200f 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -30,12 +30,13 @@ struct x86_init_mpparse { * @reserve_resources: reserve the standard resources for the * platform * @memory_setup: platform specific memory setup - * + * @dmi_setup: platform specific DMI setup */ struct x86_init_resources { void (*probe_roms)(void); void (*reserve_resources)(void); char *(*memory_setup)(void); + void (*dmi_setup)(void); }; /** diff --git a/arch/x86/kernel/eisa.c b/arch/x86/kernel/eisa.c index e963344b0449..53935b4d62e3 100644 --- a/arch/x86/kernel/eisa.c +++ b/arch/x86/kernel/eisa.c @@ -2,6 +2,7 @@ /* * EISA specific code */ +#include <linux/cc_platform.h> #include <linux/ioport.h> #include <linux/eisa.h> #include <linux/io.h> @@ -12,7 +13,7 @@ static __init int eisa_bus_probe(void) { void __iomem *p; - if (xen_pv_domain() && !xen_initial_domain()) + if ((xen_pv_domain() && !xen_initial_domain()) || cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return 0; p = ioremap(0x0FFFD9, 4); diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c index 319fef37d9dc..cc2c34ba7228 100644 --- a/arch/x86/kernel/probe_roms.c +++ b/arch/x86/kernel/probe_roms.c @@ -203,16 +203,6 @@ void __init probe_roms(void) unsigned char c; int i; - /* - * The ROM memory range is not part of the e820 table and is therefore not - * pre-validated by BIOS. The kernel page table maps the ROM region as encrypted - * memory, and SNP requires encrypted memory to be validated before access. - * Do that here. - */ - snp_prep_memory(video_rom_resource.start, - ((system_rom_resource.end + 1) - video_rom_resource.start), - SNP_PAGE_STATE_PRIVATE); - /* video rom */ upper = adapter_rom_resources[0].start; for (start = video_rom_resource.start; start < upper; start += 2048) { diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index ef206500ed6f..0109e6c510e0 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -9,7 +9,6 @@ #include <linux/console.h> #include <linux/crash_dump.h> #include <linux/dma-map-ops.h> -#include <linux/dmi.h> #include <linux/efi.h> #include <linux/ima.h> #include <linux/init_ohci1394_dma.h> @@ -902,7 +901,7 @@ void __init setup_arch(char **cmdline_p) efi_init(); reserve_ibft_region(); - dmi_setup(); + x86_init.resources.dmi_setup(); /* * VMware detection requires dmi to be available, so this diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index b59b09c2f284..7e1e63cc48e6 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -23,6 +23,7 @@ #include <linux/platform_device.h> #include <linux/io.h> #include <linux/psp-sev.h> +#include <linux/dmi.h> #include <uapi/linux/sev-guest.h> #include <asm/init.h> @@ -795,21 +796,6 @@ void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_SHARED); } -void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) -{ - unsigned long vaddr, npages; - - vaddr = (unsigned long)__va(paddr); - npages = PAGE_ALIGN(sz) >> PAGE_SHIFT; - - if (op == SNP_PAGE_STATE_PRIVATE) - early_snp_set_memory_private(vaddr, paddr, npages); - else if (op == SNP_PAGE_STATE_SHARED) - early_snp_set_memory_shared(vaddr, paddr, npages); - else - WARN(1, "invalid memory op %d\n", op); -} - static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr, unsigned long vaddr_end, int op) { @@ -2136,6 +2122,17 @@ void __head __noreturn snp_abort(void) sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); } +/* + * SEV-SNP guests should only execute dmi_setup() if EFI_CONFIG_TABLES are + * enabled, as the alternative (fallback) logic for DMI probing in the legacy + * ROM region can cause a crash since this region is not pre-validated. + */ +void __init snp_dmi_setup(void) +{ + if (efi_enabled(EFI_CONFIG_TABLES)) + dmi_setup(); +} + static void dump_cpuid_table(void) { const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index a42830dc151b..d5dc5a92635a 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -3,6 +3,7 @@ * * For licencing details see kernel-base/COPYING */ +#include <linux/dmi.h> #include <linux/init.h> #include <linux/ioport.h> #include <linux/export.h> @@ -66,6 +67,7 @@ struct x86_init_ops x86_init __initdata = { .probe_roms = probe_roms, .reserve_resources = reserve_standard_io_resources, .memory_setup = e820__memory_setup_default, + .dmi_setup = dmi_setup, }, .mpparse = { diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c index 70b91de2e053..422602f6039b 100644 --- a/arch/x86/mm/mem_encrypt_amd.c +++ b/arch/x86/mm/mem_encrypt_amd.c @@ -492,6 +492,24 @@ void __init sme_early_init(void) */ if (sev_status & MSR_AMD64_SEV_ENABLED) ia32_disable(); + + /* + * Override init functions that scan the ROM region in SEV-SNP guests, + * as this memory is not pre-validated and would thus cause a crash. + */ + if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) { + x86_init.mpparse.find_mptable = x86_init_noop; + x86_init.pci.init_irq = x86_init_noop; + x86_init.resources.probe_roms = x86_init_noop; + + /* + * DMI setup behavior for SEV-SNP guests depends on + * efi_enabled(EFI_CONFIG_TABLES), which hasn't been + * parsed yet. snp_dmi_setup() will run after that + * parsing has happened. + */ + x86_init.resources.dmi_setup = snp_dmi_setup; + } } void __init mem_encrypt_free_decrypted_mem(void)

8 months, 4 weeks

3
2
0 0

FAILED: patch "[PATCH] perf/x86/amd/lbr: Use freeze based on availability" failed to apply to 6.7-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.7-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-6.7.y git checkout FETCH_HEAD git cherry-pick -x 598c2fafc06fe5c56a1a415fb7b544b31453d637 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040153-joyfully-negate-6062@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^.. Possible dependencies: 598c2fafc06f ("perf/x86/amd/lbr: Use freeze based on availability") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 598c2fafc06fe5c56a1a415fb7b544b31453d637 Mon Sep 17 00:00:00 2001 From: Sandipan Das <sandipan.das(a)amd.com> Date: Mon, 25 Mar 2024 13:01:45 +0530 Subject: [PATCH] perf/x86/amd/lbr: Use freeze based on availability Currently, the LBR code assumes that LBR Freeze is supported on all processors when X86_FEATURE_AMD_LBR_V2 is available i.e. CPUID leaf 0x80000022[EAX] bit 1 is set. This is incorrect as the availability of the feature is additionally dependent on CPUID leaf 0x80000022[EAX] bit 2 being set, which may not be set for all Zen 4 processors. Define a new feature bit for LBR and PMC freeze and set the freeze enable bit (FLBRI) in DebugCtl (MSR 0x1d9) conditionally. It should still be possible to use LBR without freeze for profile-guided optimization of user programs by using an user-only branch filter during profiling. When the user-only filter is enabled, branches are no longer recorded after the transition to CPL 0 upon PMI arrival. When branch entries are read in the PMI handler, the branch stack does not change. E.g. $ perf record -j any,u -e ex_ret_brn_tkn ./workload Since the feature bit is visible under flags in /proc/cpuinfo, it can be used to determine the feasibility of use-cases which require LBR Freeze to be supported by the hardware such as profile-guided optimization of kernels. Fixes: ca5b7c0d9621 ("perf/x86/amd/lbr: Add LbrExtV2 branch record support") Signed-off-by: Sandipan Das <sandipan.das(a)amd.com> Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Link: https://lore.kernel.org/r/69a453c97cfd11c6f2584b19f937fe6df741510f.17110915… diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index aec16e581f5b..5692e827afef 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -904,8 +904,8 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs) if (!status) goto done; - /* Read branch records before unfreezing */ - if (status & GLOBAL_STATUS_LBRS_FROZEN) { + /* Read branch records */ + if (x86_pmu.lbr_nr) { amd_pmu_lbr_read(); status &= ~GLOBAL_STATUS_LBRS_FROZEN; } diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c index 4a1e600314d5..5149830c7c4f 100644 --- a/arch/x86/events/amd/lbr.c +++ b/arch/x86/events/amd/lbr.c @@ -402,10 +402,12 @@ void amd_pmu_lbr_enable_all(void) wrmsrl(MSR_AMD64_LBR_SELECT, lbr_select); } - rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); - rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg); + if (cpu_feature_enabled(X86_FEATURE_AMD_LBR_PMC_FREEZE)) { + rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); + wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); + } - wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); + rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg); wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg | DBG_EXTN_CFG_LBRV2EN); } @@ -418,10 +420,12 @@ void amd_pmu_lbr_disable_all(void) return; rdmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg); - rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); - wrmsrl(MSR_AMD_DBG_EXTN_CFG, dbg_extn_cfg & ~DBG_EXTN_CFG_LBRV2EN); - wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); + + if (cpu_feature_enabled(X86_FEATURE_AMD_LBR_PMC_FREEZE)) { + rdmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl); + wrmsrl(MSR_IA32_DEBUGCTLMSR, dbg_ctl & ~DEBUGCTLMSR_FREEZE_LBRS_ON_PMI); + } } __init int amd_pmu_lbr_init(void) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 4d850a780f7e..a38f8f9ba657 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -459,6 +459,14 @@ #define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* "" MSR_PRED_CMD[IBPB] flushes all branch type predictions */ #define X86_FEATURE_SRSO_NO (20*32+29) /* "" CPU is not affected by SRSO */ +/* + * Extended auxiliary flags: Linux defined - for features scattered in various + * CPUID levels like 0x80000022, etc. + * + * Reuse free bits when adding new feature flags! + */ +#define X86_FEATURE_AMD_LBR_PMC_FREEZE (21*32+ 0) /* AMD LBR and PMC Freeze */ + /* * BUG word(s) */ diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index 0dad49a09b7a..a515328d9d7d 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -49,6 +49,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 }, { X86_FEATURE_PERFMON_V2, CPUID_EAX, 0, 0x80000022, 0 }, { X86_FEATURE_AMD_LBR_V2, CPUID_EAX, 1, 0x80000022, 0 }, + { X86_FEATURE_AMD_LBR_PMC_FREEZE, CPUID_EAX, 2, 0x80000022, 0 }, { 0, 0, 0, 0, 0 } };

8 months, 4 weeks

1
0
0 0

FAILED: patch "[PATCH] perf/x86/amd/core: Update and fix stalled-cycles-* events for" failed to apply to 6.7-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.7-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-6.7.y git checkout FETCH_HEAD git cherry-pick -x c7b2edd8377be983442c1344cb940cd2ac21b601 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024040125-viability-refined-29d0@gregkh' --subject-prefix 'PATCH 6.7.y' HEAD^.. Possible dependencies: c7b2edd8377b ("perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c7b2edd8377be983442c1344cb940cd2ac21b601 Mon Sep 17 00:00:00 2001 From: Sandipan Das <sandipan.das(a)amd.com> Date: Mon, 25 Mar 2024 13:17:53 +0530 Subject: [PATCH] perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later AMD processors based on Zen 2 and later microarchitectures do not support PMCx087 (instruction pipe stalls) which is used as the backing event for "stalled-cycles-frontend" and "stalled-cycles-backend". Use PMCx0A9 (cycles where micro-op queue is empty) instead to count frontend stalls and remove the entry for backend stalls since there is no direct replacement. Signed-off-by: Sandipan Das <sandipan.das(a)amd.com> Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Reviewed-by: Ian Rogers <irogers(a)google.com> Fixes: 3fe3331bb285 ("perf/x86/amd: Add event map for AMD Family 17h") Link: https://lore.kernel.org/r/03d7fc8fa2a28f9be732116009025bdec1b3ec97.17113521… diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index 5692e827afef..af8add6c11ea 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -250,7 +250,7 @@ static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] = /* * AMD Performance Monitor Family 17h and later: */ -static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] = +static const u64 amd_zen1_perfmon_event_map[PERF_COUNT_HW_MAX] = { [PERF_COUNT_HW_CPU_CYCLES] = 0x0076, [PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0, @@ -262,10 +262,24 @@ static const u64 amd_f17h_perfmon_event_map[PERF_COUNT_HW_MAX] = [PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x0187, }; +static const u64 amd_zen2_perfmon_event_map[PERF_COUNT_HW_MAX] = +{ + [PERF_COUNT_HW_CPU_CYCLES] = 0x0076, + [PERF_COUNT_HW_INSTRUCTIONS] = 0x00c0, + [PERF_COUNT_HW_CACHE_REFERENCES] = 0xff60, + [PERF_COUNT_HW_CACHE_MISSES] = 0x0964, + [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x00c2, + [PERF_COUNT_HW_BRANCH_MISSES] = 0x00c3, + [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x00a9, +}; + static u64 amd_pmu_event_map(int hw_event) { - if (boot_cpu_data.x86 >= 0x17) - return amd_f17h_perfmon_event_map[hw_event]; + if (cpu_feature_enabled(X86_FEATURE_ZEN2) || boot_cpu_data.x86 >= 0x19) + return amd_zen2_perfmon_event_map[hw_event]; + + if (cpu_feature_enabled(X86_FEATURE_ZEN1)) + return amd_zen1_perfmon_event_map[hw_event]; return amd_perfmon_event_map[hw_event]; }

8 months, 4 weeks

1
0
0 0

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