From 0cce06ba859a515bd06224085d3addb870608b6d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 25 Apr 2023 17:03:13 +0200 Subject: debugobjects,locking: Annotate debug_object_fill_pool() wait type violation There is an explicit wait-type violation in debug_object_fill_pool() for PREEMPT_RT=n kernels which allows them to more easily fill the object pool and reduce the chance of allocation failures. Lockdep's wait-type checks are designed to check the PREEMPT_RT locking rules even for PREEMPT_RT=n kernels and object to this, so create a lockdep annotation to allow this to stand. Specifically, create a 'lock' type that overrides the inner wait-type while it is held -- allowing one to temporarily raise it, such that the violation is hidden. Reported-by: Vlastimil Babka Reported-by: Qi Zheng Signed-off-by: Peter Zijlstra (Intel) Tested-by: Qi Zheng Link: https://lkml.kernel.org/r/20230429100614.GA1489784@hirez.programming.kicks-ass.net --- include/linux/lockdep.h | 14 ++++++++++++++ include/linux/lockdep_types.h | 1 + 2 files changed, 15 insertions(+) (limited to 'include') diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 1023f349af71..a3329fb49b33 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -339,6 +339,16 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); #define lockdep_repin_lock(l,c) lock_repin_lock(&(l)->dep_map, (c)) #define lockdep_unpin_lock(l,c) lock_unpin_lock(&(l)->dep_map, (c)) +/* + * Must use lock_map_aquire_try() with override maps to avoid + * lockdep thinking they participate in the block chain. + */ +#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \ + struct lockdep_map _name = { \ + .name = #_name "-wait-type-override", \ + .wait_type_inner = _wait_type, \ + .lock_type = LD_LOCK_WAIT_OVERRIDE, } + #else /* !CONFIG_LOCKDEP */ static inline void lockdep_init_task(struct task_struct *task) @@ -427,6 +437,9 @@ extern int lockdep_is_held(const void *); #define lockdep_repin_lock(l, c) do { (void)(l); (void)(c); } while (0) #define lockdep_unpin_lock(l, c) do { (void)(l); (void)(c); } while (0) +#define DEFINE_WAIT_OVERRIDE_MAP(_name, _wait_type) \ + struct lockdep_map __maybe_unused _name = {} + #endif /* !LOCKDEP */ enum xhlock_context_t { @@ -551,6 +564,7 @@ do { \ #define rwsem_release(l, i) lock_release(l, i) #define lock_map_acquire(l) lock_acquire_exclusive(l, 0, 0, NULL, _THIS_IP_) +#define lock_map_acquire_try(l) lock_acquire_exclusive(l, 0, 1, NULL, _THIS_IP_) #define lock_map_acquire_read(l) lock_acquire_shared_recursive(l, 0, 0, NULL, _THIS_IP_) #define lock_map_acquire_tryread(l) lock_acquire_shared_recursive(l, 0, 1, NULL, _THIS_IP_) #define lock_map_release(l) lock_release(l, _THIS_IP_) diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h index d22430840b53..59f4fb1626ea 100644 --- a/include/linux/lockdep_types.h +++ b/include/linux/lockdep_types.h @@ -33,6 +33,7 @@ enum lockdep_wait_type { enum lockdep_lock_type { LD_LOCK_NORMAL = 0, /* normal, catch all */ LD_LOCK_PERCPU, /* percpu */ + LD_LOCK_WAIT_OVERRIDE, /* annotation */ LD_LOCK_MAX, }; -- cgit v1.2.3 From 19b8766459c41c6f318f8a548cc1c66dffd18363 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Thu, 20 Apr 2023 16:06:03 +0100 Subject: firmware: arm_ffa: Fix FFA device names for logical partitions Each physical partition can provide multiple services each with UUID. Each such service can be presented as logical partition with a unique combination of VM ID and UUID. The number of distinct UUID in a system will be less than or equal to the number of logical partitions. However, currently it fails to register more than one logical partition or service within a physical partition as the device name contains only VM ID while both VM ID and UUID are maintained in the partition information. The kernel complains with the below message: | sysfs: cannot create duplicate filename '/devices/arm-ffa-8001' | CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc7 #8 | Hardware name: FVP Base RevC (DT) | Call trace: | dump_backtrace+0xf8/0x118 | show_stack+0x18/0x24 | dump_stack_lvl+0x50/0x68 | dump_stack+0x18/0x24 | sysfs_create_dir_ns+0xe0/0x13c | kobject_add_internal+0x220/0x3d4 | kobject_add+0x94/0x100 | device_add+0x144/0x5d8 | device_register+0x20/0x30 | ffa_device_register+0x88/0xd8 | ffa_setup_partitions+0x108/0x1b8 | ffa_init+0x2ec/0x3a4 | do_one_initcall+0xcc/0x240 | do_initcall_level+0x8c/0xac | do_initcalls+0x54/0x94 | do_basic_setup+0x1c/0x28 | kernel_init_freeable+0x100/0x16c | kernel_init+0x20/0x1a0 | ret_from_fork+0x10/0x20 | kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to | register things with the same name in the same directory. | arm_ffa arm-ffa: unable to register device arm-ffa-8001 err=-17 | ARM FF-A: ffa_setup_partitions: failed to register partition ID 0x8001 By virtue of being random enough to avoid collisions when generated in a distributed system, there is no way to compress UUID keys to the number of bits required to identify each. We can eliminate '-' in the name but it is not worth eliminating 4 bytes and add unnecessary logic for doing that. Also v1.0 doesn't provide the UUID of the partitions which makes it hard to use the same for the device name. So to keep it simple, let us alloc an ID using ida_alloc() and append the same to "arm-ffa" to make up a unique device name. Also stash the id value in ffa_dev to help freeing the ID later when the device is destroyed. Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Reported-by: Lucian Paul-Trifu Link: https://lore.kernel.org/r/20230419-ffa_fixes_6-4-v2-3-d9108e43a176@arm.com Signed-off-by: Sudeep Holla --- include/linux/arm_ffa.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h index c87aeecaa9b2..583fe3b49a49 100644 --- a/include/linux/arm_ffa.h +++ b/include/linux/arm_ffa.h @@ -96,6 +96,7 @@ /* FFA Bus/Device/Driver related */ struct ffa_device { + u32 id; int vm_id; bool mode_32bit; uuid_t uuid; -- cgit v1.2.3 From f7ba52f302fdc392e0047f38e50841483d997144 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 18 Apr 2023 14:49:25 -0700 Subject: vmlinux.lds.h: Discard .note.gnu.property section MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When tooling reads ELF notes, it assumes each note entry is aligned to the value listed in the .note section header's sh_addralign field. The kernel-created ELF notes in the .note.Linux and .note.Xen sections are aligned to 4 bytes. This causes the toolchain to set those sections' sh_addralign values to 4. On the other hand, the GCC-created .note.gnu.property section has an sh_addralign value of 8 for some reason, despite being based on struct Elf32_Nhdr which only needs 4-byte alignment. When the mismatched input sections get linked together into the vmlinux .notes output section, the higher alignment "wins", resulting in an sh_addralign of 8, which confuses tooling. For example: $ readelf -n .tmp_vmlinux.btf ... readelf: .tmp_vmlinux.btf: Warning: note with invalid namesz and/or descsz found at offset 0x170 readelf: .tmp_vmlinux.btf: Warning: type: 0x4, namesize: 0x006e6558, descsize: 0x00008801, alignment: 8 In this case readelf thinks there's alignment padding where there is none, so it starts reading an ELF note in the middle. With newer toolchains (e.g., latest Fedora Rawhide), a similar mismatch triggers a build failure when combined with CONFIG_X86_KERNEL_IBT: btf_encoder__encode: btf__dedup failed! Failed to encode BTF libbpf: failed to find '.BTF' ELF section in vmlinux FAILED: load BTF from vmlinux: No data available make[1]: *** [scripts/Makefile.vmlinux:35: vmlinux] Error 255 This latter error was caused by pahole crashing when it encountered the corrupt .notes section. This crash has been fixed in dwarves version 1.25. As Tianyi Liu describes: "Pahole reads .notes to look for LINUX_ELFNOTE_BUILD_LTO. When LTO is enabled, pahole needs to call cus__merge_and_process_cu to merge compile units, at which point there should only be one unspecified type (used to represent some compilation information) in the global context. However, when the kernel is compiled without LTO, if pahole calls cus__merge_and_process_cu due to alignment issues with notes, multiple unspecified types may appear after merging the cus, and older versions of pahole only support up to one. This is why pahole 1.24 crashes, while newer versions support multiple. However, the latest version of pahole still does not solve the problem of incorrect LTO recognition, so compiling the kernel may be slower than normal." Even with the newer pahole, the note section misaligment issue still exists and pahole is misinterpreting the LTO note. Fix it by discarding the .note.gnu.property section. While GNU properties are important for user space (and VDSO), they don't seem to have any use for vmlinux. (In fact, they're already getting (inadvertently) stripped from vmlinux when CONFIG_DEBUG_INFO_BTF is enabled. The BTF data is extracted from vmlinux.o with "objcopy --only-section=.BTF" into .btf.vmlinux.bin.o. That file doesn't have .note.gnu.property, so when it gets modified and linked back into the main object, the linker automatically strips it (see "How GNU properties are merged" in the ld man page).) Reported-by: Daniel Xu Link: https://lkml.kernel.org/bpf/57830c30-cd77-40cf-9cd1-3bb608aa602e@app.fastmail.com Debugged-by: Tianyi Liu Suggested-by: Joan Bruguera Micó Link: https://lore.kernel.org/r/20230418214925.ay3jpf2zhw75kgmd@treble Signed-off-by: Josh Poimboeuf --- include/asm-generic/vmlinux.lds.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index d1f57e4868ed..cebdf1ca415d 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -891,9 +891,16 @@ /* * Discard .note.GNU-stack, which is emitted as PROGBITS by the compiler. * Otherwise, the type of .notes section would become PROGBITS instead of NOTES. + * + * Also, discard .note.gnu.property, otherwise it forces the notes section to + * be 8-byte aligned which causes alignment mismatches with the kernel's custom + * 4-byte aligned notes. */ #define NOTES \ - /DISCARD/ : { *(.note.GNU-stack) } \ + /DISCARD/ : { \ + *(.note.GNU-stack) \ + *(.note.gnu.property) \ + } \ .notes : AT(ADDR(.notes) - LOAD_OFFSET) { \ BOUNDED_SECTION_BY(.note.*, _notes) \ } NOTES_HEADERS \ -- cgit v1.2.3 From f15afbd34d8fadbd375f1212e97837e32bc170cc Mon Sep 17 00:00:00 2001 From: Hao Ge Date: Mon, 24 Apr 2023 13:18:35 +0800 Subject: fs: fix undefined behavior in bit shift for SB_NOUSER Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. It was spotted by UBSAN. So let's just fix this by using the BIT() helper for all SB_* flags. Fixes: e462ec50cb5f ("VFS: Differentiate mount flags (MS_*) from internal superblock flags") Signed-off-by: Hao Ge Message-Id: <20230424051835.374204-1-gehao@kylinos.cn> [brauner@kernel.org: use BIT() for all SB_* flags] Signed-off-by: Christian Brauner --- include/linux/fs.h | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 21a981680856..133f0640fb24 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1076,29 +1076,29 @@ extern int send_sigurg(struct fown_struct *fown); * sb->s_flags. Note that these mirror the equivalent MS_* flags where * represented in both. */ -#define SB_RDONLY 1 /* Mount read-only */ -#define SB_NOSUID 2 /* Ignore suid and sgid bits */ -#define SB_NODEV 4 /* Disallow access to device special files */ -#define SB_NOEXEC 8 /* Disallow program execution */ -#define SB_SYNCHRONOUS 16 /* Writes are synced at once */ -#define SB_MANDLOCK 64 /* Allow mandatory locks on an FS */ -#define SB_DIRSYNC 128 /* Directory modifications are synchronous */ -#define SB_NOATIME 1024 /* Do not update access times. */ -#define SB_NODIRATIME 2048 /* Do not update directory access times */ -#define SB_SILENT 32768 -#define SB_POSIXACL (1<<16) /* VFS does not apply the umask */ -#define SB_INLINECRYPT (1<<17) /* Use blk-crypto for encrypted files */ -#define SB_KERNMOUNT (1<<22) /* this is a kern_mount call */ -#define SB_I_VERSION (1<<23) /* Update inode I_version field */ -#define SB_LAZYTIME (1<<25) /* Update the on-disk [acm]times lazily */ +#define SB_RDONLY BIT(0) /* Mount read-only */ +#define SB_NOSUID BIT(1) /* Ignore suid and sgid bits */ +#define SB_NODEV BIT(2) /* Disallow access to device special files */ +#define SB_NOEXEC BIT(3) /* Disallow program execution */ +#define SB_SYNCHRONOUS BIT(4) /* Writes are synced at once */ +#define SB_MANDLOCK BIT(6) /* Allow mandatory locks on an FS */ +#define SB_DIRSYNC BIT(7) /* Directory modifications are synchronous */ +#define SB_NOATIME BIT(10) /* Do not update access times. */ +#define SB_NODIRATIME BIT(11) /* Do not update directory access times */ +#define SB_SILENT BIT(15) +#define SB_POSIXACL BIT(16) /* VFS does not apply the umask */ +#define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */ +#define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */ +#define SB_I_VERSION BIT(23) /* Update inode I_version field */ +#define SB_LAZYTIME BIT(25) /* Update the on-disk [acm]times lazily */ /* These sb flags are internal to the kernel */ -#define SB_SUBMOUNT (1<<26) -#define SB_FORCE (1<<27) -#define SB_NOSEC (1<<28) -#define SB_BORN (1<<29) -#define SB_ACTIVE (1<<30) -#define SB_NOUSER (1<<31) +#define SB_SUBMOUNT BIT(26) +#define SB_FORCE BIT(27) +#define SB_NOSEC BIT(28) +#define SB_BORN BIT(29) +#define SB_ACTIVE BIT(30) +#define SB_NOUSER BIT(31) /* These flags relate to encoding and casefolding */ #define SB_ENC_STRICT_MODE_FL (1 << 0) -- cgit v1.2.3 From c21f11d182c2180d8b90eaff84f574cfa845b250 Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Fri, 19 May 2023 10:07:33 +0100 Subject: drm: fix drmm_mutex_init() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In mutex_init() lockdep identifies a lock by defining a special static key for each lock class. However if we wrap the macro in a function, like in drmm_mutex_init(), we end up generating: int drmm_mutex_init(struct drm_device *dev, struct mutex *lock) { static struct lock_class_key __key; __mutex_init((lock), "lock", &__key); .... } The static __key here is what lockdep uses to identify the lock class, however since this is just a normal function the key here will be created once, where all callers then use the same key. In effect the mutex->depmap.key will be the same pointer for different drmm_mutex_init() callers. This then results in impossible lockdep splats since lockdep thinks completely unrelated locks are the same lock class. To fix this turn drmm_mutex_init() into a macro such that it generates a different "static struct lock_class_key __key" for each invocation, which looks to be inline with what mutex_init() wants. v2: - Revamp the commit message with clearer explanation of the issue. - Rather export __drmm_mutex_release() than static inline. Reported-by: Thomas Hellström Reported-by: Sarah Walker Fixes: e13f13e039dc ("drm: Add DRM-managed mutex_init()") Cc: Stanislaw Gruszka Cc: Boris Brezillon Cc: Thomas Zimmermann Cc: Jocelyn Falempe Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Signed-off-by: Matthew Auld Reviewed-by: Boris Brezillon Reviewed-by: Stanislaw Gruszka Reviewed-by: Lucas De Marchi Acked-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20230519090733.489019-1-matthew.auld@intel.com --- include/drm/drm_managed.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h index 359883942612..ad08f834af40 100644 --- a/include/drm/drm_managed.h +++ b/include/drm/drm_managed.h @@ -105,6 +105,22 @@ char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp); void drmm_kfree(struct drm_device *dev, void *data); -int drmm_mutex_init(struct drm_device *dev, struct mutex *lock); +void __drmm_mutex_release(struct drm_device *dev, void *res); + +/** + * drmm_mutex_init - &drm_device-managed mutex_init() + * @dev: DRM device + * @lock: lock to be initialized + * + * Returns: + * 0 on success, or a negative errno code otherwise. + * + * This is a &drm_device-managed version of mutex_init(). The initialized + * lock is automatically destroyed on the final drm_dev_put(). + */ +#define drmm_mutex_init(dev, lock) ({ \ + mutex_init(lock); \ + drmm_add_action_or_reset(dev, __drmm_mutex_release, lock); \ +}) \ #endif -- cgit v1.2.3 From dcbd1ac2668b5fa02069ea96d581ca3f70a7543c Mon Sep 17 00:00:00 2001 From: Beau Belgrave Date: Fri, 19 May 2023 16:07:40 -0700 Subject: tracing/user_events: Rename link fields for clarity Currently most list_head fields of various structs within user_events are simply named link. This causes folks to keep additional context in their head when working with the code, which can be confusing. Instead of using link, describe what the actual link is, for example: list_del_rcu(&mm->link); Changes into: list_del_rcu(&mm->mms_link); The reader now is given a hint the link is to the mms global list instead of having to remember or spot check within the code. Link: https://lkml.kernel.org/r/20230519230741.669-4-beaub@linux.microsoft.com Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wicngggxVpbnrYHjRTwGE0WYscPRM+L2HO2BF8ia1EXgQ@mail.gmail.com/ Suggested-by: Linus Torvalds Signed-off-by: Beau Belgrave Signed-off-by: Steven Rostedt (Google) --- include/linux/user_events.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/user_events.h b/include/linux/user_events.h index 2847f5a18a86..17d452b389de 100644 --- a/include/linux/user_events.h +++ b/include/linux/user_events.h @@ -17,7 +17,7 @@ #ifdef CONFIG_USER_EVENTS struct user_event_mm { - struct list_head link; + struct list_head mms_link; struct list_head enablers; struct mm_struct *mm; struct user_event_mm *next; -- cgit v1.2.3 From ff9e1632d69e596d8ca256deb07433a8f3565038 Mon Sep 17 00:00:00 2001 From: Beau Belgrave Date: Fri, 19 May 2023 16:07:41 -0700 Subject: tracing/user_events: Document user_event_mm one-shot list usage During 6.4 development it became clear that the one-shot list used by the user_event_mm's next field was confusing to others. It is not clear how this list is protected or what the next field usage is for unless you are familiar with the code. Add comments into the user_event_mm struct indicating lock requirement and usage. Also document how and why this approach was used via comments in both user_event_enabler_update() and user_event_mm_get_all() and the rules to properly use it. Link: https://lkml.kernel.org/r/20230519230741.669-5-beaub@linux.microsoft.com Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wicngggxVpbnrYHjRTwGE0WYscPRM+L2HO2BF8ia1EXgQ@mail.gmail.com/ Suggested-by: Linus Torvalds Signed-off-by: Beau Belgrave Signed-off-by: Steven Rostedt (Google) --- include/linux/user_events.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/user_events.h b/include/linux/user_events.h index 17d452b389de..8afa8c3a0973 100644 --- a/include/linux/user_events.h +++ b/include/linux/user_events.h @@ -20,6 +20,7 @@ struct user_event_mm { struct list_head mms_link; struct list_head enablers; struct mm_struct *mm; + /* Used for one-shot lists, protected by event_mutex */ struct user_event_mm *next; refcount_t refcnt; refcount_t tasks; -- cgit v1.2.3 From 4b512860bdbdddcf41467ebd394f27cb8dfb528c Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 23 May 2023 23:09:13 -0400 Subject: tracing: Rename stacktrace field to common_stacktrace The histogram and synthetic events can use a pseudo event called "stacktrace" that will create a stacktrace at the time of the event and use it just like it was a normal field. We have other pseudo events such as "common_cpu" and "common_timestamp". To stay consistent with that, convert "stacktrace" to "common_stacktrace". As this was used in older kernels, to keep backward compatibility, this will act just like "common_cpu" did with "cpu". That is, "cpu" will be the same as "common_cpu" unless the event has a "cpu" field. In which case, the event's field is used. The same is true with "stacktrace". Also update the documentation to reflect this change. Link: https://lore.kernel.org/linux-trace-kernel/20230523230913.6860e28d@rorschach.local.home Cc: Masami Hiramatsu Cc: Tom Zanussi Cc: Mark Rutland Signed-off-by: Steven Rostedt (Google) --- include/linux/trace_events.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 0e373222a6df..7c4a0b72334e 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -806,6 +806,7 @@ enum { FILTER_TRACE_FN, FILTER_COMM, FILTER_CPU, + FILTER_STACKTRACE, }; extern int trace_event_raw_init(struct trace_event_call *call); -- cgit v1.2.3 From 335b4223466dd75f9f3ea4918187afbadd22e5c8 Mon Sep 17 00:00:00 2001 From: Maximilian Heyne Date: Wed, 3 May 2023 13:16:53 +0000 Subject: x86/pci/xen: populate MSI sysfs entries Commit bf5e758f02fc ("genirq/msi: Simplify sysfs handling") reworked the creation of sysfs entries for MSI IRQs. The creation used to be in msi_domain_alloc_irqs_descs_locked after calling ops->domain_alloc_irqs. Then it moved into __msi_domain_alloc_irqs which is an implementation of domain_alloc_irqs. However, Xen comes with the only other implementation of domain_alloc_irqs and hence doesn't run the sysfs population code anymore. Commit 6c796996ee70 ("x86/pci/xen: Fixup fallout from the PCI/MSI overhaul") set the flag MSI_FLAG_DEV_SYSFS for the xen msi_domain_info but that doesn't actually have an effect because Xen uses it's own domain_alloc_irqs implementation. Fix this by making use of the fallback functions for sysfs population. Fixes: bf5e758f02fc ("genirq/msi: Simplify sysfs handling") Signed-off-by: Maximilian Heyne Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20230503131656.15928-1-mheyne@amazon.de Signed-off-by: Juergen Gross --- include/linux/msi.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/msi.h b/include/linux/msi.h index cdb14a1ef268..a50ea79522f8 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -383,6 +383,13 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc); void arch_teardown_msi_irq(unsigned int irq); int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type); void arch_teardown_msi_irqs(struct pci_dev *dev); +#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */ + +/* + * Xen uses non-default msi_domain_ops and hence needs a way to populate sysfs + * entries of MSI IRQs. + */ +#if defined(CONFIG_PCI_XEN) || defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) #ifdef CONFIG_SYSFS int msi_device_populate_sysfs(struct device *dev); void msi_device_destroy_sysfs(struct device *dev); @@ -390,7 +397,7 @@ void msi_device_destroy_sysfs(struct device *dev); static inline int msi_device_populate_sysfs(struct device *dev) { return 0; } static inline void msi_device_destroy_sysfs(struct device *dev) { } #endif /* !CONFIG_SYSFS */ -#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */ +#endif /* CONFIG_PCI_XEN || CONFIG_PCI_MSI_ARCH_FALLBACKS */ /* * The restore hook is still available even for fully irq domain based -- cgit v1.2.3 From 1db1f21caebbb1b6e9b1e7657df613616be3fb49 Mon Sep 17 00:00:00 2001 From: Dragos Tatulea Date: Thu, 13 Apr 2023 15:48:30 +0300 Subject: net/mlx5e: Use query_special_contexts cmd only once per mdev Don't query the firmware so many times (num rqs * num wqes * wqe frags) because it slows down linearly the interface creation time when the product is larger. Do it only once per mdev and store the result in mlx5e_param. Due to helper function being called from different files, move it to an appropriate location. Rename the function with a proper prefix and add a small cleanup. This fix applies only for legacy rq. Fixes: 1b1e4868836a ("net/mlx5e: Use query_special_contexts for mkeys") Signed-off-by: Dragos Tatulea Reviewed-by: Or Har-Toov Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed --- include/linux/mlx5/driver.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index a4c4f737f9c1..94d2be5848ae 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -1093,6 +1093,7 @@ void mlx5_cmdif_debugfs_cleanup(struct mlx5_core_dev *dev); int mlx5_core_create_psv(struct mlx5_core_dev *dev, u32 pdn, int npsvs, u32 *sig_index); int mlx5_core_destroy_psv(struct mlx5_core_dev *dev, int psv_num); +__be32 mlx5_core_get_terminate_scatter_list_mkey(struct mlx5_core_dev *dev); void mlx5_core_put_rsc(struct mlx5_core_rsc_common *common); int mlx5_query_odp_caps(struct mlx5_core_dev *dev, struct mlx5_odp_caps *odp_caps); -- cgit v1.2.3 From 9828ed3f695a138f7add89fa2a186ababceb8006 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 25 May 2023 09:32:25 -0700 Subject: module: error out early on concurrent load of the same module file It turns out that udev under certain circumstances will concurrently try to load the same modules over-and-over excessively. This isn't a kernel bug, but it ends up affecting the kernel, to the point that under certain circumstances we can fail to boot, because the kernel uses a lot of memory to read all the module data all at once. Note that it isn't a memory leak, it's just basically a thundering herd problem happening at bootup with a lot of CPUs, with the worst cases then being pretty bad. Admittedly the worst situations are somewhat contrived: lots and lots of CPUs, not a lot of memory, and KASAN enabled to make it all slower and as such (unintentionally) exacerbate the problem. Luis explains: [1] "My best assessment of the situation is that each CPU in udev ends up triggering a load of duplicate set of modules, not just one, but *a lot*. Not sure what heuristics udev uses to load a set of modules per CPU." Petr Pavlu chimes in: [2] "My understanding is that udev workers are forked. An initial kmod context is created by the main udevd process but no sharing happens after the fork. It means that the mentioned memory pool logic doesn't really kick in. Multiple parallel load requests come from multiple udev workers, for instance, each handling an udev event for one CPU device and making the exactly same requests as all others are doing at the same time. The optimization idea would be to recognize these duplicate requests at the udevd/kmod level and converge them" Note that module loading has tried to mitigate this issue before, see for example commit 064f4536d139 ("module: avoid allocation if module is already present and ready"), which has a few ASCII graphs on memory use due to this same issue. However, while that noticed that the module was already loaded, and exited with an error early before spending any more time on setting up the module, it didn't handle the case of multiple concurrent module loads all being active - but not complete - at the same time. Yes, one of them will eventually win the race and finalize its copy, and the others will then notice that the module already exists and error out, but while this all happens, we have tons of unnecessary concurrent work being done. Again, the real fix is for udev to not do that (maybe it should use threads instead of fork, and have actual shared data structures and not cause duplicate work). That real fix is apparently not trivial. But it turns out that the kernel already has a pretty good model for dealing with concurrent access to the same file: the i_writecount of the inode. In fact, the module loading already indirectly uses 'i_writecount' , because 'kernel_file_read()' will in fact do ret = deny_write_access(file); if (ret) return ret; ... allow_write_access(file); around the read of the file data. We do not allow concurrent writes to the file, and return -ETXTBUSY if the file was open for writing at the same time as the module data is loaded from it. And the solution to the reader concurrency problem is to simply extend this "no concurrent writers" logic to simply be "exclusive access". Note that "exclusive" in this context isn't really some absolute thing: it's only exclusion from writers and from other "special readers" that do this writer denial. So we simply introduce a variation of that "deny_write_access()" logic that not only denies write access, but also requires that this is the _only_ such access that denies write access. Which means that you can't start loading a module that is already being loaded as a module by somebody else, or you will get the same -ETXTBSY error that you would get if there were writers around. [ It also means that you can't try to load a currently executing executable as a module, for the same reason: executables do that same "deny_write_access()" thing, and that's obviously where the whole ETXTBSY logic traditionally came from. This is not a problem for kernel modules, since the set of normal executable files and kernel module files is entirely disjoint. ] This new function is called "exclusive_deny_write_access()", and the implementation is trivial, in that it's just an atomic decrement of i_writecount if it was 0 before. To use that new exclusivity check, all we then do is wrap the module loading with that exclusive_deny_write_access()() / allow_write_access() pair. The actual patch is a bit bigger than that, because we want to surround not just the "load file data" part, but the whole module setup, to get maximum exclusion. So this ends up splitting up "finit_module()" into a few helper functions to make it all very clear and legible. In Luis' test-case (bringing up 255 vcpu's in a virtual machine [3]), the "wasted vmalloc" space (ie module data read into a vmalloc'ed area in order to be loaded as a module, but then discarded because somebody else loaded the same module instead) dropped from 1.8GiB to 474kB. Yes, that's gigabytes to kilobytes. It doesn't drop completely to zero, because even with this change, you can still end up having completely serial pointless module loads, where one udev process has loaded a module fully (and thus the kernel has released that exclusive lock on the module file), and then another udev process tries to load the same module again. So while we cannot fully get rid of the fundamental bug in user space, we _can_ get rid of the excessive concurrent thundering herd effect. A couple of final side notes on this all: - This tweak only affects the "finit_module()" system call, which gives the kernel a file descriptor with the module data. You can also just feed the module data as raw data from user space with "init_module()" (note the lack of 'f' at the beginning), and obviously for that case we do _not_ have any "exclusive read" logic. So if you absolutely want to do things wrong in user space, and try to load the same module multiple times, and error out only later when the kernel ends up saying "you can't load the same module name twice", you can still do that. And in fact, some distros will do exactly that, because they will uncompress the kernel module data in user space before feeding it to the kernel (mainly because they haven't started using the new kernel side decompression yet). So this is not some absolute "you can't do concurrent loads of the same module". It's literally just a very simple heuristic that will catch it early in case you try to load the exact same module file at the same time, and in that case avoid a potentially nasty situation. - There is another user of "deny_write_access()": the verity code that enables fs-verity on a file (the FS_IOC_ENABLE_VERITY ioctl). If you use fs-verity and you care about verifying the kernel modules (which does make sense), you should do it *before* loading said kernel module. That may sound obvious, but now the implementation basically requires it. Because if you try to do it concurrently, the kernel may refuse to load the module file that is being set up by the fs-verity code. - This all will obviously mean that if you insist on loading the same module in parallel, only one module load will succeed, and the others will return with an error. That was true before too, but what is different is that the -ETXTBSY error can be returned *before* the success case of another process fully loading and instantiating the module. Again, that might sound obvious, and it is indeed the whole point of the whole change: we are much quicker to notice the whole "you're already in the process of loading this module". So it's very much intentional, but it does mean that if you just spray the kernel with "finit_module()", and expect that the module is immediately loaded afterwards without checking the return value, you are doing something horribly horribly wrong. I'd like to say that that would never happen, but the whole _reason_ for this commit is that udev is currently doing something horribly horribly wrong, so ... Link: https://lore.kernel.org/all/ZEGopJ8VAYnE7LQ2@bombadil.infradead.org/ [1] Link: https://lore.kernel.org/all/23bd0ce6-ef78-1cd8-1f21-0e706a00424a@suse.com/ [2] Link: https://lore.kernel.org/lkml/ZG%2Fa+nrt4%2FAAUi5z@bombadil.infradead.org/ [3] Cc: Greg Kroah-Hartman Cc: Lucas De Marchi Cc: Petr Pavlu Tested-by: Luis Chamberlain Signed-off-by: Linus Torvalds --- include/linux/fs.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 133f0640fb24..86b50271b4f7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2566,6 +2566,12 @@ static inline int deny_write_access(struct file *file) struct inode *inode = file_inode(file); return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; } +static inline int exclusive_deny_write_access(struct file *file) +{ + int old = 0; + struct inode *inode = file_inode(file); + return atomic_try_cmpxchg(&inode->i_writecount, &old, -1) ? 0 : -ETXTBSY; +} static inline void put_write_access(struct inode * inode) { atomic_dec(&inode->i_writecount); -- cgit v1.2.3 From ac2263b588dffd3a1efd7ed0b156ea6c5aea200d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 29 May 2023 06:40:33 -0400 Subject: Revert "module: error out early on concurrent load of the same module file" This reverts commit 9828ed3f695a138f7add89fa2a186ababceb8006. Sadly, it does seem to cause failures to load modules. Johan Hovold reports: "This change breaks module loading during boot on the Lenovo Thinkpad X13s (aarch64). Specifically it results in indefinite probe deferral of the display and USB (ethernet) which makes it a pain to debug. Typing in the dark to acquire some logs reveals that other modules are missing as well" Since this was applied late as a "let's try this", I'm reverting it asap, and we can try to figure out what goes wrong later. The excessive parallel module loading problem is annoying, but not noticeable in normal situations, and this was only meant as an optimistic workaround for a user-space bug. One possible solution may be to do the optimistic exclusive open first, and then use a lock to serialize loading if that fails. Reported-by: Johan Hovold Link: https://lore.kernel.org/lkml/ZHRpH-JXAxA6DnzR@hovoldconsulting.com/ Signed-off-by: Linus Torvalds --- include/linux/fs.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 86b50271b4f7..133f0640fb24 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2566,12 +2566,6 @@ static inline int deny_write_access(struct file *file) struct inode *inode = file_inode(file); return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; } -static inline int exclusive_deny_write_access(struct file *file) -{ - int old = 0; - struct inode *inode = file_inode(file); - return atomic_try_cmpxchg(&inode->i_writecount, &old, -1) ? 0 : -ETXTBSY; -} static inline void put_write_access(struct inode * inode) { atomic_dec(&inode->i_writecount); -- cgit v1.2.3 From 4faeee0cf8a5d88d63cdbc3bab124fb0e6aed08c Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 26 May 2023 16:34:58 +0000 Subject: tcp: deny tcp_disconnect() when threads are waiting Historically connect(AF_UNSPEC) has been abused by syzkaller and other fuzzers to trigger various bugs. A recent one triggers a divide-by-zero [1], and Paolo Abeni was able to diagnose the issue. tcp_recvmsg_locked() has tests about sk_state being not TCP_LISTEN and TCP REPAIR mode being not used. Then later if socket lock is released in sk_wait_data(), another thread can call connect(AF_UNSPEC), then make this socket a TCP listener. When recvmsg() is resumed, it can eventually call tcp_cleanup_rbuf() and attempt a divide by 0 in tcp_rcv_space_adjust() [1] This patch adds a new socket field, counting number of threads blocked in sk_wait_event() and inet_wait_for_connect(). If this counter is not zero, tcp_disconnect() returns an error. This patch adds code in blocking socket system calls, thus should not hurt performance of non blocking ones. Note that we probably could revert commit 499350a5a6e7 ("tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0") to restore original tcpi_rcv_mss meaning (was 0 if no payload was ever received on a socket) [1] divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13832 Comm: syz-executor.5 Not tainted 6.3.0-rc4-syzkaller-00224-g00c7b5f4ddc5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:tcp_rcv_space_adjust+0x36e/0x9d0 net/ipv4/tcp_input.c:740 Code: 00 00 00 00 fc ff df 4c 89 64 24 48 8b 44 24 04 44 89 f9 41 81 c7 80 03 00 00 c1 e1 04 44 29 f0 48 63 c9 48 01 e9 48 0f af c1 <49> f7 f6 48 8d 04 41 48 89 44 24 40 48 8b 44 24 30 48 c1 e8 03 48 RSP: 0018:ffffc900033af660 EFLAGS: 00010206 RAX: 4a66b76cbade2c48 RBX: ffff888076640cc0 RCX: 00000000c334e4ac RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000001 RBP: 00000000c324e86c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880766417f8 R13: ffff888028fbb980 R14: 0000000000000000 R15: 0000000000010344 FS: 00007f5bffbfe700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32f25000 CR3: 000000007ced0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_recvmsg_locked+0x100e/0x22e0 net/ipv4/tcp.c:2616 tcp_recvmsg+0x117/0x620 net/ipv4/tcp.c:2681 inet6_recvmsg+0x114/0x640 net/ipv6/af_inet6.c:670 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg+0xe2/0x160 net/socket.c:1038 ____sys_recvmsg+0x210/0x5a0 net/socket.c:2720 ___sys_recvmsg+0xf2/0x180 net/socket.c:2762 do_recvmmsg+0x25e/0x6e0 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5c0108c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5bffbfe168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f5c011ac050 RCX: 00007f5c0108c0f9 RDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000003 RBP: 00007f5c010e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5c012cfb1f R14: 00007f5bffbfe300 R15: 0000000000022000 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot Reported-by: Paolo Abeni Diagnosed-by: Paolo Abeni Signed-off-by: Eric Dumazet Tested-by: Paolo Abeni Link: https://lore.kernel.org/r/20230526163458.2880232-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/sock.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/net/sock.h b/include/net/sock.h index 656ea89f60ff..b418425d7230 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -336,6 +336,7 @@ struct sk_filter; * @sk_cgrp_data: cgroup data for this cgroup * @sk_memcg: this socket's memory cgroup association * @sk_write_pending: a write to stream socket waits to start + * @sk_wait_pending: number of threads blocked on this socket * @sk_state_change: callback to indicate change in the state of the sock * @sk_data_ready: callback to indicate there is data to be processed * @sk_write_space: callback to indicate there is bf sending space available @@ -428,6 +429,7 @@ struct sock { unsigned int sk_napi_id; #endif int sk_rcvbuf; + int sk_wait_pending; struct sk_filter __rcu *sk_filter; union { @@ -1174,6 +1176,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk) #define sk_wait_event(__sk, __timeo, __condition, __wait) \ ({ int __rc; \ + __sk->sk_wait_pending++; \ release_sock(__sk); \ __rc = __condition; \ if (!__rc) { \ @@ -1183,6 +1186,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk) } \ sched_annotate_sleep(); \ lock_sock(__sk); \ + __sk->sk_wait_pending--; \ __rc = __condition; \ __rc; \ }) -- cgit v1.2.3 From 1919b39fc6eabb9a6f9a51706ff6d03865f5df29 Mon Sep 17 00:00:00 2001 From: Haiyang Zhang Date: Fri, 26 May 2023 08:38:57 -0700 Subject: net: mana: Fix perf regression: remove rx_cqes, tx_cqes counters The apc->eth_stats.rx_cqes is one per NIC (vport), and it's on the frequent and parallel code path of all queues. So, r/w into this single shared variable by many threads on different CPUs creates a lot caching and memory overhead, hence perf regression. And, it's not accurate due to the high volume concurrent r/w. For example, a workload is iperf with 128 threads, and with RPS enabled. We saw perf regression of 25% with the previous patch adding the counters. And this patch eliminates the regression. Since the error path of mana_poll_rx_cq() already has warnings, so keeping the counter and convert it to a per-queue variable is not necessary. So, just remove this counter from this high frequency code path. Also, remove the tx_cqes counter for the same reason. We have warnings & other counters for errors on that path, and don't need to count every normal cqe processing. Cc: stable@vger.kernel.org Fixes: bd7fc6e1957c ("net: mana: Add new MANA VF performance counters for easier troubleshooting") Signed-off-by: Haiyang Zhang Reviewed-by: Horatiu Vultur Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/1685115537-31675-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Paolo Abeni --- include/net/mana/mana.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include') diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index cd386aa7c7cc..9eef19972845 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -347,10 +347,8 @@ struct mana_tx_qp { struct mana_ethtool_stats { u64 stop_queue; u64 wake_queue; - u64 tx_cqes; u64 tx_cqe_err; u64 tx_cqe_unknown_type; - u64 rx_cqes; u64 rx_coalesced_err; u64 rx_cqe_unknown_type; }; -- cgit v1.2.3 From 30c6f0bf9579debce27e45fac34fdc97e46acacc Mon Sep 17 00:00:00 2001 From: fuyuanli Date: Wed, 31 May 2023 16:01:50 +0800 Subject: tcp: fix mishandling when the sack compression is deferred. In this patch, we mainly try to handle sending a compressed ack correctly if it's deferred. Here are more details in the old logic: When sack compression is triggered in the tcp_compressed_ack_kick(), if the sock is owned by user, it will set TCP_DELACK_TIMER_DEFERRED and then defer to the release cb phrase. Later once user releases the sock, tcp_delack_timer_handler() should send a ack as expected, which, however, cannot happen due to lack of ICSK_ACK_TIMER flag. Therefore, the receiver would not sent an ack until the sender's retransmission timeout. It definitely increases unnecessary latency. Fixes: 5d9f4262b7ea ("tcp: add SACK compression") Suggested-by: Eric Dumazet Signed-off-by: fuyuanli Signed-off-by: Jason Xing Link: https://lore.kernel.org/netdev/20230529113804.GA20300@didi-ThinkCentre-M920t-N000/ Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20230531080150.GA20424@didi-ThinkCentre-M920t-N000 Signed-off-by: Paolo Abeni --- include/net/tcp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/net/tcp.h b/include/net/tcp.h index 18a038d16434..5066e4586cf0 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -632,6 +632,7 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb); void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); void tcp_fin(struct sock *sk); void tcp_check_space(struct sock *sk); +void tcp_sack_compress_send_ack(struct sock *sk); /* tcp_timer.c */ void tcp_init_xmit_timers(struct sock *); -- cgit v1.2.3 From 4420528254153189c70b6267593e445dc8654e37 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 29 May 2023 12:52:07 -0600 Subject: firewire: Replace zero-length array with flexible-array member MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: sound/firewire/amdtp-stream.c: In function ‘build_it_pkt_header’: sound/firewire/amdtp-stream.c:694:17: warning: ‘generate_cip_header’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] 694 | generate_cip_header(s, cip_header, data_block_counter, syt); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/firewire/amdtp-stream.c:694:17: note: referencing argument 2 of type ‘__be32[2]’ {aka ‘unsigned int[2]’} sound/firewire/amdtp-stream.c:667:13: note: in a call to function ‘generate_cip_header’ 667 | static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2], | ^~~~~~~~~~~~~~~~~~~ This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/21 Link: https://github.com/KSPP/linux/issues/303 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/ZHT0V3SpvHyxCv5W@work Signed-off-by: Takashi Sakamoto --- include/linux/firewire.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/firewire.h b/include/linux/firewire.h index 1716c01c4e54..efb6e2cf2034 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -391,7 +391,7 @@ struct fw_iso_packet { u32 tag:2; /* tx: Tag in packet header */ u32 sy:4; /* tx: Sy in packet header */ u32 header_length:8; /* Length of immediate header */ - u32 header[0]; /* tx: Top of 1394 isoch. data_block */ + u32 header[]; /* tx: Top of 1394 isoch. data_block */ }; #define FW_ISO_CONTEXT_TRANSMIT 0 -- cgit v1.2.3 From f9010dbdce911ee1f1af1398a24b1f9f992e0080 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Thu, 1 Jun 2023 13:32:32 -0500 Subject: fork, vhost: Use CLONE_THREAD to fix freezer/ps regression When switching from kthreads to vhost_tasks two bugs were added: 1. The vhost worker tasks's now show up as processes so scripts doing ps or ps a would not incorrectly detect the vhost task as another process. 2. kthreads disabled freeze by setting PF_NOFREEZE, but vhost tasks's didn't disable or add support for them. To fix both bugs, this switches the vhost task to be thread in the process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that SIGKILL/STOP support is required because CLONE_THREAD requires CLONE_SIGHAND which requires those 2 signals to be supported. This is a modified version of the patch written by Mike Christie which was a modified version of patch originally written by Linus. Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER. Including ignoring signals, setting up the register state, and having get_signal return instead of calling do_group_exit. Tidied up the vhost_task abstraction so that the definition of vhost_task only needs to be visible inside of vhost_task.c. Making it easier to review the code and tell what needs to be done where. As part of this the main loop has been moved from vhost_worker into vhost_task_fn. vhost_worker now returns true if work was done. The main loop has been updated to call get_signal which handles SIGSTOP, freezing, and collects the message that tells the thread to exit as part of process exit. This collection clears __fatal_signal_pending. This collection is not guaranteed to clear signal_pending() so clear that explicitly so the schedule() sleeps. For now the vhost thread continues to exist and run work until the last file descriptor is closed and the release function is called as part of freeing struct file. To avoid hangs in the coredump rendezvous and when killing threads in a multi-threaded exec. The coredump code and de_thread have been modified to ignore vhost threads. Remvoing the special case for exec appears to require teaching vhost_dev_flush how to directly complete transactions in case the vhost thread is no longer running. Removing the special case for coredump rendezvous requires either the above fix needed for exec or moving the coredump rendezvous into get_signal. Fixes: 6e890c5d5021 ("vhost: use vhost_tasks for worker threads") Signed-off-by: Eric W. Biederman Co-developed-by: Mike Christie Signed-off-by: Mike Christie Acked-by: Michael S. Tsirkin Signed-off-by: Linus Torvalds --- include/linux/sched/task.h | 1 - include/linux/sched/vhost_task.h | 15 +++------------ 2 files changed, 3 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index 537cbf9a2ade..e0f5ac90a228 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -29,7 +29,6 @@ struct kernel_clone_args { u32 io_thread:1; u32 user_worker:1; u32 no_files:1; - u32 ignore_signals:1; unsigned long stack; unsigned long stack_size; unsigned long tls; diff --git a/include/linux/sched/vhost_task.h b/include/linux/sched/vhost_task.h index 6123c10b99cf..837a23624a66 100644 --- a/include/linux/sched/vhost_task.h +++ b/include/linux/sched/vhost_task.h @@ -2,22 +2,13 @@ #ifndef _LINUX_VHOST_TASK_H #define _LINUX_VHOST_TASK_H -#include -struct task_struct; +struct vhost_task; -struct vhost_task { - int (*fn)(void *data); - void *data; - struct completion exited; - unsigned long flags; - struct task_struct *task; -}; - -struct vhost_task *vhost_task_create(int (*fn)(void *), void *arg, +struct vhost_task *vhost_task_create(bool (*fn)(void *), void *arg, const char *name); void vhost_task_start(struct vhost_task *vtsk); void vhost_task_stop(struct vhost_task *vtsk); -bool vhost_task_should_stop(struct vhost_task *vtsk); +void vhost_task_wake(struct vhost_task *vtsk); #endif -- cgit v1.2.3