April 2024 - Linux-stable-mirror

[PATCH v3] rust: init: remove impl Zeroable for Infallible

by Laine Taffin Altman

A type is inhabited if at least one valid value of that type exists; a type is uninhabited if no valid values of that type exist. The terms "inhabited" and "uninhabited" in this sense originate in type theory, a branch of mathematics. In Rust, producing an invalid value of any type is immediate undefined behavior (UB); this includes via zeroing memory. Therefore, since an uninhabited type has no valid values, producing any values at all for it is UB. The Rust standard library type `core::convert::Infallible` is uninhabited, by virtue of having been declared as an enum with no cases, which always produces uninhabited types in Rust. The current kernel code allows this UB to be triggered, for example by code like: `pr_info!("{}”, Box::<core::convert::Infallible>::init(kernel::init::zeroed())?);` Thus, remove the implementation of `Zeroable` for `Infallible`, thereby avoiding the UB. Cc: stable(a)vger.kernel.org Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function") Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13 Signed-off-by: Laine Taffin Altman <alexanderaltman(a)me.com> Reviewed-by: Alice Ryhl <aliceryhl(a)google.com> Reviewed-by: Boqun Feng <boqun.feng(a)gmail.com> --- V2 -> V3: Email formatting correction. V1 -> V2: Added more documentation to the comment, with links; also added more details to the commit message. rust/kernel/init.rs | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs index 424257284d16..9353c9919fd4 100644 --- a/rust/kernel/init.rs +++ b/rust/kernel/init.rs @@ -1292,8 +1292,11 @@ macro_rules! impl_zeroable { i8, i16, i32, i64, i128, isize, f32, f64, - // SAFETY: These are ZSTs, there is nothing to zero. - {<T: ?Sized>} PhantomData<T>, core::marker::PhantomPinned, Infallible, (), + // SAFETY: These are inhabited ZSTs; there is nothing to zero and a valid value exists. + // Note: do not add uninhabited types (such as ! or Infallible) to this list; creating an instance of an uninhabited type is immediate undefined behavior. + // For more on uninhabited/empty types, consult The Rustonomicon: https://doc.rust-lang.org/stable/nomicon/exotic-sizes.html#empty-types + // The Rust Reference also has information on undefined behavior: https://doc.rust-lang.org/stable/reference/behavior-considered-undefined.ht… + {<T: ?Sized>} PhantomData<T>, core::marker::PhantomPinned, (), // SAFETY: Type is allowed to take any value, including all zeros. {<T>} MaybeUninit<T>, -- 2.44.0

1 year, 2 months

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[PATCH net 0/2] mptcp: fix fallback MIB counter and wrong var in selftests

by Matthieu Baerts (NGI0)

Here are two fixes related to MPTCP. The first patch fixes when the MPTcpExtMPCapableFallbackACK MIB counter is modified: it should only be incremented when a connection was using MPTCP options, but then a fallback to TCP has been done. This patch also checks the counter is not incremented by mistake during the connect selftests. This counter was wrongly incremented since its introduction in v5.7. The second patch fixes a wrong parsing of the 'dev' endpoint options in the selftests: the wrong variable was used. This option was not used before, but it is going to be soon. This issue is visible since v5.18. Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Davide Caratti (1): mptcp: don't account accept() of non-MPC client as fallback to TCP Geliang Tang (1): selftests: mptcp: join: fix dev in check_endpoint net/mptcp/protocol.c | 2 -- net/mptcp/subflow.c | 2 ++ tools/testing/selftests/net/mptcp/mptcp_connect.sh | 9 +++++++++ tools/testing/selftests/net/mptcp/mptcp_join.sh | 4 +++- 4 files changed, 14 insertions(+), 3 deletions(-) --- base-commit: 0ba80d96585662299d4ea4624043759ce9015421 change-id: 20240329-upstream-net-20240329-fallback-mib-b0fec9c6189b Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

1 year, 2 months

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[PATCH bluetooth] Bluetooth: Fix type of len in {l2cap,sco}_sock_getsockopt_old()

by Nathan Chancellor

After an innocuous optimization change in LLVM main (19.0.0), x86_64 allmodconfig (which enables CONFIG_KCSAN / -fsanitize=thread) fails to build due to the checks in check_copy_size(): In file included from net/bluetooth/sco.c:27: In file included from include/linux/module.h:13: In file included from include/linux/stat.h:19: In file included from include/linux/time.h:60: In file included from include/linux/time32.h:13: In file included from include/linux/timex.h:67: In file included from arch/x86/include/asm/timex.h:6: In file included from arch/x86/include/asm/tsc.h:10: In file included from arch/x86/include/asm/msr.h:15: In file included from include/linux/percpu.h:7: In file included from include/linux/smp.h:118: include/linux/thread_info.h:244:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small 244 | __bad_copy_from(); | ^ The same exact error occurs in l2cap_sock.c. The copy_to_user() statements that are failing come from l2cap_sock_getsockopt_old() and sco_sock_getsockopt_old(). This does not occur with GCC with or without KCSAN or Clang without KCSAN enabled. len is defined as an 'int' because it is assigned from '__user int *optlen'. However, it is clamped against the result of sizeof(), which has a type of 'size_t' ('unsigned long' for 64-bit platforms). This is done with min_t() because min() requires compatible types, which results in both len and the result of sizeof() being casted to 'unsigned int', meaning len changes signs and the result of sizeof() is truncated. From there, len is passed to copy_to_user(), which has a third parameter type of 'unsigned long', so it is widened and changes signs again. This excessive casting in combination with the KCSAN instrumentation causes LLVM to fail to eliminate the __bad_copy_from() call, failing the build. The official recommendation from LLVM developers is to consistently use long types for all size variables to avoid the unnecessary casting in the first place. Change the type of len to size_t in both l2cap_sock_getsockopt_old() and sco_sock_getsockopt_old(). This clears up the error while allowing min_t() to be replaced with min(), resulting in simpler code with no casts and fewer implicit conversions. While len is a different type than optlen now, it should result in no functional change because the result of sizeof() will clamp all values of optlen in the same manner as before. Cc: stable(a)vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2007 Link: https://github.com/llvm/llvm-project/issues/85647 Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- net/bluetooth/l2cap_sock.c | 7 ++++--- net/bluetooth/sco.c | 7 ++++--- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 4287aa6cc988..81193427bf05 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -439,7 +439,8 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, struct l2cap_chan *chan = l2cap_pi(sk)->chan; struct l2cap_options opts; struct l2cap_conninfo cinfo; - int len, err = 0; + int err = 0; + size_t len; u32 opt; BT_DBG("sk %p", sk); @@ -486,7 +487,7 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, BT_DBG("mode 0x%2.2x", chan->mode); - len = min_t(unsigned int, len, sizeof(opts)); + len = min(len, sizeof(opts)); if (copy_to_user(optval, (char *) &opts, len)) err = -EFAULT; @@ -536,7 +537,7 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, cinfo.hci_handle = chan->conn->hcon->handle; memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3); - len = min_t(unsigned int, len, sizeof(cinfo)); + len = min(len, sizeof(cinfo)); if (copy_to_user(optval, (char *) &cinfo, len)) err = -EFAULT; diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 43daf965a01e..9a72d7f1946c 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -967,7 +967,8 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname, struct sock *sk = sock->sk; struct sco_options opts; struct sco_conninfo cinfo; - int len, err = 0; + int err = 0; + size_t len; BT_DBG("sk %p", sk); @@ -989,7 +990,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname, BT_DBG("mtu %u", opts.mtu); - len = min_t(unsigned int, len, sizeof(opts)); + len = min(len, sizeof(opts)); if (copy_to_user(optval, (char *)&opts, len)) err = -EFAULT; @@ -1007,7 +1008,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname, cinfo.hci_handle = sco_pi(sk)->conn->hcon->handle; memcpy(cinfo.dev_class, sco_pi(sk)->conn->hcon->dev_class, 3); - len = min_t(unsigned int, len, sizeof(cinfo)); + len = min(len, sizeof(cinfo)); if (copy_to_user(optval, (char *)&cinfo, len)) err = -EFAULT; --- base-commit: 7835fcfd132eb88b87e8eb901f88436f63ab60f7 change-id: 20240401-bluetooth-fix-len-type-getsockopt_old-73c4a8e60444 Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

1 year, 2 months

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[PATCH] rust: macros: fix soundness issue in `module!` macro

by Benno Lossin

The `module!` macro creates glue code that are called by C to initialize the Rust modules using the `Module::init` function. Part of this glue code are the local functions `__init` and `__exit` that are used to initialize/destroy the Rust module. These functions are safe and also visible to the Rust mod in which the `module!` macro is invoked. This means that they can be called by other safe Rust code. But since they contain `unsafe` blocks that rely on only being called at the right time, this is a soundness issue. Wrap these generated functions inside of two private modules, this guarantees that the public functions cannot be called from the outside. Make the safe functions `unsafe` and add SAFETY comments. Cc: stable(a)vger.kernel.org Closes: https://github.com/Rust-for-Linux/linux/issues/629 Fixes: 1fbde52bde73 ("rust: add `macros` crate") Signed-off-by: Benno Lossin <benno.lossin(a)proton.me> --- This patch is best viewed with `git show --ignore-space-change`, since I also adjusted the indentation. rust/macros/module.rs | 198 ++++++++++++++++++++++++------------------ 1 file changed, 112 insertions(+), 86 deletions(-) diff --git a/rust/macros/module.rs b/rust/macros/module.rs index 27979e582e4b..16c4921a08f2 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -199,103 +199,129 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { /// Used by the printing macros, e.g. [`info!`]. const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; - /// The \"Rust loadable module\" mark. - // - // This may be best done another way later on, e.g. as a new modinfo - // key or a new section. For the moment, keep it simple. - #[cfg(MODULE)] - #[doc(hidden)] - #[used] - static __IS_RUST_MODULE: () = (); - - static mut __MOD: Option<{type_}> = None; - - // SAFETY: `__this_module` is constructed by the kernel at load time and will not be - // freed until the module is unloaded. - #[cfg(MODULE)] - static THIS_MODULE: kernel::ThisModule = unsafe {{ - kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) - }}; - #[cfg(not(MODULE))] - static THIS_MODULE: kernel::ThisModule = unsafe {{ - kernel::ThisModule::from_ptr(core::ptr::null_mut()) - }}; - - // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. - /// # Safety - /// - /// This function must not be called after module initialization, because it may be - /// freed after that completes. - #[cfg(MODULE)] - #[doc(hidden)] - #[no_mangle] - #[link_section = \".init.text\"] - pub unsafe extern \"C\" fn init_module() -> core::ffi::c_int {{ - __init() - }} + // Double nested modules, since then nobody can access the public items inside. + mod __module_init {{ + mod __module_init {{ + use super::super::{type_}; + + /// The \"Rust loadable module\" mark. + // + // This may be best done another way later on, e.g. as a new modinfo + // key or a new section. For the moment, keep it simple. + #[cfg(MODULE)] + #[doc(hidden)] + #[used] + static __IS_RUST_MODULE: () = (); + + static mut __MOD: Option<{type_}> = None; + + // SAFETY: `__this_module` is constructed by the kernel at load time and will not be + // freed until the module is unloaded. + #[cfg(MODULE)] + static THIS_MODULE: kernel::ThisModule = unsafe {{ + kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) + }}; + #[cfg(not(MODULE))] + static THIS_MODULE: kernel::ThisModule = unsafe {{ + kernel::ThisModule::from_ptr(core::ptr::null_mut()) + }}; + + // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. + /// # Safety + /// + /// This function must not be called after module initialization, because it may be + /// freed after that completes. + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + #[link_section = \".init.text\"] + pub unsafe extern \"C\" fn init_module() -> core::ffi::c_int {{ + __init() + }} - #[cfg(MODULE)] - #[doc(hidden)] - #[no_mangle] - pub extern \"C\" fn cleanup_module() {{ - __exit() - }} + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn cleanup_module() {{ + __exit() + }} - // Built-in modules are initialized through an initcall pointer - // and the identifiers need to be unique. - #[cfg(not(MODULE))] - #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] - #[doc(hidden)] - #[link_section = \"{initcall_section}\"] - #[used] - pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; - - #[cfg(not(MODULE))] - #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] - core::arch::global_asm!( - r#\".section \"{initcall_section}\", \"a\" - __{name}_initcall: - .long __{name}_init - . - .previous - \"# - ); + // Built-in modules are initialized through an initcall pointer + // and the identifiers need to be unique. + #[cfg(not(MODULE))] + #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] + #[doc(hidden)] + #[link_section = \"{initcall_section}\"] + #[used] + pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; + + #[cfg(not(MODULE))] + #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] + core::arch::global_asm!( + r#\".section \"{initcall_section}\", \"a\" + __{name}_initcall: + .long __{name}_init - . + .previous + \"# + ); + + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ + __init() + }} - #[cfg(not(MODULE))] - #[doc(hidden)] - #[no_mangle] - pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ - __init() - }} + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{name}_exit() {{ + __exit() + }} - #[cfg(not(MODULE))] - #[doc(hidden)] - #[no_mangle] - pub extern \"C\" fn __{name}_exit() {{ - __exit() - }} + /// # Safety + /// + /// This function must + /// - only be called once, + /// - not be called concurrently with `__exit`. + unsafe fn __init() -> core::ffi::c_int {{ + match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ + Ok(m) => {{ + // SAFETY: + // no data race, since `__MOD` can only be accessed by this module and + // there only `__init` and `__exit` access it. These functions are only + // called once and `__exit` cannot be called before or during `__init`. + unsafe {{ + __MOD = Some(m); + }} + return 0; + }} + Err(e) => {{ + return e.to_errno(); + }} + }} + }} - fn __init() -> core::ffi::c_int {{ - match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ - Ok(m) => {{ + /// # Safety + /// + /// This function must + /// - only be called once, + /// - be called after `__init`, + /// - not be called concurrently with `__init`. + unsafe fn __exit() {{ + // SAFETY: + // no data race, since `__MOD` can only be accessed by this module and there + // only `__init` and `__exit` access it. These functions are only called once + // and `__init` was already called. unsafe {{ - __MOD = Some(m); + // Invokes `drop()` on `__MOD`, which should be used for cleanup. + __MOD = None; }} - return 0; }} - Err(e) => {{ - return e.to_errno(); - }} - }} - }} - fn __exit() {{ - unsafe {{ - // Invokes `drop()` on `__MOD`, which should be used for cleanup. - __MOD = None; + {modinfo} }} }} - - {modinfo} ", type_ = info.type_, name = info.name, base-commit: 4cece764965020c22cff7665b18a012006359095 -- 2.44.0

1 year, 2 months

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[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

1 year, 2 months

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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

1 year, 2 months

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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

1 year, 2 months

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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

1 year, 2 months

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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>

1 year, 2 months

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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

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