diff options
Diffstat (limited to 'SOURCES/fsync.patch')
| -rw-r--r-- | SOURCES/fsync.patch | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/SOURCES/fsync.patch b/SOURCES/fsync.patch new file mode 100644 index 0000000..7fa3fef --- /dev/null +++ b/SOURCES/fsync.patch @@ -0,0 +1,165 @@ +From b70e738f08403950aa3053c36b98c6b0eeb0eb90 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Andr=C3=A9=20Almeida?= <andrealmeid@collabora.com> +Date: Mon, 25 Oct 2021 09:49:42 -0300 +Subject: [PATCH] futex: Add entry point for FUTEX_WAIT_MULTIPLE (opcode 31) +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Add an option to wait on multiple futexes using the old interface, that +uses opcode 31 through futex() syscall. Do that by just translation the +old interface to use the new code. This allows old and stable versions +of Proton to still use fsync in new kernel releases. + +Signed-off-by: André Almeida <andrealmeid@collabora.com> +--- + include/uapi/linux/futex.h | 12 ++++++ + kernel/futex.c | 75 +++++++++++++++++++++++++++++++++++++- + 2 files changed, 86 insertions(+), 1 deletion(-) + +diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h +index 2a06b99f9803..417c5d89b745 100644 +--- a/include/uapi/linux/futex.h ++++ b/include/uapi/linux/futex.h +@@ -22,6 +22,7 @@ + #define FUTEX_WAIT_REQUEUE_PI 11 + #define FUTEX_CMP_REQUEUE_PI 12 + #define FUTEX_LOCK_PI2 13 ++#define FUTEX_WAIT_MULTIPLE 31 + + #define FUTEX_PRIVATE_FLAG 128 + #define FUTEX_CLOCK_REALTIME 256 +@@ -68,6 +69,17 @@ struct futex_waitv { + __u32 __reserved; + }; + ++/** ++ * struct futex_wait_block - Block of futexes to be waited for ++ * @uaddr: User address of the futex ++ * @val: Futex value expected by userspace ++ * @bitset: Bitset for the optional bitmasked wakeup ++ */ ++struct futex_wait_block { ++ __u32 __user *uaddr; ++ __u32 val; ++ __u32 bitset; ++}; + + /* + * Support for robust futexes: the kernel cleans up held futexes at +diff --git a/kernel/futex.c b/kernel/futex.c +index 4a9e7ce3714a..c3f2e65afab8 100644 +--- a/kernel/futex.c ++++ b/kernel/futex.c +@@ -4012,6 +4012,7 @@ static __always_inline bool futex_cmd_has_timeout(u32 cmd) + case FUTEX_LOCK_PI2: + case FUTEX_WAIT_BITSET: + case FUTEX_WAIT_REQUEUE_PI: ++ case FUTEX_WAIT_MULTIPLE: + return true; + } + return false; +@@ -4024,13 +4025,79 @@ futex_init_timeout(u32 cmd, u32 op, struct timespec64 *ts, ktime_t *t) + return -EINVAL; + + *t = timespec64_to_ktime(*ts); +- if (cmd == FUTEX_WAIT) ++ if (cmd == FUTEX_WAIT || cmd == FUTEX_WAIT_MULTIPLE) + *t = ktime_add_safe(ktime_get(), *t); + else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME)) + *t = timens_ktime_to_host(CLOCK_MONOTONIC, *t); + return 0; + } + ++/** ++ * futex_read_wait_block - Read an array of futex_wait_block from userspace ++ * @uaddr: Userspace address of the block ++ * @count: Number of blocks to be read ++ * ++ * This function creates and allocate an array of futex_q (we zero it to ++ * initialize the fields) and then, for each futex_wait_block element from ++ * userspace, fill a futex_q element with proper values. ++ */ ++inline struct futex_vector *futex_read_wait_block(u32 __user *uaddr, u32 count) ++{ ++ unsigned int i; ++ struct futex_vector *futexv; ++ struct futex_wait_block fwb; ++ struct futex_wait_block __user *entry = ++ (struct futex_wait_block __user *)uaddr; ++ ++ if (!count || count > FUTEX_WAITV_MAX) ++ return ERR_PTR(-EINVAL); ++ ++ futexv = kcalloc(count, sizeof(*futexv), GFP_KERNEL); ++ if (!futexv) ++ return ERR_PTR(-ENOMEM); ++ ++ for (i = 0; i < count; i++) { ++ if (copy_from_user(&fwb, &entry[i], sizeof(fwb))) { ++ kfree(futexv); ++ return ERR_PTR(-EFAULT); ++ } ++ ++ futexv[i].w.flags = FUTEX_32; ++ futexv[i].w.val = fwb.val; ++ futexv[i].w.uaddr = (uintptr_t) (fwb.uaddr); ++ futexv[i].q = futex_q_init; ++ } ++ ++ return futexv; ++} ++ ++int futex_wait_multiple(struct futex_vector *vs, unsigned int count, ++ struct hrtimer_sleeper *to); ++ ++int futex_opcode_31(ktime_t *abs_time, u32 __user *uaddr, int count) ++{ ++ int ret; ++ struct futex_vector *vs; ++ struct hrtimer_sleeper *to = NULL, timeout; ++ ++ to = futex_setup_timer(abs_time, &timeout, 0, 0); ++ ++ vs = futex_read_wait_block(uaddr, count); ++ ++ if (IS_ERR(vs)) ++ return PTR_ERR(vs); ++ ++ ret = futex_wait_multiple(vs, count, abs_time ? to : NULL); ++ kfree(vs); ++ ++ if (to) { ++ hrtimer_cancel(&to->timer); ++ destroy_hrtimer_on_stack(&to->timer); ++ } ++ ++ return ret; ++} ++ + SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, + const struct __kernel_timespec __user *, utime, + u32 __user *, uaddr2, u32, val3) +@@ -4050,6 +4117,9 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, + tp = &t; + } + ++ if (cmd == FUTEX_WAIT_MULTIPLE) ++ return futex_opcode_31(tp, uaddr, val); ++ + return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); + } + +@@ -4551,6 +4621,9 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val, + tp = &t; + } + ++ if (cmd == FUTEX_WAIT_MULTIPLE) ++ return futex_opcode_31(tp, uaddr, val); ++ + return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); + } + #endif /* CONFIG_COMPAT_32BIT_TIME */ +-- +2.33.1 + |