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author | Jean-Marc Lenoir | 2021-08-01 10:25:51 +0200 |
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committer | Jean-Marc Lenoir | 2021-08-01 10:25:51 +0200 |
commit | 6434678fc59a9f41eeec76fe2e0b16b84c3c0c26 (patch) | |
tree | 3867a597f4c3da16e9a6807899c5e0375046acf5 /vmmon.patch | |
parent | 40bd04cf9a5d029d78cb2d2d21b635641224bb94 (diff) | |
download | aur-6434678fc59a9f41eeec76fe2e0b16b84c3c0c26.tar.gz |
Compatibility with Linux 5.14-rc1
Diffstat (limited to 'vmmon.patch')
-rw-r--r-- | vmmon.patch | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/vmmon.patch b/vmmon.patch index b8793376c863..19ba25431813 100644 --- a/vmmon.patch +++ b/vmmon.patch @@ -233,3 +233,99 @@ /* * Do not exit thread until we are told to do so. */ +From 9fda02bce13527ce94a95df1a98fb6188dea22b8 Mon Sep 17 00:00:00 2001 +From: Michal Kubecek <mkubecek@suse.cz> +Date: Wed, 30 Jun 2021 11:05:16 +0200 +Subject: [PATCH] vmmon: fix task_struct::state access patterns + +Mainline commit 2f064a59a11f ("sched: Change task_struct::state") in +5.14-rc1 finishes a series fixing racy access patterns to task state and +renames task_struct::state to __state so that code old code acessing it +directly fails to build. + +Two of these in HostIF_SemaphoreWait() can be rewritten into calls to +set_current_state() unconditionally (second one may do with +__set_current_state() but I don't feel confident enough about that). +There are also two places where vmmon code reads task_struct::state; +provide a compat accessor using READ_ONCE() and use it instead of +a direct read. To avoid kernel version check, check presence of +get_current_state() macro introduced in the same commit as state member +rename. +--- + vmmon-only/include/compat_sched.h | 15 +++++++++++++++ + vmmon-only/linux/hostif.c | 10 ++++++---- + 2 files changed, 21 insertions(+), 4 deletions(-) + +diff --git a/vmmon-only/include/compat_sched.h b/vmmon-only/include/compat_sched.h +index 3f3304b..72078e0 100644 +--- a/vmmon-only/include/compat_sched.h ++++ b/vmmon-only/include/compat_sched.h +@@ -289,5 +289,20 @@ typedef struct pid * compat_pid; + #define compat_kill_pid(pid, sig, flag) kill_pid(pid, sig, flag) + #endif + ++/* ++ * Since v5.14-rc1, task_struct::state hase been renamed to __state and is ++ * is longer supposed to be accessed without READ_ONCE/WRITE_ONCE. ++ */ ++#ifdef get_current_state ++static inline int compat_get_task_state(const struct task_struct *t) ++{ ++ return READ_ONCE(t->__state); ++} ++#else ++static inline int compat_get_task_state(const struct task_struct *t) ++{ ++ return READ_ONCE(t->state); ++} ++#endif + + #endif /* __COMPAT_SCHED_H__ */ +diff --git a/vmmon-only/linux/hostif.c b/vmmon-only/linux/hostif.c +index 137062c..6910f69 100644 +--- a/vmmon-only/linux/hostif.c ++++ b/vmmon-only/linux/hostif.c +@@ -79,6 +79,8 @@ + #include "pgtbl.h" + #include "versioned_atomic.h" + ++#include "compat_sched.h" ++ + #if !defined(CONFIG_HIGH_RES_TIMERS) + #error CONFIG_HIGH_RES_TIMERS required for acceptable performance + #endif +@@ -466,7 +468,7 @@ HostIF_WakeUpYielders(VMDriver *vm, // IN: + ASSERT(vcpuid < vm->numVCPUs); + t = vm->vmhost->vcpuSemaTask[vcpuid]; + VCPUSet_Remove(&req, vcpuid); +- if (t && (t->state & TASK_INTERRUPTIBLE)) { ++ if (t && (compat_get_task_state(t) & TASK_INTERRUPTIBLE)) { + wake_up_process(t); + } + } +@@ -2613,14 +2615,14 @@ HostIF_SemaphoreWait(VMDriver *vm, // IN: + unsigned int mask; + + poll_initwait(&table); +- current->state = TASK_INTERRUPTIBLE; ++ set_current_state(TASK_INTERRUPTIBLE); + mask = file->f_op->poll(file, &table.pt); + if (!(mask & (POLLIN | POLLERR | POLLHUP))) { + vm->vmhost->vcpuSemaTask[vcpuid] = current; + schedule_timeout(timeoutms * HZ / 1000); // convert to Hz + vm->vmhost->vcpuSemaTask[vcpuid] = NULL; + } +- current->state = TASK_RUNNING; ++ set_current_state(TASK_RUNNING); + poll_freewait(&table); + } + +@@ -2698,7 +2700,7 @@ HostIF_SemaphoreForceWakeup(VMDriver *vm, // IN: + */ + struct task_struct *t = + (struct task_struct *)xchg(&vm->vmhost->vcpuSemaTask[vcpuid], NULL); +- if (t && (t->state & TASK_INTERRUPTIBLE)) { ++ if (t && (compat_get_task_state(t) & TASK_INTERRUPTIBLE)) { + wake_up_process(t); + } + } ROF_EACH_VCPU_IN_SET_WITH_MAX(); |