[PATCH 4/8] fork: move PF_IO_WORKER's kernel frame setup to new flag
From: Mike Christie <michael.christie@oracle.com>
Date: 2021-09-16 21:21:29
Also in:
lkml
Subsystem:
exec & binfmt api, elf, memory management - core, scheduler, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Kees Cook, Andrew Morton, David Hildenbrand, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen
The vhost worker threads need the same frame setup as io_uring's worker threads, but do not handle signals and may not even be executing IO. This moves the setup part to a new flag. Signed-off-by: Mike Christie <michael.christie@oracle.com> --- arch/x86/kernel/process.c | 4 ++-- include/linux/sched.h | 1 + include/linux/sched/task.h | 1 + kernel/fork.c | 3 +++ 4 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 1d9463e3096b..ccdec11cd120 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c@@ -178,9 +178,9 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, task_user_gs(p) = get_user_gs(current_pt_regs()); #endif - if (unlikely(p->flags & PF_IO_WORKER)) { + if (unlikely(p->flags & PF_USER_WORKER)) { /* - * An IO thread is a user space thread, but it doesn't + * An user worker thread is a user space thread, but it doesn't * return to ret_after_fork(). * * In order to indicate that to tools like gdb,
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e12b524426b0..817d3a7bec77 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h@@ -1664,6 +1664,7 @@ extern struct pid *cad_pid; #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ #define PF_IDLE 0x00000002 /* I am an IDLE thread */ #define PF_EXITING 0x00000004 /* Getting shut down */ +#define PF_USER_WORKER 0x00000008 /* Userspace kernel worker */ #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index d0b0872f56cc..4a6100a24894 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h@@ -33,6 +33,7 @@ struct kernel_clone_args { int cgroup; int io_thread; int no_files; + int user_worker; struct cgroup *cgrp; struct css_set *cset; };
diff --git a/kernel/fork.c b/kernel/fork.c
index a0468e30b27e..1dda1d4ea77b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c@@ -2041,6 +2041,8 @@ static __latent_entropy struct task_struct *copy_process( siginitsetinv(&p->blocked, sigmask(SIGKILL)|sigmask(SIGSTOP)); } + if (args->user_worker) + p->flags |= PF_USER_WORKER; /* * This _must_ happen before we call free_task(), i.e. before we jump * to any of the bad_fork_* labels. This is to avoid freeing
@@ -2563,6 +2565,7 @@ struct task_struct *kernel_copy_process(int (*fn)(void *), void *arg, int node, .stack_size = (unsigned long)arg, .io_thread = io_thread, .no_files = no_files, + .user_worker = 1, }; return copy_process(NULL, 0, node, &args);
--
2.25.1
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