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authorEric W. Biederman <ebiederm@xmission.com>2022-04-12 17:18:48 +0200
committerEric W. Biederman <ebiederm@xmission.com>2022-05-07 16:01:59 +0200
commit5bd2e97c868a8a44470950ed01846cab6328e540 (patch)
tree7919866d9e44b6c98bfe16f6ac436013ce9e75c0 /arch/xtensa
parentfork: Explicity test for idle tasks in copy_thread (diff)
downloadlinux-5bd2e97c868a8a44470950ed01846cab6328e540.tar.xz
linux-5bd2e97c868a8a44470950ed01846cab6328e540.zip
fork: Generalize PF_IO_WORKER handling
Add fn and fn_arg members into struct kernel_clone_args and test for them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER). This allows any task that wants to be a user space task that only runs in kernel mode to use this functionality. The code on x86 is an exception and still retains a PF_KTHREAD test because x86 unlikely everything else handles kthreads slightly differently than user space tasks that start with a function. The functions that created tasks that start with a function have been updated to set ".fn" and ".fn_arg" instead of ".stack" and ".stack_size". These functions are fork_idle(), create_io_thread(), kernel_thread(), and user_mode_thread(). Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/kernel/process.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 15ce25073142..c3751cc88e5d 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -205,7 +205,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
unsigned long clone_flags = args->flags;
unsigned long usp_thread_fn = args->stack;
- unsigned long thread_fn_arg = args->stack_size;
unsigned long tls = args->tls;
struct pt_regs *childregs = task_pt_regs(p);
@@ -226,7 +225,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
#error Unsupported Xtensa ABI
#endif
- if (!(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
+ if (!args->fn) {
struct pt_regs *regs = current_pt_regs();
unsigned long usp = usp_thread_fn ?
usp_thread_fn : regs->areg[1];
@@ -278,15 +277,15 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
* Window underflow will load registers from the
* spill slots on the stack on return from _switch_to.
*/
- SPILL_SLOT(childregs, 2) = usp_thread_fn;
- SPILL_SLOT(childregs, 3) = thread_fn_arg;
+ SPILL_SLOT(childregs, 2) = (unsigned long)args->fn;
+ SPILL_SLOT(childregs, 3) = (unsigned long)args->fn_arg;
#elif defined(__XTENSA_CALL0_ABI__)
/*
* a12 = thread_fn, a13 = thread_fn arg.
* _switch_to epilogue will load registers from the stack.
*/
- ((unsigned long *)p->thread.sp)[0] = usp_thread_fn;
- ((unsigned long *)p->thread.sp)[1] = thread_fn_arg;
+ ((unsigned long *)p->thread.sp)[0] = (unsigned long)args->fn;
+ ((unsigned long *)p->thread.sp)[1] = (unsigned long)args->fn_arg;
#else
#error Unsupported Xtensa ABI
#endif