This commit introduces additional argument of previous task when context switch happens. New SUBARCH can use the new information to switch tasks in a subarch-specific manner. The patch is particularly required by nommu mode implemented as a SUBARCH of UML. Signed-off-by: Hajime Tazaki <thehajime@xxxxxxxxx> --- arch/um/kernel/process.c | 6 +++--- arch/x86/um/ptrace_32.c | 2 +- arch/x86/um/syscalls_64.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 26b5e243d3fc..87a8cfa228ca 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -80,7 +80,7 @@ static inline void set_current(struct task_struct *task) { external_pid(), task }); } -extern void arch_switch_to(struct task_struct *to); +extern void arch_switch_to(struct task_struct *from, struct task_struct *to); void *__switch_to(struct task_struct *from, struct task_struct *to) { @@ -88,7 +88,7 @@ void *__switch_to(struct task_struct *from, struct task_struct *to) set_current(to); switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); - arch_switch_to(current); + arch_switch_to(from, to); return current->thread.prev_sched; } @@ -145,7 +145,7 @@ void fork_handler(void) * arch_switch_to isn't needed. We could want to apply this to * improve performance. -bb */ - arch_switch_to(current); + arch_switch_to(NULL, current); current->thread.prev_sched = NULL; diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c index 2497bac56066..0f184710d4ca 100644 --- a/arch/x86/um/ptrace_32.c +++ b/arch/x86/um/ptrace_32.c @@ -11,7 +11,7 @@ extern int arch_switch_tls(struct task_struct *to); -void arch_switch_to(struct task_struct *to) +void arch_switch_to(struct task_struct *from, struct task_struct *to) { int err = arch_switch_tls(to); if (!err) diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c index 58f51667e2e4..2ef9474d2bd2 100644 --- a/arch/x86/um/syscalls_64.c +++ b/arch/x86/um/syscalls_64.c @@ -80,7 +80,7 @@ SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2) return arch_prctl(current, option, (unsigned long __user *) arg2); } -void arch_switch_to(struct task_struct *to) +void arch_switch_to(struct task_struct *from, struct task_struct *to) { if ((to->thread.arch.fs == 0) || (to->mm == NULL)) return; -- 2.21.0 (Apple Git-122.2)