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-rw-r--r--arch/um/include/os.h10
-rw-r--r--arch/um/include/skas/skas.h3
-rw-r--r--arch/um/include/sysdep-i386/archsetjmp.h3
-rw-r--r--arch/um/include/sysdep-x86_64/archsetjmp.h3
-rw-r--r--arch/um/kernel/skas/process_kern.c36
-rw-r--r--arch/um/os-Linux/skas/process.c68
6 files changed, 40 insertions, 83 deletions
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index be71b3d4c961..120ca21a513a 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -14,6 +14,7 @@
#include "skas/mm_id.h"
#include "irq_user.h"
#include "sysdep/tls.h"
+#include "sysdep/archsetjmp.h"
#define OS_TYPE_FILE 1
#define OS_TYPE_DIR 2
@@ -308,12 +309,9 @@ extern int copy_context_skas0(unsigned long stack, int pid);
extern void userspace(union uml_pt_regs *regs);
extern void map_stub_pages(int fd, unsigned long code,
unsigned long data, unsigned long stack);
-extern void new_thread(void *stack, void **switch_buf_ptr,
- void **fork_buf_ptr, void (*handler)(int));
-extern void thread_wait(void *sw, void *fb);
-extern void switch_threads(void *me, void *next);
-extern int start_idle_thread(void *stack, void *switch_buf_ptr,
- void **fork_buf_ptr);
+extern void new_thread(void *stack, jmp_buf *buf, void (*handler)(void));
+extern void switch_threads(jmp_buf *me, jmp_buf *you);
+extern int start_idle_thread(void *stack, jmp_buf *switch_buf);
extern void initial_thread_cb_skas(void (*proc)(void *),
void *arg);
extern void halt_skas(void);
diff --git a/arch/um/include/skas/skas.h b/arch/um/include/skas/skas.h
index 853b26f148c5..e88926b16072 100644
--- a/arch/um/include/skas/skas.h
+++ b/arch/um/include/skas/skas.h
@@ -14,8 +14,7 @@ extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
extern int skas_needs_stub;
extern int user_thread(unsigned long stack, int flags);
-extern void new_thread_proc(void *stack, void (*handler)(int sig));
-extern void new_thread_handler(int sig);
+extern void new_thread_handler(void);
extern void handle_syscall(union uml_pt_regs *regs);
extern int new_mm(unsigned long stack);
extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
diff --git a/arch/um/include/sysdep-i386/archsetjmp.h b/arch/um/include/sysdep-i386/archsetjmp.h
index ea1ba3d42aee..11bafab669e9 100644
--- a/arch/um/include/sysdep-i386/archsetjmp.h
+++ b/arch/um/include/sysdep-i386/archsetjmp.h
@@ -16,4 +16,7 @@ struct __jmp_buf {
typedef struct __jmp_buf jmp_buf[1];
+#define JB_IP __eip
+#define JB_SP __esp
+
#endif /* _SETJMP_H */
diff --git a/arch/um/include/sysdep-x86_64/archsetjmp.h b/arch/um/include/sysdep-x86_64/archsetjmp.h
index 454fc60aff6d..9a5e1a6ec800 100644
--- a/arch/um/include/sysdep-x86_64/archsetjmp.h
+++ b/arch/um/include/sysdep-x86_64/archsetjmp.h
@@ -18,4 +18,7 @@ struct __jmp_buf {
typedef struct __jmp_buf jmp_buf[1];
+#define JB_IP __rip
+#define JB_SP __rsp
+
#endif /* _SETJMP_H */
diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c
index 55caeec8b257..c73d47c57abe 100644
--- a/arch/um/kernel/skas/process_kern.c
+++ b/arch/um/kernel/skas/process_kern.c
@@ -33,7 +33,7 @@ void switch_to_skas(void *prev, void *next)
switch_timers(0);
switch_threads(&from->thread.mode.skas.switch_buf,
- to->thread.mode.skas.switch_buf);
+ &to->thread.mode.skas.switch_buf);
arch_switch_to_skas(current->thread.prev_sched, current);
@@ -43,21 +43,21 @@ void switch_to_skas(void *prev, void *next)
extern void schedule_tail(struct task_struct *prev);
-void new_thread_handler(int sig)
+/* This is called magically, by its address being stuffed in a jmp_buf
+ * and being longjmp-d to.
+ */
+void new_thread_handler(void)
{
int (*fn)(void *), n;
void *arg;
- fn = current->thread.request.u.thread.proc;
- arg = current->thread.request.u.thread.arg;
- os_usr1_signal(1);
- thread_wait(&current->thread.mode.skas.switch_buf,
- current->thread.mode.skas.fork_buf);
-
if(current->thread.prev_sched != NULL)
schedule_tail(current->thread.prev_sched);
current->thread.prev_sched = NULL;
+ fn = current->thread.request.u.thread.proc;
+ arg = current->thread.request.u.thread.arg;
+
/* The return value is 1 if the kernel thread execs a process,
* 0 if it just exits
*/
@@ -70,22 +70,13 @@ void new_thread_handler(int sig)
else do_exit(0);
}
-void new_thread_proc(void *stack, void (*handler)(int sig))
-{
- init_new_thread_stack(stack, handler);
- os_usr1_process(os_getpid());
-}
-
void release_thread_skas(struct task_struct *task)
{
}
-void fork_handler(int sig)
+/* Called magically, see new_thread_handler above */
+void fork_handler(void)
{
- os_usr1_signal(1);
- thread_wait(&current->thread.mode.skas.switch_buf,
- current->thread.mode.skas.fork_buf);
-
force_flush_all();
if(current->thread.prev_sched == NULL)
panic("blech");
@@ -109,7 +100,7 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
unsigned long stack_top, struct task_struct * p,
struct pt_regs *regs)
{
- void (*handler)(int);
+ void (*handler)(void);
if(current->thread.forking){
memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
@@ -128,7 +119,7 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
}
new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
- &p->thread.mode.skas.fork_buf, handler);
+ handler);
return(0);
}
@@ -182,8 +173,7 @@ int start_uml_skas(void)
init_task.thread.request.u.thread.proc = start_kernel_proc;
init_task.thread.request.u.thread.arg = NULL;
return(start_idle_thread(task_stack_page(&init_task),
- &init_task.thread.mode.skas.switch_buf,
- &init_task.thread.mode.skas.fork_buf));
+ &init_task.thread.mode.skas.switch_buf));
}
int external_pid_skas(struct task_struct *task)
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 42e3d1ed802c..cb9ab54146cc 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -444,56 +444,22 @@ void map_stub_pages(int fd, unsigned long code,
}
}
-void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
- void (*handler)(int))
+void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
{
- unsigned long flags;
- jmp_buf switch_buf, fork_buf;
-
- *switch_buf_ptr = &switch_buf;
- *fork_buf_ptr = &fork_buf;
-
- /* Somewhat subtle - siglongjmp restores the signal mask before doing
- * the longjmp. This means that when jumping from one stack to another
- * when the target stack has interrupts enabled, an interrupt may occur
- * on the source stack. This is bad when starting up a process because
- * it's not supposed to get timer ticks until it has been scheduled.
- * So, we disable interrupts around the sigsetjmp to ensure that
- * they can't happen until we get back here where they are safe.
- */
- flags = get_signals();
- block_signals();
- if(UML_SETJMP(&fork_buf) == 0)
- new_thread_proc(stack, handler);
-
- remove_sigstack();
-
- set_signals(flags);
+ (*buf)[0].JB_IP = (unsigned long) handler;
+ (*buf)[0].JB_SP = (unsigned long) stack +
+ (PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) - sizeof(void *);
}
#define INIT_JMP_NEW_THREAD 0
-#define INIT_JMP_REMOVE_SIGSTACK 1
-#define INIT_JMP_CALLBACK 2
-#define INIT_JMP_HALT 3
-#define INIT_JMP_REBOOT 4
-
-void thread_wait(void *sw, void *fb)
-{
- jmp_buf buf, **switch_buf = sw, *fork_buf;
-
- *switch_buf = &buf;
- fork_buf = fb;
- if(UML_SETJMP(&buf) == 0)
- UML_LONGJMP(fork_buf, INIT_JMP_REMOVE_SIGSTACK);
-}
+#define INIT_JMP_CALLBACK 1
+#define INIT_JMP_HALT 2
+#define INIT_JMP_REBOOT 3
-void switch_threads(void *me, void *next)
+void switch_threads(jmp_buf *me, jmp_buf *you)
{
- jmp_buf my_buf, **me_ptr = me, *next_buf = next;
-
- *me_ptr = &my_buf;
- if(UML_SETJMP(&my_buf) == 0)
- UML_LONGJMP(next_buf, 1);
+ if(UML_SETJMP(me) == 0)
+ UML_LONGJMP(you, 1);
}
static jmp_buf initial_jmpbuf;
@@ -503,23 +469,21 @@ static void (*cb_proc)(void *arg);
static void *cb_arg;
static jmp_buf *cb_back;
-int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
+int start_idle_thread(void *stack, jmp_buf *switch_buf)
{
- jmp_buf **switch_buf = switch_buf_ptr;
int n;
set_handler(SIGWINCH, (__sighandler_t) sig_handler,
SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGALRM,
SIGVTALRM, -1);
- *fork_buf_ptr = &initial_jmpbuf;
n = UML_SETJMP(&initial_jmpbuf);
switch(n){
case INIT_JMP_NEW_THREAD:
- new_thread_proc((void *) stack, new_thread_handler);
- break;
- case INIT_JMP_REMOVE_SIGSTACK:
- remove_sigstack();
+ (*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler;
+ (*switch_buf)[0].JB_SP = (unsigned long) stack +
+ (PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) -
+ sizeof(void *);
break;
case INIT_JMP_CALLBACK:
(*cb_proc)(cb_arg);
@@ -534,7 +498,7 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
default:
panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
}
- UML_LONGJMP(*switch_buf, 1);
+ UML_LONGJMP(switch_buf, 1);
}
void initial_thread_cb_skas(void (*proc)(void *), void *arg)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 14:56:42 +0100