x86: Introduce restart_block->arch_data to remove TS_COMPAT_RESTART

Save the current_thread_info()->status of X86 in the new
restart_block->arch_data field so TS_COMPAT_RESTART can be removed again.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210201174716.GA17898@redhat.com

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 30d1d18..06b740b 100644 (file)
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -217,18 +217,10 @@ static inline int arch_within_stack_frames(const void * const stack,
 #ifndef __ASSEMBLY__
 #ifdef CONFIG_COMPAT
 #define TS_I386_REGS_POKED     0x0004  /* regs poked by 32-bit ptracer */
-#define TS_COMPAT_RESTART      0x0008
 
-#define arch_set_restart_data  arch_set_restart_data
+#define arch_set_restart_data(restart) \
+       do { restart->arch_data = current_thread_info()->status; } while (0)
 
-static inline void arch_set_restart_data(struct restart_block *restart)
-{
-       struct thread_info *ti = current_thread_info();
-       if (ti->status & TS_COMPAT)
-               ti->status |= TS_COMPAT_RESTART;
-       else
-               ti->status &= ~TS_COMPAT_RESTART;
-}
 #endif
 
 #ifdef CONFIG_X86_32

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 6c26d2c..f306e85 100644 (file)
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -767,7 +767,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
 {
 #ifdef CONFIG_IA32_EMULATION
-       if (current_thread_info()->status & TS_COMPAT_RESTART)
+       if (current->restart_block.arch_data & TS_COMPAT)
                return __NR_ia32_restart_syscall;
 #endif
 #ifdef CONFIG_X86_X32_ABI

diff --git a/include/linux/restart_block.h b/include/linux/restart_block.h
index bba2920..980a655 100644 (file)
--- a/include/linux/restart_block.h
+++ b/include/linux/restart_block.h
@@ -23,6 +23,7 @@ enum timespec_type {
  * System call restart block.
  */
 struct restart_block {
+       unsigned long arch_data;
        long (*fn)(struct restart_block *);
        union {
                /* For futex_wait and futex_wait_requeue_pi */