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Introduce TIF_IRET and use it to disable sysexit

PATCH In review Luca Barbieri 2 participants 2 messages Jan 6, 2003

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#0 lore raw

PATCH 1/1 Introduce TIF_IRET and use it to disable sysexit

This patch introduces a new flag called TIF_IRET and uses it in place of TIF_SIGPENDING when that flag is used to force return via iret.

This avoids the overhead of calling do_signal and makes the code easier to understand.

arch/i386/kernel/ioport.c +1 -1
diff --exclude-from=/home/ldb/src/exclude -urNdp --exclude='speedtouch.*' --exclude='atmsar.*' linux-2.5.54/arch/i386/kernel/ioport.c linux-2.5.54-ldb/arch/i386/kernel/ioport.c
@@ -124,6 +124,6 @@ asmlinkage int sys_iopl(unsigned long un
 	}
 	regs->eflags = (regs->eflags & 0xffffcfff) | (level << 12);
 	/* Make sure we return the long way (not sysenter) */
-	set_thread_flag(TIF_SIGPENDING);
+	set_thread_flag(TIF_IRET);
 	return 0;
 }
arch/i386/kernel/process.c +1 -1
diff --exclude-from=/home/ldb/src/exclude -urNdp --exclude='speedtouch.*' --exclude='atmsar.*' linux-2.5.54/arch/i386/kernel/process.c linux-2.5.54-ldb/arch/i386/kernel/process.c
@@ -561,7 +561,7 @@ asmlinkage int sys_execve(struct pt_regs
 	if (error == 0) {
 		current->ptrace &= ~PT_DTRACE;
 		/* Make sure we don't return using sysenter.. */
-		set_thread_flag(TIF_SIGPENDING);
+		set_thread_flag(TIF_IRET);
 	}
 	putname(filename);
 out:
arch/i386/kernel/signal.c +2 -0
diff --exclude-from=/home/ldb/src/exclude -urNdp --exclude='speedtouch.*' --exclude='atmsar.*' linux-2.5.54/arch/i386/kernel/signal.c linux-2.5.54-ldb/arch/i386/kernel/signal.c
@@ -617,4 +619,6 @@ void do_notify_resume(struct pt_regs *re
 	/* deal with pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs,oldset);
+	
+	clear_thread_flag(TIF_IRET);
 }
include/asm-i386/thread_info.h +2 -0
diff --exclude-from=/home/ldb/src/exclude -urNdp --exclude='speedtouch.*' --exclude='atmsar.*' linux-2.5.54/include/asm-i386/thread_info.h linux-2.5.54-ldb/include/asm-i386/thread_info.h
@@ -110,6 +110,7 @@ static inline struct thread_info *curren
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
+#define TIF_IRET		5	/* return with iret */
 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
 #define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 
@@ -118,6 +119,7 @@ static inline struct thread_info *curren
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
+#define _TIF_IRET		(1<<TIF_IRET)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
#1 lore raw
Quoted 3 lines · Luca Barbieri

This patch introduces a new flag called TIF_IRET and uses it in place of TIF_SIGPENDING when that flag is used to force return via iret.

Thanks. Both (this and the %ebp fix) patches applied, looks fine.

Linus