Commit 96e59245 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

[PATCH] uml: remove debugging code from page fault path 



This eliminates the segfault info ring buffer, which added a system call to
each page fault, and which hadn't been useful for debugging in ages.

Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 49f9ebc8

arch/um/kernel/trap_kern.c

+0 −27
Original line number Diff line number Diff line
@@ -200,30 +200,3 @@ void winch(int sig, union uml_pt_regs *regs) 
void trap_init(void)

{

}
 


DEFINE_SPINLOCK(trap_lock);



static int trap_index = 0;



int next_trap_index(int limit)

{

	int ret;



	spin_lock(&trap_lock);

	ret = trap_index;

	if(++trap_index == limit)

		trap_index = 0;

	spin_unlock(&trap_lock);

	return(ret);

}



/*

 * Overrides for Emacs so that we follow Linus's tabbing style.

 * Emacs will notice this stuff at the end of the file and automatically

 * adjust the settings for this buffer only.  This must remain at the end

 * of the file.

 * ---------------------------------------------------------------------------

 * Local variables:

 * c-file-style: "linux"

 * End:

 */

arch/um/kernel/trap_user.c

+0 −21
Original line number Diff line number Diff line
@@ -40,35 +40,14 @@ void kill_child_dead(int pid) 
	} while(1);

}



/* Unlocked - don't care if this is a bit off */

int nsegfaults = 0;



struct {

	unsigned long address;

	int is_write;

	int pid;

	unsigned long sp;

	int is_user;

} segfault_record[1024];



void segv_handler(int sig, union uml_pt_regs *regs)

{

	int index, max;

        struct faultinfo * fi = UPT_FAULTINFO(regs);



        if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){

                bad_segv(*fi, UPT_IP(regs));

		return;

	}

	max = sizeof(segfault_record)/sizeof(segfault_record[0]);

	index = next_trap_index(max);



	nsegfaults++;

        segfault_record[index].address = FAULT_ADDRESS(*fi);

	segfault_record[index].pid = os_getpid();

        segfault_record[index].is_write = FAULT_WRITE(*fi);

	segfault_record[index].sp = UPT_SP(regs);

	segfault_record[index].is_user = UPT_IS_USER(regs);

        segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);

}