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Commit f5741644 authored by Keith Owens's avatar Keith Owens Committed by Andi Kleen
Browse files

[PATCH] Remove most of the special cases for the debug IST stack 



Remove most of the special cases for the debug IST stack.  This is a
follow on clean up patch, it requires the bug fix patch that adds
orig_ist.

Signed-off-by: default avatarKeith Owens <kaos@ocs.com.au>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 575400d1

arch/x86_64/kernel/setup64.c

+5 −16
Original line number Diff line number Diff line
@@ -237,28 +237,17 @@ void __cpuinit cpu_init (void) 
	 * set up and load the per-CPU TSS

	 */

	for (v = 0; v < N_EXCEPTION_STACKS; v++) {

		if (cpu) {

		static const unsigned int order[N_EXCEPTION_STACKS] = {

			[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,

			[DEBUG_STACK - 1] = DEBUG_STACK_ORDER

		};



		if (cpu) {

			estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);

			if (!estacks)

				panic("Cannot allocate exception stack %ld %d\n",

				      v, cpu); 

		}

		switch (v + 1) {

#if DEBUG_STKSZ > EXCEPTION_STKSZ

		case DEBUG_STACK:

			cpu_pda(cpu)->debugstack = (unsigned long)estacks;

			estacks += DEBUG_STKSZ;

			break;

#endif

		default:

			estacks += EXCEPTION_STKSZ;

			break;

		}

		estacks += PAGE_SIZE << order[v];

		orig_ist->ist[v] = t->ist[v] = (unsigned long)estacks;

	}

arch/x86_64/kernel/traps.c

+1 −20
Original line number Diff line number Diff line
@@ -162,26 +162,7 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, 
	 * 'stack' is in one of them:

	 */

	for (k = 0; k < N_EXCEPTION_STACKS; k++) {

		unsigned long end;



		/*

		 * set 'end' to the end of the exception stack.

		 */

		switch (k + 1) {

		/*

		 * TODO: this block is not needed i think, because

		 * setup64.c:cpu_init() sets up t->ist[DEBUG_STACK]

		 * properly too.

		 */

#if DEBUG_STKSZ > EXCEPTION_STKSZ

		case DEBUG_STACK:

			end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;

			break;

#endif

		default:

			end = per_cpu(orig_ist, cpu).ist[k];

			break;

		}

		unsigned long end = per_cpu(orig_ist, cpu).ist[k];

		/*

		 * Is 'stack' above this exception frame's end?

		 * If yes then skip to the next frame.

include/asm-x86_64/pda.h

+0 −3
Original line number Diff line number Diff line
@@ -13,9 +13,6 @@ struct x8664_pda { 
	unsigned long data_offset;	/* Per cpu data offset from linker address */

	unsigned long kernelstack;  /* top of kernel stack for current */ 

	unsigned long oldrsp; 	    /* user rsp for system call */

#if DEBUG_STKSZ > EXCEPTION_STKSZ

	unsigned long debugstack;   /* #DB/#BP stack. */

#endif

        int irqcount;		    /* Irq nesting counter. Starts with -1 */  	

	int cpunumber;		    /* Logical CPU number */

	char *irqstackptr;	/* top of irqstack */