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Commit ce90f340 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
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x86: x86-64 ptrace get/putreg current task 



This generalizes the getreg and putreg functions so they can be used on the
current task, as well as on a task stopped in TASK_TRACED and switched off.
This lays the groundwork to share this code for all kinds of user-mode
machine state access, not just ptrace.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9e714bed

arch/x86/kernel/ptrace_64.c

+34 −2
Original line number Diff line number Diff line
@@ -67,21 +67,29 @@ static int putreg(struct task_struct *child, 
		if (value && (value & 3) != 3)

			return -EIO;

		child->thread.fsindex = value & 0xffff;

		if (child == current)

			loadsegment(fs, child->thread.fsindex);

		return 0;

	case offsetof(struct user_regs_struct,gs):

		if (value && (value & 3) != 3)

			return -EIO;

		child->thread.gsindex = value & 0xffff;

		if (child == current)

			load_gs_index(child->thread.gsindex);

		return 0;

	case offsetof(struct user_regs_struct,ds):

		if (value && (value & 3) != 3)

			return -EIO;

		child->thread.ds = value & 0xffff;

		if (child == current)

			loadsegment(ds, child->thread.ds);

		return 0;

	case offsetof(struct user_regs_struct,es):

		if (value && (value & 3) != 3)

			return -EIO;

		child->thread.es = value & 0xffff;

		if (child == current)

			loadsegment(es, child->thread.es);

		return 0;

	case offsetof(struct user_regs_struct,ss):

		if ((value & 3) != 3)
@@ -135,14 +143,32 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) 
{

	struct pt_regs *regs = task_pt_regs(child);

	unsigned long val;

	unsigned int seg;

	switch (regno) {

	case offsetof(struct user_regs_struct, fs):

		if (child == current) {

			/* Older gas can't assemble movq %?s,%r?? */

			asm("movl %%fs,%0" : "=r" (seg));

			return seg;

		}

		return child->thread.fsindex;

	case offsetof(struct user_regs_struct, gs):

		if (child == current) {

			asm("movl %%gs,%0" : "=r" (seg));

			return seg;

		}

		return child->thread.gsindex;

	case offsetof(struct user_regs_struct, ds):

		if (child == current) {

			asm("movl %%ds,%0" : "=r" (seg));

			return seg;

		}

		return child->thread.ds;

	case offsetof(struct user_regs_struct, es):

		if (child == current) {

			asm("movl %%es,%0" : "=r" (seg));

			return seg;

		}

		return child->thread.es;

	case offsetof(struct user_regs_struct, fs_base):

		/*
@@ -152,7 +178,10 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) 
		 */

		if (child->thread.fs != 0)

			return child->thread.fs;

		if (child->thread.fsindex != FS_TLS_SEL)

		seg = child->thread.fsindex;

		if (child == current)

			asm("movl %%fs,%0" : "=r" (seg));

		if (seg != FS_TLS_SEL)

			return 0;

		return get_desc_base(&child->thread.tls_array[FS_TLS]);

	case offsetof(struct user_regs_struct, gs_base):
@@ -161,7 +190,10 @@ static unsigned long getreg(struct task_struct *child, unsigned long regno) 
		 */

		if (child->thread.gs != 0)

			return child->thread.gs;

		if (child->thread.gsindex != GS_TLS_SEL)

		seg = child->thread.gsindex;

		if (child == current)

			asm("movl %%gs,%0" : "=r" (seg));

		if (seg != GS_TLS_SEL)

			return 0;

		return get_desc_base(&child->thread.tls_array[GS_TLS]);

	case offsetof(struct user_regs_struct, flags):