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Commit e634d8fc authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86-64: merge the standard and compat start_thread() functions 



The only thing left that differs between the standard and compat
start_thread functions is the actual segment numbers and the
prototype, so have a single common function which contains the guts
and two very small wrappers.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Acked-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
parent a6f05a6a

arch/x86/kernel/process_64.c

+17 −22
Original line number Diff line number Diff line
@@ -344,18 +344,20 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, 
	return err;

}



void

start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)

static void

start_thread_common(struct pt_regs *regs, unsigned long new_ip,

		    unsigned long new_sp,

		    unsigned int _cs, unsigned int _ss, unsigned int _ds)

{

	loadsegment(fs, 0);

	loadsegment(es, 0);

	loadsegment(ds, 0);

	loadsegment(es, _ds);

	loadsegment(ds, _ds);

	load_gs_index(0);

	regs->ip		= new_ip;

	regs->sp		= new_sp;

	percpu_write(old_rsp, new_sp);

	regs->cs		= __USER_CS;

	regs->ss		= __USER_DS;

	regs->cs		= _cs;

	regs->ss		= _ss;

	regs->flags		= X86_EFLAGS_IF;

	set_fs(USER_DS);

	/*
@@ -363,26 +365,19 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) 
	 */

	free_thread_xstate(current);

}

EXPORT_SYMBOL_GPL(start_thread);



void

start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)

{

	start_thread_common(regs, new_ip, new_sp,

			    __USER_CS, __USER_DS, 0);

}



#ifdef CONFIG_IA32_EMULATION

void start_thread_ia32(struct pt_regs *regs, u32 new_ip, u32 new_sp)

{

	loadsegment(fs, 0);

	loadsegment(ds, __USER32_DS);

	loadsegment(es, __USER32_DS);

	load_gs_index(0);

	regs->ip		= new_ip;

	regs->sp		= new_sp;

	percpu_write(old_rsp, new_sp);

	regs->cs		= __USER32_CS;

	regs->ss		= __USER32_DS;

	regs->flags		= X86_EFLAGS_IF;

	set_fs(USER_DS);

	/*

	 * Free the old FP and other extended state

	 */

	free_thread_xstate(current);

	start_thread_common(regs, new_ip, new_sp,

			    __USER32_CS, __USER32_DS, __USER32_DS);

}

#endif