Commit 42daba31 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: stop saving process FP state 



Throw out a lot of code dealing with saving and restoring floating-point
state.  In skas mode, where processes run in a restoring floating-point state
on kernel entry and exit is pointless.

This eliminates most of arch/um/os-Linux/sys-{i386,x86_64}/registers.c.  Most
of what remained is now arch-indpendent, and can be moved up to
arch/um/os-Linux/registers.c.  Both arches need the jmp_buf accessor
get_thread_reg, and i386 needs {save,restore}_fp_regs because it cheats during
sigreturn by getting the fp state using ptrace rather than copying it out of
the process sigcontext.

After this, it turns out that arch/um/include/skas/mode-skas.h is almost
completely unneeded.  The declarations in it are variables which either don't
exist or which don't have global scope.  The one exception is
kill_off_processes_skas.  If that's removed, this header can be deleted.

This uncovered a bug in user.h, which wasn't correctly making sure that a
size_t definition was available to both userspace and kernelspace files.

Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5c8aacea

arch/um/include/os.h

+2 −0
Original line number Diff line number Diff line
@@ -307,6 +307,8 @@ extern int protect(struct mm_id * mm_idp, unsigned long addr, 
extern int is_skas_winch(int pid, int fd, void *data);

extern int start_userspace(unsigned long stub_stack);

extern int copy_context_skas0(unsigned long stack, int pid);

extern void save_registers(int pid, union uml_pt_regs *regs);

extern void restore_registers(int pid, union uml_pt_regs *regs);

extern void userspace(union uml_pt_regs *regs);

extern void map_stub_pages(int fd, unsigned long code,

			   unsigned long data, unsigned long stack);

arch/um/include/registers.h

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ extern int restore_fp_registers(int pid, unsigned long *fp_regs); 
extern void save_registers(int pid, union uml_pt_regs *regs);

extern void restore_registers(int pid, union uml_pt_regs *regs);

extern void init_registers(int pid);

extern void get_safe_registers(unsigned long * regs, unsigned long * fp_regs);

extern void get_safe_registers(unsigned long *regs);

extern unsigned long get_thread_reg(int reg, jmp_buf *buf);



#endif

arch/um/include/skas/mode-skas.h

+1 −8
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)

 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)

 * Licensed under the GPL

 */



#ifndef __MODE_SKAS_H__

#define __MODE_SKAS_H__



#include <sysdep/ptrace.h>



extern unsigned long exec_regs[];

extern unsigned long exec_fp_regs[];

extern unsigned long exec_fpx_regs[];

extern int have_fpx_regs;



extern void kill_off_processes_skas(void);



#endif

arch/um/include/sysdep-i386/ptrace.h

+0 −11
Original line number Diff line number Diff line
@@ -219,14 +219,3 @@ struct syscall_args { 
        CHOOSE_MODE((&(r)->tt.faultinfo), (&(r)->skas.faultinfo))



#endif
 


/*

 * 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/include/user.h

+5 −3
Original line number Diff line number Diff line
@@ -14,10 +14,12 @@ 
 */

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))



/*

 * This will provide the size_t definition in both kernel and userspace builds

 */

/* This is to get size_t */

#ifdef __KERNEL__

#include <linux/types.h>

#else

#include <stddef.h>

#endif



extern void panic(const char *fmt, ...)

	__attribute__ ((format (printf, 1, 2)));

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