Commit 42a2b54c authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: clean up TASK_SIZE usage 



Clean up the calculation and use of the usable address space size on the host.

task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR.  get_kmem_end and set_task_sizes_skas are also gone.

host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.

STACK_TOP is now TASK_SIZE minus the two stub pages.

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 b7c000cb

arch/um/include/as-layout.h

+13 −2
Original line number Diff line number Diff line
@@ -29,9 +29,20 @@ 
#define _AC(X, Y)	__AC(X, Y)

#endif



/*

 * The "- 1"'s are to avoid gcc complaining about integer overflows

 * and unrepresentable decimal constants.  With 3-level page tables,

 * TASK_SIZE is 0x80000000, which gets turned into its signed decimal

 * equivalent in asm-offsets.s.  gcc then complains about that being

 * unsigned only in C90.  To avoid that, UM_TASK_SIZE is defined as

 * TASK_SIZE - 1.  To compensate, we need to add the 1 back here.

 * However, adding it back to UM_TASK_SIZE produces more gcc

 * complaints.  So, I adjust the thing being subtracted from

 * UM_TASK_SIZE instead.  Bah.

 */

#define STUB_CODE _AC((unsigned long), \

		      UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)

#define STUB_DATA _AC((unsigned long), UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)

		      UM_TASK_SIZE - (2 * UM_KERN_PAGE_SIZE - 1))

#define STUB_DATA _AC((unsigned long), UM_TASK_SIZE - (UM_KERN_PAGE_SIZE - 1))

#define STUB_START _AC(, STUB_CODE)



#ifndef __ASSEMBLY__

arch/um/include/common-offsets.h

+3 −0
Original line number Diff line number Diff line
@@ -39,3 +39,6 @@ DEFINE(UM_HZ, HZ); 
DEFINE(UM_USEC_PER_SEC, USEC_PER_SEC);

DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);

DEFINE(UM_NSEC_PER_USEC, NSEC_PER_USEC);



/* See as-layout.h for an explanation of the "- 1".  Bah. */

DEFINE(UM_TASK_SIZE, TASK_SIZE - 1);

arch/um/include/mem_user.h

+0 −4
Original line number Diff line number Diff line
@@ -46,9 +46,6 @@ extern int iomem_size; 


#define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))



extern unsigned long host_task_size;

extern unsigned long task_size;



extern int init_mem_user(void);

extern void setup_memory(void *entry);

extern unsigned long find_iomem(char *driver, unsigned long *len_out);
@@ -62,6 +59,5 @@ extern unsigned long phys_offset(unsigned long phys); 
extern void unmap_physmem(void);

extern void map_memory(unsigned long virt, unsigned long phys,

		       unsigned long len, int r, int w, int x);

extern unsigned long get_kmem_end(void);



#endif

arch/um/kernel/exec.c

+1 −1
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ 
void flush_thread(void)

{

	void *data = NULL;

	unsigned long end = proc_mm ? task_size : STUB_START;

	unsigned long end = proc_mm ? TASK_SIZE : STUB_START;

	int ret;



	arch_flush_thread(&current->thread.arch);

arch/um/kernel/ksyms.c

+0 −3
Original line number Diff line number Diff line
@@ -18,11 +18,8 @@ EXPORT_SYMBOL(set_signals); 
EXPORT_SYMBOL(get_signals);

EXPORT_SYMBOL(kernel_thread);

EXPORT_SYMBOL(sys_waitpid);

EXPORT_SYMBOL(task_size);

EXPORT_SYMBOL(flush_tlb_range);

EXPORT_SYMBOL(host_task_size);

EXPORT_SYMBOL(arch_validate);

EXPORT_SYMBOL(get_kmem_end);



EXPORT_SYMBOL(high_physmem);

EXPORT_SYMBOL(empty_zero_page);

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