Commit d04668a7 authored by Jamie Lokier's avatar Jamie Lokier Committed by Linus Torvalds

[PATCH] Common PROT_xxx -> VM_xxx mapping

This moves the mapping of PROT_* bits to VM_* bits from mmap.c to the
common header file <linux/mman.h>.  The mapping is needed for mprotect
too.
parent a1f6ff21
......@@ -2,6 +2,7 @@
#define _LINUX_MMAN_H
#include <linux/config.h>
#include <linux/mm.h>
#include <asm/atomic.h>
#include <asm/mman.h>
......@@ -27,4 +28,32 @@ static inline void vm_unacct_memory(long pages)
vm_acct_memory(-pages);
}
/* Optimisation macro. */
#define _calc_vm_trans(x,bit1,bit2) \
((bit1) <= (bit2) ? ((x) & (bit1)) * ((bit2) / (bit1)) \
: ((x) & (bit1)) / ((bit1) / (bit2)))
/*
* Combine the mmap "prot" argument into "vm_flags" used internally.
*/
static inline unsigned long
calc_vm_prot_bits(unsigned long prot)
{
return _calc_vm_trans(prot, PROT_READ, VM_READ ) |
_calc_vm_trans(prot, PROT_WRITE, VM_WRITE) |
_calc_vm_trans(prot, PROT_EXEC, VM_EXEC );
}
/*
* Combine the mmap "flags" argument into "vm_flags" used internally.
*/
static inline unsigned long
calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
_calc_vm_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE) |
_calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
}
#endif /* _LINUX_MMAN_H */
......@@ -136,29 +136,6 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
return retval;
}
/* Combine the mmap "prot" and "flags" argument into one "vm_flags" used
* internally. Essentially, translate the "PROT_xxx" and "MAP_xxx" bits
* into "VM_xxx".
*/
static inline unsigned long
calc_vm_flags(unsigned long prot, unsigned long flags)
{
#define _trans(x,bit1,bit2) \
((bit1==bit2)?(x&bit1):(x&bit1)?bit2:0)
unsigned long prot_bits, flag_bits;
prot_bits =
_trans(prot, PROT_READ, VM_READ) |
_trans(prot, PROT_WRITE, VM_WRITE) |
_trans(prot, PROT_EXEC, VM_EXEC);
flag_bits =
_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN) |
_trans(flags, MAP_DENYWRITE, VM_DENYWRITE) |
_trans(flags, MAP_EXECUTABLE, VM_EXECUTABLE);
return prot_bits | flag_bits;
#undef _trans
}
#ifdef DEBUG_MM_RB
static int browse_rb(struct rb_node * rb_node) {
int i = 0;
......@@ -500,8 +477,8 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
* to. we assume access permissions have been handled by the open
* of the memory object, so we don't do any here.
*/
vm_flags = calc_vm_flags(prot,flags) | mm->def_flags |
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
if (flags & MAP_LOCKED) {
if (!capable(CAP_IPC_LOCK))
......
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