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[PATCH] uml: fault handler micro-cleanups

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Avoid chomping low bits of address for functions doing it by themselves,
fix whitespace, add a correctness checking.

I did this for remap-file-pages protection support, it was useful on its
own too.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Paolo 'Blaisorblade' Giarrusso 2005-09-03 15:57:26 -07:00 committed by Linus Torvalds
parent 1e40cd383c
commit 3b52166cf7
1 changed files with 13 additions and 15 deletions
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28
arch/um/kernel/trap_kern.c
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@ -26,6 +26,7 @@
#include "mem.h"
#include "mem_kern.h"
/* Note this is constrained to return 0, -EFAULT, -EACCESS, -ENOMEM by segv(). */
int handle_page_fault(unsigned long address, unsigned long ip,
int is_write, int is_user, int *code_out)
{
@ -35,7 +36,6 @@ int handle_page_fault(unsigned long address, unsigned long ip,
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long page;
int err = -EFAULT;
*code_out = SEGV_MAPERR;
@ -52,7 +52,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
else if(expand_stack(vma, address))
goto out;
good_area:
good_area:
*code_out = SEGV_ACCERR;
if(is_write && !(vma->vm_flags & VM_WRITE))
goto out;
@ -60,9 +60,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto out;
page = address & PAGE_MASK;
do {
survive:
survive:
switch (handle_mm_fault(mm, vma, address, is_write)){
case VM_FAULT_MINOR:
current->min_flt++;
@ -79,16 +78,16 @@ int handle_page_fault(unsigned long address, unsigned long ip,
default:
BUG();
}
pgd = pgd_offset(mm, page);
pud = pud_offset(pgd, page);
pmd = pmd_offset(pud, page);
pte = pte_offset_kernel(pmd, page);
pgd = pgd_offset(mm, address);
pud = pud_offset(pgd, address);
pmd = pmd_offset(pud, address);
pte = pte_offset_kernel(pmd, address);
} while(!pte_present(*pte));
err = 0;
*pte = pte_mkyoung(*pte);
if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
flush_tlb_page(vma, page);
out:
flush_tlb_page(vma, address);
out:
up_read(&mm->mmap_sem);
return(err);
@ -144,19 +143,18 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
address, ip);
if(err == -EACCES){
if (err == -EACCES) {
si.si_signo = SIGBUS;
si.si_errno = 0;
si.si_code = BUS_ADRERR;
si.si_addr = (void *)address;
current->thread.arch.faultinfo = fi;
force_sig_info(SIGBUS, &si, current);
}
else if(err == -ENOMEM){
} else if (err == -ENOMEM) {
printk("VM: killing process %s\n", current->comm);
do_exit(SIGKILL);
}
else {
} else {
BUG_ON(err != -EFAULT);
si.si_signo = SIGSEGV;
si.si_addr = (void *) address;
current->thread.arch.faultinfo = fi;