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Commit 3b52166c authored by Paolo 'Blaisorblade' Giarrusso's avatar Paolo 'Blaisorblade' Giarrusso Committed by Linus Torvalds
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[PATCH] uml: fault handler micro-cleanups 



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: default avatarPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 1e40cd38

arch/um/kernel/trap_kern.c

+13 −15
Original line number Original line Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include "mem.h"

#include "mem.h"

#include "mem_kern.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 handle_page_fault(unsigned long address, unsigned long ip, 

		      int is_write, int is_user, int *code_out)

		      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;

	pud_t *pud;

	pmd_t *pmd;

	pmd_t *pmd;

	pte_t *pte;

	pte_t *pte;

	unsigned long page;

	int err = -EFAULT;

	int err = -EFAULT;





	*code_out = SEGV_MAPERR;

	*code_out = SEGV_MAPERR;
@@ -60,7 +60,6 @@ int handle_page_fault(unsigned long address, unsigned long ip, 
        if(!(vma->vm_flags & (VM_READ | VM_EXEC)))

        if(!(vma->vm_flags & (VM_READ | VM_EXEC)))

                goto out;

                goto out;





	page = address & PAGE_MASK;

	do {

	do {

survive:

survive:

		switch (handle_mm_fault(mm, vma, address, is_write)){

		switch (handle_mm_fault(mm, vma, address, is_write)){
@@ -79,15 +78,15 @@ int handle_page_fault(unsigned long address, unsigned long ip, 
		default:

		default:

			BUG();

			BUG();

		}

		}

		pgd = pgd_offset(mm, page);

		pgd = pgd_offset(mm, address);

		pud = pud_offset(pgd, page);

		pud = pud_offset(pgd, address);

		pmd = pmd_offset(pud, page);

		pmd = pmd_offset(pud, address);

		pte = pte_offset_kernel(pmd, page);

		pte = pte_offset_kernel(pmd, address);

	} while(!pte_present(*pte));

	} while(!pte_present(*pte));

	err = 0;

	err = 0;

	*pte = pte_mkyoung(*pte);

	*pte = pte_mkyoung(*pte);

	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);

	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);

	flush_tlb_page(vma, page);

	flush_tlb_page(vma, address);

out:

out:

	up_read(&mm->mmap_sem);

	up_read(&mm->mmap_sem);

	return(err);

	return(err);
@@ -151,12 +150,11 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc) 
		si.si_addr = (void *)address;

		si.si_addr = (void *)address;

                current->thread.arch.faultinfo = fi;

                current->thread.arch.faultinfo = fi;

		force_sig_info(SIGBUS, &si, current);

		force_sig_info(SIGBUS, &si, current);

	}

	} else if (err == -ENOMEM) {

	else if(err == -ENOMEM){

		printk("VM: killing process %s\n", current->comm);

		printk("VM: killing process %s\n", current->comm);

		do_exit(SIGKILL);

		do_exit(SIGKILL);

	}

	} else {

	else {

		BUG_ON(err != -EFAULT);

		si.si_signo = SIGSEGV;

		si.si_signo = SIGSEGV;

		si.si_addr = (void *) address;

		si.si_addr = (void *) address;

                current->thread.arch.faultinfo = fi;

                current->thread.arch.faultinfo = fi;