linux/arch
Ingo Molnar f022bfd582 x86: PAT fix
Adrian Bunk noticed the following Coverity report:

> Commit e7f260a276
> (x86: PAT use reserve free memtype in mmap of /dev/mem)
> added the following gem to arch/x86/mm/pat.c:
>
> <--  snip  -->
>
> ...
> int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
>                                 unsigned long size, pgprot_t *vma_prot)
> {
>         u64 offset = ((u64) pfn) << PAGE_SHIFT;
>         unsigned long flags = _PAGE_CACHE_UC_MINUS;
>         unsigned long ret_flags;
> ...
> ...  (nothing that touches ret_flags)
> ...
>         if (flags != _PAGE_CACHE_UC_MINUS) {
>                 retval = reserve_memtype(offset, offset + size, flags, NULL);
>         } else {
>                 retval = reserve_memtype(offset, offset + size, -1, &ret_flags);
>         }
>
>         if (retval < 0)
>                 return 0;
>
>         flags = ret_flags;
>
>         if (pfn <= max_pfn_mapped &&
>             ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
>                 free_memtype(offset, offset + size);
>                 printk(KERN_INFO
>                 "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
>                         current->comm, current->pid,
>                         cattr_name(flags),
>                         offset, offset + size);
>                 return 0;
>         }
>
>         *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
>                              flags);
>         return 1;
> }
>
> <--  snip  -->
>
> If (flags != _PAGE_CACHE_UC_MINUS) we pass garbage from the stack to
> ioremap_change_attr() and/or __pgprot().
>
> Spotted by the Coverity checker.

the fix simplifies the code as we get rid of the 'ret_flags'
complication.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:15:16 -07:00
..
alpha alpha: unbreak OSF/1 (a.out) binaries 2008-04-24 08:35:47 -07:00
arm Merge branch 'irq-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6 2008-04-24 08:42:21 -07:00
avr32 avr32: Add hardware power-down function call 2008-04-19 20:40:11 -04:00
blackfin [Blackfin] arch: add include/boot .gitignore files 2008-04-25 08:29:11 +08:00
cris Generic semaphore implementation 2008-04-17 10:42:34 -04:00
frv frv: unexport kmap_atomic_to_page 2008-04-21 16:03:13 -07:00
h8300 Generic semaphore implementation 2008-04-17 10:42:34 -04:00
ia64 KVM: add ioctls to save/store mpstate 2008-04-27 18:21:16 +03:00
m32r Generic semaphore implementation 2008-04-17 10:42:34 -04:00
m68k arch: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:14:49 -04:00
m68knommu Generic semaphore implementation 2008-04-17 10:42:34 -04:00
mips arch: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:14:49 -04:00
mn10300 PCI: remove initial bios sort of PCI devices on x86 2008-04-20 21:46:58 -07:00
parisc Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6 2008-04-21 15:58:35 -07:00
powerpc KVM: ppc: PowerPC 440 KVM implementation 2008-04-27 18:21:39 +03:00
ppc [POWERPC] Add strncmp to arch/ppc 2008-04-24 20:57:34 +10:00
s390 KVM: add ioctls to save/store mpstate 2008-04-27 18:21:16 +03:00
sh Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6 2008-04-21 15:58:35 -07:00
sparc sparc: cleanup after SunOS binary emulation removal 2008-04-23 23:32:18 -07:00
sparc64 [SPARC64]: Wrap SMP IPIs with irq_enter()/irq_exit(). 2008-04-25 03:11:37 -07:00
um x86, bitops: select the generic bitmap search functions 2008-04-26 19:21:17 +02:00
v850 arch: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:14:49 -04:00
x86 x86: PAT fix 2008-04-28 08:15:16 -07:00
xtensa Generic semaphore implementation 2008-04-17 10:42:34 -04:00
.gitignore arch: Ignore arch/i386 and arch/x86_64 2008-01-19 21:29:39 -08:00
Kconfig Kprobes: indicate kretprobe support in Kconfig 2008-03-04 16:35:11 -08:00