Andrew Morton wrote:
>
> Daniel Jacobowitz wrote:
> >
> > Frame buffers aren't reliable marked VM_IO when mapped, currently. Ben
> > H. said he was going to push a fix for this at least to the PPC trees
> > today or tomorrow.
>
> They are now, I hope. I fixed that in 2.4.18-pre2.
> drivers/video/fbmem.c:fb_mmap() marks the vma as
> VM_IO for all architectures. But perhaps I missed some;
> an audit is needed in there, which I'll do.
I lied. Linus applied it, but not, it seems, Marcelo.
So. Here's a patch.
It marks all framebuffer mappings as VM_IO. This prevents
kernel deadlocks which can occur when a program which
has a framebuffer mapping attempts to dump core.
It also allows get_user_pages() to detect and skip these
IO mappings, so ptrace, O_DIRECT, etc will not permit
I/O against these mappings.
I've Cc'ed linux-fbdev-devel. Could someone please
review?
--- linux-2.4.18-pre7/drivers/video/acornfb.c Thu Nov 22 23:02:58 2001
+++ linux-akpm/drivers/video/acornfb.c Mon Jan 28 14:00:21 2002
@@ -1139,9 +1139,6 @@ acornfb_mmap(struct fb_info *info, struc
off += start;
vma->vm_pgoff = off >> PAGE_SHIFT;
- /* This is an IO map - tell maydump to skip this VMA */
- vma->vm_flags |= VM_IO;
-
#ifdef CONFIG_CPU_32
pgprot_val(vma->vm_page_prot) &= ~L_PTE_CACHEABLE;
#endif
--- linux-2.4.18-pre7/drivers/video/igafb.c Thu Nov 22 23:02:58 2001
+++ linux-akpm/drivers/video/igafb.c Mon Jan 28 14:02:10 2002
@@ -293,8 +293,6 @@ static int igafb_mmap(struct fb_info *in
if (!map_size)
return -EINVAL;
- vma->vm_flags |= VM_IO;
-
if (!fb->mmaped) {
int lastconsole = 0;
--- linux-2.4.18-pre7/drivers/video/sgivwfb.c Thu Nov 22 23:02:58 2001
+++ linux-akpm/drivers/video/sgivwfb.c Mon Jan 28 14:02:49 2002
@@ -846,7 +846,6 @@ static int sgivwfb_mmap(struct fb_info *
return -EINVAL;
offset += sgivwfb_mem_phys;
pgprot_val(vma->vm_page_prot) = pgprot_val(vma->vm_page_prot) | _PAGE_PCD;
- vma->vm_flags |= VM_IO;
if (remap_page_range(vma->vm_start, offset, size, vma->vm_page_prot))
return -EAGAIN;
vma->vm_file = file;
--- linux-2.4.18-pre7/drivers/video/fbmem.c Fri Dec 21 11:19:14 2001
+++ linux-akpm/drivers/video/fbmem.c Mon Jan 28 14:07:08 2002
@@ -543,6 +543,8 @@ fb_mmap(struct file *file, struct vm_are
lock_kernel();
res = fb->fb_mmap(info, file, vma);
unlock_kernel();
+ /* This is an IO map - tell maydump to skip this VMA */
+ vma->vm_flags |= VM_IO;
return res;
}
@@ -576,12 +578,13 @@ fb_mmap(struct file *file, struct vm_are
return -EINVAL;
off += start;
vma->vm_pgoff = off >> PAGE_SHIFT;
+ /* This is an IO map - tell maydump to skip this VMA */
+ vma->vm_flags |= VM_IO;
#if defined(__sparc_v9__)
vma->vm_flags |= (VM_SHM | VM_LOCKED);
if (io_remap_page_range(vma->vm_start, off,
vma->vm_end - vma->vm_start, vma->vm_page_prot, 0))
return -EAGAIN;
- vma->vm_flags |= VM_IO;
#else
#if defined(__mc68000__)
#if defined(CONFIG_SUN3)
@@ -607,8 +610,6 @@ fb_mmap(struct file *file, struct vm_are
pgprot_val(vma->vm_page_prot) |= _CACHE_UNCACHED;
#elif defined(__arm__)
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- /* This is an IO map - tell maydump to skip this VMA */
- vma->vm_flags |= VM_IO;
#elif defined(__sh__)
pgprot_val(vma->vm_page_prot) &= ~_PAGE_CACHABLE;
#else
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Jan 31 2002 - 21:00:54 EST