Hi Bob,
On 06/10/2011 03:39 PM, Bob Liu wrote:
Hi, Greg
On Fri, Jun 10, 2011 at 11:51 AM, Greg Ungerer<gerg@xxxxxxxxxxxx> wrote:
Hi Bob,
On 09/06/11 20:30, Bob Liu wrote:
On Wed, Jun 8, 2011 at 6:19 PM, Greg Ungerer<gerg@xxxxxxxxxxxx> áwrote:
When booting on a ColdFire (m68knommu) target the init process (or
there abouts at least) fails. Last console messages are:
...
VFS: Mounted root (romfs filesystem) readonly on device 31:0.
Freeing unused kernel memory: 52k freed (0x401aa000 - 0x401b6000)
Unable to mmap process text, errno 22
Oh, bad news. I will try to reproduce it on my board.
If you are free please enable debug in nommu.c and then we can see
what
caused the problem.
Yep, with debug on:
¡...
VFS: Mounted root (romfs filesystem) readonly on device 31:0.
Freeing unused kernel memory: 52k freed (0x4018c000 - 0x40198000)
==> á├Ãdo_mmap_pgoff(,0,6780,5,1002,0)
<== do_mmap_pgoff() = -22
Unable to mmap process text, errno 22
Since I can't reproduce this problem, could you please attach the
whole dmesg log with nommu debug on or
you can step into to see why errno 22 is returned, is it returned by
do_mmap_private()?
There was no other debug messages with debug turned on in nommu.c.
(I can give you the boot msgs before this if you want, but there
was no nommu.c debug in it).
But I did trace it into do_mmap_pgoff() to see what was failing.
It fails based on the return value from:
addr = file->f_op->get_unmapped_area(file, addr, len,
pgoff, flags);
Thanks for this information.
But it's a callback function. I still can't know what's the problem maybe.
Would you do me a favor to do more trace to see where it callback to,
fs or some driver etc..?
Its calling to romfs_get_unmapped_area() [fs/romfs/mmap-nommu.c]. It is
being called with:
áromfs_get_unmapped_area(addr=0,len=7000,pgoff=0,flags=1002)
This is failing the first size check because isize comes back
as 0x6ca8, and this is smaller then len (0x7000). Thus returning
-EINVAL.
I look into file fs/romfs/mmap-nommu.c based on your trace.
In my opinion, romfs_get_unmapped_area() in mmap-nommu.c is buggy.
Would you please try below commit.
Sure thing. I am away for the next couple of days, so I am
not going to be able to try it until Tuesday. I'll let you
know how it goes then.
Regards
Greg
Thanks a lot.
from 786add5286ffb476807cb198d7b2c5455e9fb533 Mon Sep 17 00:00:00 2001
From: Bob Liu<lliubbo@xxxxxxxxx>
Date: Fri, 10 Jun 2011 13:34:48 +0800
Subject: [PATCH] romfs: fix romfs_get_unmapped_area() param check
romfs_get_unmapped_area() check len param without considering PAGE_ALIGN which
will cause do_mmap_pgoff() return -EINVAL error after commit f67d9b1576c.
This patch fix the param check by changing it to the same way as function
ramfs_nommu_get_unmapped_area() did in ramfs/file-nommu.c.
Signed-off-by: Bob Liu<lliubbo@xxxxxxxxx>
---
fs/romfs/mmap-nommu.c | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index f0511e8..eed9942 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -27,14 +27,18 @@ static unsigned long
romfs_get_unmapped_area(struct file *file,
{
struct inode *inode = file->f_mapping->host;
struct mtd_info *mtd = inode->i_sb->s_mtd;
- unsigned long isize, offset;
+ unsigned long isize, offset, maxpages, lpages;
if (!mtd)
goto cant_map_directly;
+ /* the mapping mustn't extend beyond the EOF */
+ lpages = (len + PAGE_SIZE - 1)>> PAGE_SHIFT;
isize = i_size_read(inode);
offset = pgoff<< PAGE_SHIFT;
- if (offset> isize || len> isize || offset> isize - len)
+
+ maxpages = (isize + PAGE_SIZE - 1)>> PAGE_SHIFT;
+ if ((pgoff>= maxpages) || (maxpages - pgoff< lpages))
return (unsigned long) -EINVAL;
/* we need to call down to the MTD layer to do the actual mapping */
--
1.6.3.3
That code is trying to map the contents of the file /bin/init
directly from the romfs filesystem (which is in RAM). The init
binary is 0x6ca8 bytes in size (that is the isize above).
--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@xxxxxxxxxxxx
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close, FAX: +61 7 3891 3630
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com
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