This is a note to let you know that I've just added the patch titled
staging: tidspbridge: protect dmm_map properly
to the 2.6.37-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
staging-tidspbridge-protect-dmm_map-properly.patch
and it can be found in the queue-2.6.37 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From ab42abf33a3efdf754710a0a513c00c40854cd61 Mon Sep 17 00:00:00 2001
From: Felipe Contreras <[email protected]>
Date: Fri, 11 Mar 2011 18:29:06 -0600
Subject: staging: tidspbridge: protect dmm_map properly
From: Felipe Contreras <[email protected]>
commit ab42abf33a3efdf754710a0a513c00c40854cd61 upstream.
We need to protect not only the dmm_map list, but the individual
map_obj's, otherwise, we might be building the scatter-gather list with
garbage. So, use the existing proc_lock for that.
I observed race conditions which caused kernel panics while running
stress tests, also, Tuomas Kulve found it happening quite often in
Gumstix Over. This patch fixes those.
Cc: Tuomas Kulve <[email protected]>
Signed-off-by: Felipe Contreras <[email protected]>
Signed-off-by: Omar Ramirez Luna <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/staging/tidspbridge/rmgr/proc.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
--- a/drivers/staging/tidspbridge/rmgr/proc.c
+++ b/drivers/staging/tidspbridge/rmgr/proc.c
@@ -781,12 +781,14 @@ int proc_begin_dma(void *hprocessor, voi
(u32)pmpu_addr,
ul_size, dir);
+ mutex_lock(&proc_lock);
+
/* find requested memory are in cached mapping information */
map_obj = find_containing_mapping(pr_ctxt, (u32) pmpu_addr, ul_size);
if (!map_obj) {
pr_err("%s: find_containing_mapping failed\n", __func__);
status = -EFAULT;
- goto err_out;
+ goto no_map;
}
if (memory_give_ownership(map_obj, (u32) pmpu_addr, ul_size, dir)) {
@@ -795,6 +797,8 @@ int proc_begin_dma(void *hprocessor, voi
status = -EFAULT;
}
+no_map:
+ mutex_unlock(&proc_lock);
err_out:
return status;
@@ -819,21 +823,24 @@ int proc_end_dma(void *hprocessor, void
(u32)pmpu_addr,
ul_size, dir);
+ mutex_lock(&proc_lock);
+
/* find requested memory are in cached mapping information */
map_obj = find_containing_mapping(pr_ctxt, (u32) pmpu_addr, ul_size);
if (!map_obj) {
pr_err("%s: find_containing_mapping failed\n", __func__);
status = -EFAULT;
- goto err_out;
+ goto no_map;
}
if (memory_regain_ownership(map_obj, (u32) pmpu_addr, ul_size, dir)) {
pr_err("%s: InValid address parameters %p %x\n",
__func__, pmpu_addr, ul_size);
status = -EFAULT;
- goto err_out;
}
+no_map:
+ mutex_unlock(&proc_lock);
err_out:
return status;
}
@@ -1726,9 +1733,8 @@ int proc_un_map(void *hprocessor, void *
(p_proc_object->hbridge_context, va_align, size_align);
}
- mutex_unlock(&proc_lock);
if (status)
- goto func_end;
+ goto unmap_failed;
/*
* A successful unmap should be followed by removal of map_obj
@@ -1737,6 +1743,9 @@ int proc_un_map(void *hprocessor, void *
*/
remove_mapping_information(pr_ctxt, (u32) map_addr, size_align);
+unmap_failed:
+ mutex_unlock(&proc_lock);
+
func_end:
dev_dbg(bridge, "%s: hprocessor: 0x%p map_addr: 0x%p status: 0x%x\n",
__func__, hprocessor, map_addr, status);
Patches currently in stable-queue which might be from
[email protected] are
queue-2.6.37/staging-tidspbridge-protect-dmm_map-properly.patch
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