[PATCH] iSeries: Don't leak if allocations fail in mf_getSrcHistory

Hi,

If memory is tight and a dynamic allocation fails there's no reason to 
make a bad situation worse by leaking memory.

mf_getSrcHistory potentially leaks pages[0-3]. I believe the right thing 
to do is to free that memory again before returning -ENOMEM - which is 
what this patch does.

I realize that the function is under '#if 0' so this probably doesn't 
matter much, but I assume that the function is still there for a reason 
(but I could be wrong, I don't know the powerpc code).
Anyway, I suggest we remove the leak.

Please keep me on CC when replying.


Signed-off-by: Jesper Juhl <redacted>
---
 mf.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/iseries/mf.c b/arch/powerpc/platforms/iseries/mf.c
index 42d0a88..f67522a 100644
--- a/arch/powerpc/platforms/iseries/mf.c
+++ b/arch/powerpc/platforms/iseries/mf.c

@@ -1058,8 +1058,13 @@ static void mf_getSrcHistory(char *buffer, int size)
 	pages[2] = kmalloc(4096, GFP_ATOMIC);
 	pages[3] = kmalloc(4096, GFP_ATOMIC);
 	if ((ev == NULL) || (pages[0] == NULL) || (pages[1] == NULL)
-			 || (pages[2] == NULL) || (pages[3] == NULL))
+			 || (pages[2] == NULL) || (pages[3] == NULL)) {
+		kfree(pages[3]);
+		kfree(pages[2]);
+		kfree(pages[1]);
+		kfree(pages[0]);
 		return -ENOMEM;
+	}
 
 	return_stuff.xType = 0;
 	return_stuff.xRc = 0;

-- 
Jesper Juhl <jj@chaosbits.net>             http://www.chaosbits.net/
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On Sat, 2010-10-30 at 19:20 +0200, Jesper Juhl wrote:

Hi,

If memory is tight and a dynamic allocation fails there's no reason to 
make a bad situation worse by leaking memory.

mf_getSrcHistory potentially leaks pages[0-3]. I believe the right thing 
to do is to free that memory again before returning -ENOMEM - which is 
what this patch does.

I realize that the function is under '#if 0' so this probably doesn't 
matter much, but I assume that the function is still there for a reason 
(but I could be wrong, I don't know the powerpc code).
Anyway, I suggest we remove the leak.

Stephen is the iSeries maintainer, and I think he #if 0'ed the code. But
I don't think it will ever be un-ifdef'ed, so should probably just be
removed.

cheers

Hi Jesper,

On Mon, 01 Nov 2010 22:10:42 +1100 Michael Ellerman [off-list ref] wrote:

On Sat, 2010-10-30 at 19:20 +0200, Jesper Juhl wrote:

quoted

If memory is tight and a dynamic allocation fails there's no reason to 
make a bad situation worse by leaking memory.

mf_getSrcHistory potentially leaks pages[0-3]. I believe the right thing 
to do is to free that memory again before returning -ENOMEM - which is 
what this patch does.

I realize that the function is under '#if 0' so this probably doesn't 
matter much, but I assume that the function is still there for a reason 
(but I could be wrong, I don't know the powerpc code).
Anyway, I suggest we remove the leak.

Stephen is the iSeries maintainer, and I think he #if 0'ed the code. But
I don't think it will ever be un-ifdef'ed, so should probably just be
removed.

Well, only unofficially iseries maintainer :-)

Yes, just remove the whole function ... it was never used and never will
be.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

On Tue, 2 Nov 2010, Stephen Rothwell wrote:

Hi Jesper,

On Mon, 01 Nov 2010 22:10:42 +1100 Michael Ellerman [off-list ref] wrote:

quoted

On Sat, 2010-10-30 at 19:20 +0200, Jesper Juhl wrote:

quoted

If memory is tight and a dynamic allocation fails there's no reason to 
make a bad situation worse by leaking memory.

mf_getSrcHistory potentially leaks pages[0-3]. I believe the right thing 
to do is to free that memory again before returning -ENOMEM - which is 
what this patch does.

I realize that the function is under '#if 0' so this probably doesn't 
matter much, but I assume that the function is still there for a reason 
(but I could be wrong, I don't know the powerpc code).
Anyway, I suggest we remove the leak.

Stephen is the iSeries maintainer, and I think he #if 0'ed the code. But
I don't think it will ever be un-ifdef'ed, so should probably just be
removed.

Well, only unofficially iseries maintainer :-)

Yes, just remove the whole function ... it was never used and never will
be.

Done.

Remove unused function 'mf_getSrcHistory' (that will never be used ever 
according to Stephen Rothwell).

Signed-off-by: Jesper Juhl <redacted>
---
 mf.c |   46 ----------------------------------------------
 1 file changed, 46 deletions(-)

diff --git a/arch/powerpc/platforms/iseries/mf.c b/arch/powerpc/platforms/iseries/mf.c
index 42d0a88..56cfd8c 100644
--- a/arch/powerpc/platforms/iseries/mf.c
+++ b/arch/powerpc/platforms/iseries/mf.c

@@ -1045,52 +1045,6 @@ static const struct file_operations mf_side_proc_fops = {
 	.write		= mf_side_proc_write,
 };
 
-#if 0
-static void mf_getSrcHistory(char *buffer, int size)
-{
-	struct IplTypeReturnStuff return_stuff;
-	struct pending_event *ev = new_pending_event();
-	int rc = 0;
-	char *pages[4];
-
-	pages[0] = kmalloc(4096, GFP_ATOMIC);
-	pages[1] = kmalloc(4096, GFP_ATOMIC);
-	pages[2] = kmalloc(4096, GFP_ATOMIC);
-	pages[3] = kmalloc(4096, GFP_ATOMIC);
-	if ((ev == NULL) || (pages[0] == NULL) || (pages[1] == NULL)
-			 || (pages[2] == NULL) || (pages[3] == NULL))
-		return -ENOMEM;
-
-	return_stuff.xType = 0;
-	return_stuff.xRc = 0;
-	return_stuff.xDone = 0;
-	ev->event.hp_lp_event.xSubtype = 6;
-	ev->event.hp_lp_event.x.xSubtypeData =
-		subtype_data('M', 'F', 'V', 'I');
-	ev->event.data.vsp_cmd.xEvent = &return_stuff;
-	ev->event.data.vsp_cmd.cmd = 4;
-	ev->event.data.vsp_cmd.lp_index = HvLpConfig_getLpIndex();
-	ev->event.data.vsp_cmd.result_code = 0xFF;
-	ev->event.data.vsp_cmd.reserved = 0;
-	ev->event.data.vsp_cmd.sub_data.page[0] = iseries_hv_addr(pages[0]);
-	ev->event.data.vsp_cmd.sub_data.page[1] = iseries_hv_addr(pages[1]);
-	ev->event.data.vsp_cmd.sub_data.page[2] = iseries_hv_addr(pages[2]);
-	ev->event.data.vsp_cmd.sub_data.page[3] = iseries_hv_addr(pages[3]);
-	mb();
-	if (signal_event(ev) != 0)
-		return;
-
- 	while (return_stuff.xDone != 1)
- 		udelay(10);
- 	if (return_stuff.xRc == 0)
- 		memcpy(buffer, pages[0], size);
-	kfree(pages[0]);
-	kfree(pages[1]);
-	kfree(pages[2]);
-	kfree(pages[3]);
-}
-#endif
-
 static int mf_src_proc_show(struct seq_file *m, void *v)
 {
 #if 0
 

-- 
Jesper Juhl <jj@chaosbits.net>             http://www.chaosbits.net/
Plain text mails only, please      http://www.expita.com/nomime.html
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html

On Mon, 1 Nov 2010 21:06:23 +0100 (CET) Jesper Juhl [off-list ref] wrote:

Remove unused function 'mf_getSrcHistory' (that will never be used ever 
according to Stephen Rothwell).

Signed-off-by: Jesper Juhl <redacted>

Acked-by: Stephen Rothwell <redacted>

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

Hi Stephen,

On Tue, 2 Nov 2010, Stephen Rothwell wrote:

On Mon, 1 Nov 2010 21:06:23 +0100 (CET) Jesper Juhl [off-list ref] wrote:

quoted

Remove unused function 'mf_getSrcHistory' (that will never be used ever 
according to Stephen Rothwell).

Signed-off-by: Jesper Juhl <redacted>

Acked-by: Stephen Rothwell <redacted>

Ok, so if you are the (unofficial) iSeries maintainer and you don't merge 
the patch somewhere that'll eventually go up-stream, but just ACK it 
(thank you for that btw), then where do I send it to get it merged?

-- 
Jesper Juhl [off-list ref]             http://www.chaosbits.net/
Plain text mails only, please      http://www.expita.com/nomime.html
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html

On Mon, 2010-11-01 at 22:20 +0100, Jesper Juhl wrote:

Hi Stephen,

On Tue, 2 Nov 2010, Stephen Rothwell wrote:

quoted

On Mon, 1 Nov 2010 21:06:23 +0100 (CET) Jesper Juhl [off-list ref] wrote:

quoted

Remove unused function 'mf_getSrcHistory' (that will never be used ever 
according to Stephen Rothwell).

Signed-off-by: Jesper Juhl <redacted>

Acked-by: Stephen Rothwell <redacted>

Ok, so if you are the (unofficial) iSeries maintainer and you don't merge 
the patch somewhere that'll eventually go up-stream, but just ACK it 
(thank you for that btw), then where do I send it to get it merged?

Here. ie. linuxppc-dev.

But, while you're removing it you should remove the #if 0'ed callsite as
well, see mf_src_proc_show() in that file. :)

cheers

On Tue, 2 Nov 2010, Michael Ellerman wrote:

On Mon, 2010-11-01 at 22:20 +0100, Jesper Juhl wrote:

quoted

Hi Stephen,

On Tue, 2 Nov 2010, Stephen Rothwell wrote:

quoted

On Mon, 1 Nov 2010 21:06:23 +0100 (CET) Jesper Juhl [off-list ref] wrote:

quoted

Remove unused function 'mf_getSrcHistory' (that will never be used ever 
according to Stephen Rothwell).

Signed-off-by: Jesper Juhl <redacted>

Acked-by: Stephen Rothwell <redacted>

Ok, so if you are the (unofficial) iSeries maintainer and you don't merge 
the patch somewhere that'll eventually go up-stream, but just ACK it 
(thank you for that btw), then where do I send it to get it merged?

Here. ie. linuxppc-dev.

But, while you're removing it you should remove the #if 0'ed callsite as
well, see mf_src_proc_show() in that file. :)

Done. See patch below.


Remove unused function 'mf_getSrcHistory' (that will never be used 
ever according to Stephen Rothwell) and also remove most of (under 'if 
0') code from mf_src_proc_show() where the function was called.

Signed-off-by: Jesper Juhl <redacted>
---
 mf.c |   62 
--------------------------------------------------------------
 1 file changed, 62 deletions(-)

diff --git a/arch/powerpc/platforms/iseries/mf.c b/arch/powerpc/platforms/iseries/mf.c
index 42d0a88..b5e026b 100644
--- a/arch/powerpc/platforms/iseries/mf.c
+++ b/arch/powerpc/platforms/iseries/mf.c

@@ -1045,71 +1045,9 @@ static const struct file_operations mf_side_proc_fops = {
 	.write		= mf_side_proc_write,
 };
 
-#if 0
-static void mf_getSrcHistory(char *buffer, int size)
-{
-	struct IplTypeReturnStuff return_stuff;
-	struct pending_event *ev = new_pending_event();
-	int rc = 0;
-	char *pages[4];
-
-	pages[0] = kmalloc(4096, GFP_ATOMIC);
-	pages[1] = kmalloc(4096, GFP_ATOMIC);
-	pages[2] = kmalloc(4096, GFP_ATOMIC);
-	pages[3] = kmalloc(4096, GFP_ATOMIC);
-	if ((ev == NULL) || (pages[0] == NULL) || (pages[1] == NULL)
-			 || (pages[2] == NULL) || (pages[3] == NULL))
-		return -ENOMEM;
-
-	return_stuff.xType = 0;
-	return_stuff.xRc = 0;
-	return_stuff.xDone = 0;
-	ev->event.hp_lp_event.xSubtype = 6;
-	ev->event.hp_lp_event.x.xSubtypeData =
-		subtype_data('M', 'F', 'V', 'I');
-	ev->event.data.vsp_cmd.xEvent = &return_stuff;
-	ev->event.data.vsp_cmd.cmd = 4;
-	ev->event.data.vsp_cmd.lp_index = HvLpConfig_getLpIndex();
-	ev->event.data.vsp_cmd.result_code = 0xFF;
-	ev->event.data.vsp_cmd.reserved = 0;
-	ev->event.data.vsp_cmd.sub_data.page[0] = iseries_hv_addr(pages[0]);
-	ev->event.data.vsp_cmd.sub_data.page[1] = iseries_hv_addr(pages[1]);
-	ev->event.data.vsp_cmd.sub_data.page[2] = iseries_hv_addr(pages[2]);
-	ev->event.data.vsp_cmd.sub_data.page[3] = iseries_hv_addr(pages[3]);
-	mb();
-	if (signal_event(ev) != 0)
-		return;
-
- 	while (return_stuff.xDone != 1)
- 		udelay(10);
- 	if (return_stuff.xRc == 0)
- 		memcpy(buffer, pages[0], size);
-	kfree(pages[0]);
-	kfree(pages[1]);
-	kfree(pages[2]);
-	kfree(pages[3]);
-}
-#endif
-
 static int mf_src_proc_show(struct seq_file *m, void *v)
 {
-#if 0
-	int len;
-
-	mf_getSrcHistory(page, count);
-	len = count;
-	len -= off;
-	if (len < count) {
-		*eof = 1;
-		if (len <= 0)
-			return 0;
-	} else
-		len = count;
-	*start = page + off;
-	return len;
-#else
 	return 0;
-#endif
 }
 
 static int mf_src_proc_open(struct inode *inode, struct file *file)

-- 
Jesper Juhl <jj@chaosbits.net>             http://www.chaosbits.net/
Plain text mails only, please      http://www.expita.com/nomime.html
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html

On Fri, 5 Nov 2010, Jesper Juhl wrote:

PING.

Is this going to get merged somewhere or is there a problem?


-- 
Jesper Juhl [off-list ref]            http://www.chaosbits.net/
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On Thu, 2010-11-18 at 20:45 +0100, Jesper Juhl wrote:

On Fri, 5 Nov 2010, Jesper Juhl wrote:

quoted

 
 static int mf_src_proc_open(struct inode *inode, struct file *file)

PING.

Is this going to get merged somewhere or is there a problem?

Yes, no.

It won't get lost:
http://patchwork.ozlabs.org/patch/70201/

cheers

On Fri, 19 Nov 2010, Michael Ellerman wrote:

On Thu, 2010-11-18 at 20:45 +0100, Jesper Juhl wrote:

quoted

On Fri, 5 Nov 2010, Jesper Juhl wrote:

quoted

 
 static int mf_src_proc_open(struct inode *inode, struct file *file)

quoted

PING.

Is this going to get merged somewhere or is there a problem?

Yes, no.

It won't get lost:
http://patchwork.ozlabs.org/patch/70201/

Ok. Thank you for that bit of information. That was one place that I had 
no knowledge about what-so-ever, so I didn't look.

I will now rest happily in the knowledge that the patch is in good hands. 
Thanks.


-- 
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Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
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