All of lore.kernel.org
 help / color / mirror / Atom feed
* Re: [PATCH] powerpc/mpic: Fix memory leak of mpic on error paths
@ 2026-09-30 16:41 Jyoti Gupta
  0 siblings, 0 replies; 7+ messages in thread
From: Jyoti Gupta @ 2026-09-30 16:41 UTC (permalink / raw)
  To: linuxppc-dev, maddy, mpe, npiggin, chleroy, ritesh.list, sshegde,
	sourabhjain, amachhiw

On 2026-09-29 13:02, Amit Machhiwal wrote:
> Hi Jyoti,
> 
> For some reason, you response to this thread is not appearing on the 
> list.  I
> think you mail client is messing up the "In-Reply-To" information in 
> the
> header.  Fix look into fixing it.
> 
> For now, I'll qoute your reply here with my further response.
> 
Hello Amit ,

I'm not sure why my reply did not reach the list,but it is visible at 
the link below:
https://lore.kernel.org/all/e3c17fc50f7897b08fbd67a120087467@linux.ibm.com/

let me know if this looks fine.

> On 2026/09/24 03:05 PM, Amit Machhiwal wrote:
>> On 2026/09/24 12:00 PM, Jyoti Gupta wrote:
>> > mpic_alloc() allocates struct mpic (and optionally the protected
>> > sources bitmap) but does not free them when mpic_setup_error_int() or
>> > irq_domain_create_linear() fails, leaking the memory.
>> >
>> > Initialise mpic to NULL and free the bitmap and the mpic in the common
>> > error path before dropping the device node reference. The register
>> > mappings are not released here.
>> >
>> > Signed-off-by: Jyoti Gupta <jyoti@linux.ibm.com>
>> 
>> I see a couple of problems with this patch:
>> 
>> 1. The patch does not apply.  Both "git apply" and "git am" fail on 
>> this patch.
>>    I think the context lines around the irq_domain_create_linear() 
>> call have
>>    tabs converted to spaces, which causes the context match to fail.
>> 
>>       ❯ git apply 
>> ./20260924_jyoti_powerpc_mpic_fix_memory_leak_of_mpic_on_error_paths.mbx 
>> --check --verbose
>>       Checking patch arch/powerpc/sysdev/mpic.c...
>>       error: while searching for:
>>       						 intvec_top,
>>       						 &mpic_host_ops, mpic);
>> 
>>       	/*
>>       	 * FIXME: The code leaks the MPIC object and mappings here; 
>> this
>>       	 * is very unlikely to fail but it ought to be fixed anyways.
>>       	 */
>>       	if (mpic->irqhost == NULL)
>>       		goto err_of_node_put;
>> 
>> 
>>       error: patch failed: arch/powerpc/sysdev/mpic.c:1488
>>       error: arch/powerpc/sysdev/mpic.c: patch does not apply
>> 
>>    Please regenerate with:
>> 
>>      git format-patch -1
>> 
>>    and verify with:
>> 
>>      git apply --check <patch>
>> 
>>    before resending.
>> 
>> 2. The mpic_setup_error_int() leak is not actually fixed.  The commit 
>> message
>>    says both mpic_setup_error_int() and irq_domain_create_linear() 
>> failure paths
>>    are fixed, but the former still does a bare return NULL:
>> 
>>      if (fsl_version >= 0x401) {
>>          ret = mpic_setup_error_int(mpic, intvec_top - 13);
>>          if (ret)
>>              return NULL;   /* <-- still leaks mpic and 
>> mpic->protected */
>>      }
>> 
>>    This needs to become:
>> 
>>          if (ret)
>>              goto err_of_node_put;
>> 
>> Thanks,
>> Amit
>> 
>> > ---
>> >  arch/powerpc/sysdev/mpic.c | 9 ++++-----
>> >  1 file changed, 4 insertions(+), 5 deletions(-)
>> >
>> > diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
>> > index 6e8fa94985f3..e777b33f170d 100644
>> > --- a/arch/powerpc/sysdev/mpic.c
>> > +++ b/arch/powerpc/sysdev/mpic.c
>> > @@ -1221,7 +1221,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
>> >  				const char *name)
>> >  {
>> >  	int i, psize, intvec_top;
>> > -	struct mpic *mpic;
>> > +	struct mpic *mpic = NULL;
>> >  	u32 greg_feature;
>> >  	const char *vers;
>> >  	const u32 *psrc;
>> > @@ -1488,10 +1488,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
>> >  						 intvec_top,
>> >  						 &mpic_host_ops, mpic);
>> >
>> > -	/*
>> > -	 * FIXME: The code leaks the MPIC object and mappings here; this
>> > -	 * is very unlikely to fail but it ought to be fixed anyways.
>> > -	 */
>> >  	if (mpic->irqhost == NULL)
>> >  		goto err_of_node_put;
>> >
>> > @@ -1527,6 +1523,9 @@ struct mpic * __init mpic_alloc(struct device_node *node,
>> >  	return mpic;
>> >
>> >  err_of_node_put:
>> > +	if (mpic)
>> > +		bitmap_free(mpic->protected);
>> > +	kfree(mpic);
>> >  	of_node_put(node);
>> >  	return NULL;
>> >  }
>> > --
>> > 2.55.0
>> >
>> >
>> 
> 
> Response from Jyoti:
> 
>> The mpic_setup_error_int() leak is intentionally left to a separate 
>> patch
>> already under
> 
> If that's the case, you shouldn't have mentioned about this change in 
> the commit
> log of this patch.  The commit log needs to be updated accordingly if 
> that's
> what your intent is.

Agree,I'llfix it in v2.

>>  review:
>> "[PATCH] powerpc: Fix missing of_node_put() calls"
>> That patch converts the return NULL at line 1392 to goto 
>> err_of_node_put as
>> part of a
> 
> I could only find below:
> 
> https://lore.kernel.org/all/5cef10ab1610113fe162cec1dffd97f3@linux.ibm.com/
> 
> Sorry, but I don't think thats the right way to send a patch.  You seem 
> to have
> replied to the email which did not land into the mailing lists at all.

Yes, I made a mistake earlier by not keeping 
linuxppc-dev@lists.ozlabs.org
in the loop. I later replied to all with the list included, but I 
understand
that was not the right way to do it. I'll resend the patch as a fresh 
thread
in the proper format.

> Having
> said that, I think fixing this particular path in mpic_alloc() would 
> make more
> sense in the current patch itself.

sure we can do that too.

> Please look into fixing your mail client and send the patches/responses 
> in
> proper format.
> 

Got it.

Thanks,
Jyoti

> Thanks,
> Amit.
> 
>> broader of_node_put() fix series. This patch focuses only on the
>> irq_domain_create_linear()
>> failure path.
>> 
>> Thanks,
>> Jyoti



^ permalink raw reply	[flat|nested] 7+ messages in thread
* [PATCH] powerpc/mpic: Fix memory leak of mpic on error paths
@ 2026-09-24  6:30 Jyoti Gupta
  2026-09-24  9:28 ` Mukesh Kumar Chaurasiya
  2026-09-24  9:35 ` Amit Machhiwal
  0 siblings, 2 replies; 7+ messages in thread
From: Jyoti Gupta @ 2026-09-24  6:30 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: maddy, mpe, npiggin, chleroy, ritesh.list, sshegde, sourabhjain

mpic_alloc() allocates struct mpic (and optionally the protected
sources bitmap) but does not free them when mpic_setup_error_int() or
irq_domain_create_linear() fails, leaking the memory.

Initialise mpic to NULL and free the bitmap and the mpic in the common
error path before dropping the device node reference. The register
mappings are not released here.

Signed-off-by: Jyoti Gupta <jyoti@linux.ibm.com>
---
 arch/powerpc/sysdev/mpic.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 6e8fa94985f3..e777b33f170d 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1221,7 +1221,7 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 				const char *name)
 {
 	int i, psize, intvec_top;
-	struct mpic *mpic;
+	struct mpic *mpic = NULL;
 	u32 greg_feature;
 	const char *vers;
 	const u32 *psrc;
@@ -1488,10 +1488,6 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 						 intvec_top,
 						 &mpic_host_ops, mpic);
 
-	/*
-	 * FIXME: The code leaks the MPIC object and mappings here; this
-	 * is very unlikely to fail but it ought to be fixed anyways.
-	 */
 	if (mpic->irqhost == NULL)
 		goto err_of_node_put;
 
@@ -1527,6 +1523,9 @@ struct mpic * __init mpic_alloc(struct device_node *node,
 	return mpic;
 
 err_of_node_put:
+	if (mpic)
+		bitmap_free(mpic->protected);
+	kfree(mpic);
 	of_node_put(node);
 	return NULL;
 }
-- 
2.55.0



^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2026-09-30 16:41 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-09-30 16:41 [PATCH] powerpc/mpic: Fix memory leak of mpic on error paths Jyoti Gupta
  -- strict thread matches above, loose matches on Subject: below --
2026-09-24  6:30 Jyoti Gupta
2026-09-24  9:28 ` Mukesh Kumar Chaurasiya
2026-09-29  6:45   ` jyoti
2026-09-24  9:35 ` Amit Machhiwal
2026-09-29  6:36   ` jyoti
2026-09-29  7:32   ` Amit Machhiwal

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.