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Date: Wed, 31 Oct 2018 12:54:39 -0400
From: Sasha Levin <sashal@kernel.org>
To: Ioannis Valasakis <code@wizofe.uk>
Cc: outreachy-kernel@googlegroups.com, gregkh@linuxfoundation.org,
	alexander.levin@microsoft.com
Subject: Re: [Outreachy kernel] [PATCH v2] staging: gasket Create a memory
 allocation path
Message-ID: <20181031165439.GU194472@sasha-vm>
References: <20181031164753.GA14140@kvasir.local>
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On Wed, Oct 31, 2018 at 04:47:54PM +0000, Ioannis Valasakis wrote:
>Fix multiple error allocation path by using re-direction.
>
>Signed-off-by: Ioannis Valasakis <code@wizofe.uk>
>---
>Changes in v2:
>	- Specific tags for memory allocation
>	- Free the memory in the right way as for kfre
>
>drivers/staging/gasket/gasket_interrupt.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
>diff --git a/drivers/staging/gasket/gasket_interrupt.c b/drivers/staging/gasket/gasket_interrupt.c
>index cdfb72af1c52..23232ea8f4d9 100644
>--- a/drivers/staging/gasket/gasket_interrupt.c
>+++ b/drivers/staging/gasket/gasket_interrupt.c
>@@ -348,21 +348,21 @@ int gasket_interrupt_init(struct gasket_dev *gasket_dev, const char *name,
> 					       sizeof(struct msix_entry),
> 					       GFP_KERNEL);
> 	if (!interrupt_data->msix_entries) {
>-		goto err_alloc;
>+		goto err_free_msix;
> 	}
>
> 	interrupt_data->eventfd_ctxs = kcalloc(num_interrupts,
> 					       sizeof(struct eventfd_ctx *),
> 					       GFP_KERNEL);
> 	if (!interrupt_data->eventfd_ctxs) {
>-		goto err_alloc;
>+		goto err_free_eventfd;
> 	}
>
> 	interrupt_data->interrupt_counts = kcalloc(num_interrupts,
> 						   sizeof(ulong),
> 						   GFP_KERNEL);
> 	if (!interrupt_data->interrupt_counts) {
>-		goto err_alloc;
>+		goto err_free_data;
> 	}
>
> 	switch (interrupt_data->type) {
>@@ -397,10 +397,12 @@ int gasket_interrupt_init(struct gasket_dev *gasket_dev, const char *name,
>
> 	return 0;
>
>-err_alloc:
>-	kfree(interrupt_data);
>-	kfree(interrupt_data->msix_entries);
>+err_free_msix:
> 	kfree(interrupt_data->eventfd_ctxs);
>+err_free_eventfd:
>+	kfree(interrupt_data->msix_entries);
>+err_free_data:
>+	kfree(interrupt_data);
> 	return -ENOMEM;
> }

With this code, what will happen if, for example, the last
allocation (interrupt_data->interrupt_counts) fails?

--
Thanks,
Sasha