Re: [dpdk-dev] [PATCH v7 03/12] eal: Fix memory leaks and needless increment of pci_map_addr

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Jun 30, 2015 at 05:24:19PM +0900, Tetsuya Mukawa wrote:
> From: "Tetsuya.Mukawa" <mukawa@igel.co.jp>
> 
> This patch fixes following memory leaks.
> - When open() is failed, uio_res and fds won't be freed in
>   pci_uio_map_resource().
> - When pci_map_resource() is failed but path is allocated correctly,
>   path and fds won't be freed in pci_uio_map_recource().
>   Also, some mapped resources should be freed.
> - When pci_uio_unmap() is called, path should be freed.
> 
> Also, fixes below.
> - When pci_map_resource() is failed, mapaddr will be MAP_FAILED.
>   In this case, pci_map_addr should not be incremented in
>   pci_uio_map_resource().
> - To shrink code, move close().
> - Remove fail variable.
> 
> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>

Couple of minor comments inline below.

/Bruce

> ---
>  lib/librte_eal/bsdapp/eal/eal_pci.c       | 14 ++++++--
>  lib/librte_eal/linuxapp/eal/eal_pci_uio.c | 56 ++++++++++++++++++++-----------
>  2 files changed, 48 insertions(+), 22 deletions(-)
> 
> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
> index 8e24fd1..b071f07 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> @@ -235,7 +235,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	if ((uio_res = rte_zmalloc("UIO_RES", sizeof (*uio_res), 0)) == NULL) {
>  		RTE_LOG(ERR, EAL,
>  			"%s(): cannot store uio mmap details\n", __func__);
> -		return -1;
> +		goto close_fd;
>  	}
>  
>  	snprintf(uio_res->path, sizeof(uio_res->path), "%s", devname);
> @@ -262,8 +262,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  		    (mapaddr = pci_map_resource(NULL, devname, (off_t)offset,
>  						(size_t)maps[j].size)
>  		    ) == NULL) {
> -			rte_free(uio_res);
> -			return -1;
> +			goto free_uio_res;
>  		}
>  
>  		maps[j].addr = mapaddr;
> @@ -274,6 +273,15 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	TAILQ_INSERT_TAIL(uio_res_list, uio_res, next);
>  
>  	return 0;
> +
> +free_uio_res:
> +	rte_free(uio_res);
If you initialize uio_res to NULL when it is defined, you can get rid of the
distinction between "free_uio_res" and "close_fd" labels. 

Similarly, if you check for a valid dev->intr_handle.fd value before close, you can have a 
generic "error" leg, and replace all return -1's with goto error. While not as
useful as merging the labels, it might be something to consider.

> +close_fd:
> +	close(dev->intr_handle.fd);
> +	dev->intr_handle.fd = -1;
> +	dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +
> +	return -1;
>  }
>  
>  /* Scan one pci sysfs entry, and fill the devices list from it. */
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
> index 34316b6..c3b259b 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
> @@ -308,7 +308,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	if (dev->intr_handle.uio_cfg_fd < 0) {
>  		RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
>  			cfgname, strerror(errno));
> -		return -1;
> +		goto close_fd;
>  	}
>  
>  	if (dev->kdrv == RTE_KDRV_IGB_UIO)
> @@ -319,7 +319,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  		/* set bus master that is not done by uio_pci_generic */
>  		if (pci_uio_set_bus_master(dev->intr_handle.uio_cfg_fd)) {
>  			RTE_LOG(ERR, EAL, "Cannot set up bus mastering!\n");
> -			return -1;
> +			goto close_fd;
>  		}
>  	}
>  
> @@ -328,7 +328,7 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	if (uio_res == NULL) {
>  		RTE_LOG(ERR, EAL,
>  			"%s(): cannot store uio mmap details\n", __func__);
> -		return -1;
> +		goto close_fd;
>  	}
>  
>  	snprintf(uio_res->path, sizeof(uio_res->path), "%s", devname);
> @@ -338,7 +338,6 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	maps = uio_res->maps;
>  	for (i = 0, map_idx = 0; i != PCI_MAX_RESOURCE; i++) {
>  		int fd;
> -		int fail = 0;
>  
>  		/* skip empty BAR */
>  		phaddr = dev->mem_resource[i].phys_addr;
> @@ -352,6 +351,11 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  				loc->domain, loc->bus, loc->devid, loc->function,
>  				i);
>  
> +		/* allocate memory to keep path */
> +		maps[map_idx].path = rte_malloc(NULL, strlen(devname) + 1, 0);
> +		if (maps[map_idx].path == NULL)
> +			goto free_uio_res;
> +
>  		/*
>  		 * open resource file, to mmap it
>  		 */
> @@ -359,7 +363,8 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  		if (fd < 0) {
>  			RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
>  					devname, strerror(errno));
> -			return -1;
> +			rte_free(maps[map_idx].path);
> +			goto free_uio_res;
>  		}
>  
>  		/* try mapping somewhere close to the end of hugepages */
> @@ -368,23 +373,15 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  
>  		mapaddr = pci_map_resource(pci_map_addr, fd, 0,
>  				(size_t)dev->mem_resource[i].len, 0);
> -		if (mapaddr == MAP_FAILED)
> -			fail = 1;
> +		close(fd);
> +		if (mapaddr == MAP_FAILED) {
> +			rte_free(maps[map_idx].path);
> +			goto free_uio_res;
> +		}
>  
>  		pci_map_addr = RTE_PTR_ADD(mapaddr,
>  				(size_t)dev->mem_resource[i].len);
>  
> -		maps[map_idx].path = rte_malloc(NULL, strlen(devname) + 1, 0);
> -		if (maps[map_idx].path == NULL)
> -			fail = 1;
> -
> -		if (fail) {
> -			rte_free(uio_res);
> -			close(fd);
> -			return -1;
> -		}
> -		close(fd);
> -
>  		maps[map_idx].phaddr = dev->mem_resource[i].phys_addr;
>  		maps[map_idx].size = dev->mem_resource[i].len;
>  		maps[map_idx].addr = mapaddr;
> @@ -399,6 +396,25 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  	TAILQ_INSERT_TAIL(uio_res_list, uio_res, next);
>  
>  	return 0;
> +
> +free_uio_res:
> +	for (i = 0; i < map_idx; i++) {

If you move the initialization of map_idx = 0 from the "for" loop to the definition
at the start of the function, you may again be able to merge these two labels
into one.

> +		pci_unmap_resource(uio_res->maps[i].addr,
> +				(size_t)uio_res->maps[i].size);
> +		rte_free(maps[i].path);
> +	}
> +	rte_free(uio_res);
> +close_fd:
> +	if (dev->intr_handle.uio_cfg_fd >= 0) {
> +		close(dev->intr_handle.uio_cfg_fd);
> +		dev->intr_handle.uio_cfg_fd = -1;
> +	}
> +
> +	close(dev->intr_handle.fd);
> +	dev->intr_handle.fd = -1;
> +	dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +
> +	return -1;
>  }
>  
>  #ifdef RTE_LIBRTE_EAL_HOTPLUG
> @@ -410,9 +426,11 @@ pci_uio_unmap(struct mapped_pci_resource *uio_res)
>  	if (uio_res == NULL)
>  		return;
>  
> -	for (i = 0; i != uio_res->nb_maps; i++)
> +	for (i = 0; i != uio_res->nb_maps; i++) {
>  		pci_unmap_resource(uio_res->maps[i].addr,
>  				(size_t)uio_res->maps[i].size);
> +		rte_free(uio_res->maps[i].path);
> +	}
>  }
>  
>  static struct mapped_pci_resource *
> -- 
> 2.1.4
>