[dpdk-dev] [PATCH v1 0/2] pci: a comment and a minor fix

[dpdk-dev] [PATCH v1 0/2] pci: a comment and a minor fix

[Gaetan Rivet]

Add a clarifying comment and fix the PCI addr parser behavior for
some edge-case.

Gaetan Rivet (2):
  pci: fix allowing underflow when parsing PCI id
  pci: explain how empty strings are rejected in DBDF

 lib/librte_pci/rte_pci.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

-- 
2.26.2

[dpdk-dev] [PATCH v1 1/2] pci: fix allowing underflow when parsing PCI id

[Gaetan Rivet]

The function strtoul will not return ERANGE if the input is negative, as
one might expect.

   0000:-FFFFFFFFFFFFFFFB:00.0

is not a better way to write 0000:05:00.0.
To simplify checking for '-', forbid using spaces before the field value.

   0000: 00:   2c.0

Should not be accepted.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Gaetan Rivet <grive@u256.net>
---
 lib/librte_pci/rte_pci.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
index d1ab6b414..e4ecdc32f 100644
--- a/lib/librte_pci/rte_pci.c
+++ b/lib/librte_pci/rte_pci.c
@@ -35,6 +35,12 @@ get_u8_pciaddr_field(const char *in, void *_u8, char dlm)
 	if (*in == '\0')
 		return NULL;
 
+	/* PCI field starting with spaces is forbidden.
+	 * Negative wrap-around is not reported as an error by strtoul.
+	 */
+	if (*in == ' ' || *in == '-')
+		return NULL;
+
 	errno = 0;
 	val = strtoul(in, &end, 16);
 	if (errno != 0 || end[0] != dlm || val > UINT8_MAX) {
@@ -70,6 +76,12 @@ pci_dbdf_parse(const char *input, struct rte_pci_addr *dev_addr)
 	unsigned long val;
 	char *end;
 
+	/* PCI id starting with spaces is forbidden.
+	 * Negative wrap-around is not reported as an error by strtoul.
+	 */
+	if (*in == ' ' || *in == '-')
+		return EINVAL;
+
 	errno = 0;
 	val = strtoul(in, &end, 16);
 	if (errno != 0 || end[0] != ':' || val > UINT16_MAX)
-- 
2.26.2

[dpdk-dev] [PATCH v1 2/2] pci: explain how empty strings are rejected in DBDF

[Gaetan Rivet]

Empty strings are forbidden as input to rte_pci_addr_parse().
It is explicitly enforced in BDF parsing as parsing the bus
field will immediately fail. The related check is commented.

It is implicitly enforced in DBDF parsing, as the domain would be
parsed to 0 without error, but the check `end[0] != ':'` afterward
will return -EINVAL.

Enforcing consistency between parsers by reading the code is not helped
by this property being implicit. Add a comment to explain.

Signed-off-by: Gaetan Rivet <grive@u256.net>
---
 lib/librte_pci/rte_pci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
index e4ecdc32f..60e6fbae7 100644
--- a/lib/librte_pci/rte_pci.c
+++ b/lib/librte_pci/rte_pci.c
@@ -84,6 +84,10 @@ pci_dbdf_parse(const char *input, struct rte_pci_addr *dev_addr)
 
 	errno = 0;
 	val = strtoul(in, &end, 16);
+	/* Empty string is not an error for strtoul, but the check
+	 *   end[0] != ':'
+	 * will detect the issue.
+	 */
 	if (errno != 0 || end[0] != ':' || val > UINT16_MAX)
 		return -EINVAL;
 	dev_addr->domain = (uint16_t)val;
-- 
2.26.2

Re: [dpdk-dev] [PATCH v1 1/2] pci: fix allowing underflow when parsing PCI id

[Stojaczyk, Dariusz]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Gaetan Rivet
> Sent: Wednesday, May 13, 2020 12:48 PM
> To: dev@dpdk.org
> Cc: stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v1 1/2] pci: fix allowing underflow when parsing PCI
> id
> 
> The function strtoul will not return ERANGE if the input is negative, as
> one might expect.
> 
>    0000:-FFFFFFFFFFFFFFFB:00.0
> 
> is not a better way to write 0000:05:00.0.
> To simplify checking for '-', forbid using spaces before the field value.
> 
>    0000: 00:   2c.0
> 
> Should not be accepted.
> 
> Fixes: af75078fece3 ("first public release")
> Cc: stable@dpdk.org
> Signed-off-by: Gaetan Rivet <grive@u256.net>
> ---

Acked-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

Re: [dpdk-dev] [PATCH v1 2/2] pci: explain how empty strings are rejected in DBDF

[Stojaczyk, Dariusz]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Gaetan Rivet
> Sent: Wednesday, May 13, 2020 12:48 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v1 2/2] pci: explain how empty strings are rejected
> in DBDF
> 
> Empty strings are forbidden as input to rte_pci_addr_parse().
> It is explicitly enforced in BDF parsing as parsing the bus
> field will immediately fail. The related check is commented.
> 
> It is implicitly enforced in DBDF parsing, as the domain would be
> parsed to 0 without error, but the check `end[0] != ':'` afterward
> will return -EINVAL.
> 
> Enforcing consistency between parsers by reading the code is not helped
> by this property being implicit. Add a comment to explain.
> 
> Signed-off-by: Gaetan Rivet <grive@u256.net>
> ---

Acked-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

Re: [dpdk-dev] [PATCH v1 1/2] pci: fix allowing underflow when parsing PCI id

[David Marchand]

On Wed, May 13, 2020 at 12:48 PM Gaetan Rivet <grive@u256.net> wrote:
>
> The function strtoul will not return ERANGE if the input is negative, as
> one might expect.
>
>    0000:-FFFFFFFFFFFFFFFB:00.0
>
> is not a better way to write 0000:05:00.0.
> To simplify checking for '-', forbid using spaces before the field value.
>
>    0000: 00:   2c.0
>
> Should not be accepted.
>
> Fixes: af75078fece3 ("first public release")
> Cc: stable@dpdk.org

Not sure about backporting this one, will let stable maintainers
reconsider this.


> Signed-off-by: Gaetan Rivet <grive@u256.net>
Acked-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

> ---
>  lib/librte_pci/rte_pci.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
> index d1ab6b414..e4ecdc32f 100644
> --- a/lib/librte_pci/rte_pci.c
> +++ b/lib/librte_pci/rte_pci.c
> @@ -35,6 +35,12 @@ get_u8_pciaddr_field(const char *in, void *_u8, char dlm)
>         if (*in == '\0')
>                 return NULL;
>
> +       /* PCI field starting with spaces is forbidden.
> +        * Negative wrap-around is not reported as an error by strtoul.
> +        */
> +       if (*in == ' ' || *in == '-')
> +               return NULL;
> +
>         errno = 0;
>         val = strtoul(in, &end, 16);
>         if (errno != 0 || end[0] != dlm || val > UINT8_MAX) {
> @@ -70,6 +76,12 @@ pci_dbdf_parse(const char *input, struct rte_pci_addr *dev_addr)
>         unsigned long val;
>         char *end;
>
> +       /* PCI id starting with spaces is forbidden.
> +        * Negative wrap-around is not reported as an error by strtoul.
> +        */
> +       if (*in == ' ' || *in == '-')
> +               return EINVAL;

Should be -EINVAL, fixed.

> +
>         errno = 0;
>         val = strtoul(in, &end, 16);
>         if (errno != 0 || end[0] != ':' || val > UINT16_MAX)
> --
> 2.26.2
>

Applied, thanks.


-- 
David Marchand

Re: [dpdk-dev] [PATCH v1 2/2] pci: explain how empty strings are rejected in DBDF

[David Marchand]

On Wed, May 13, 2020 at 12:48 PM Gaetan Rivet <grive@u256.net> wrote:
>
> Empty strings are forbidden as input to rte_pci_addr_parse().
> It is explicitly enforced in BDF parsing as parsing the bus
> field will immediately fail. The related check is commented.
>
> It is implicitly enforced in DBDF parsing, as the domain would be
> parsed to 0 without error, but the check `end[0] != ':'` afterward
> will return -EINVAL.
>
> Enforcing consistency between parsers by reading the code is not helped
> by this property being implicit. Add a comment to explain.
>
> Signed-off-by: Gaetan Rivet <grive@u256.net>
Acked-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>


Applied, thanks.

-- 
David Marchand