Instead of copying @buf into a new buffer and carefully managing its
newline/null-terminating status, we can just use sysfs_match_string()
as it uses sysfs_streq() internally which handles newline/null-term:
| /**
| * sysfs_streq - return true if strings are equal, modulo trailing newline
| * @s1: one string
| * @s2: another string
| *
| * This routine returns true iff two strings are equal, treating both
| * NUL and newline-then-NUL as equivalent string terminations. It's
| * geared for use with sysfs input strings, which generally terminate
| * with newlines but are compared against values without newlines.
| */
| bool sysfs_streq(const char *s1, const char *s2)
| ...
Then entirely drop the now unused fcoe_parse_mode, being careful to
change if condition from checking for FIP_CONN_TYPE_UNKNOWN to < 0 as
sysfs_match_string can return -EINVAL. Also check explicitly if
ctlr->mode is equal to FIP_CONN_TYPE_UNKNOWN -- this is probably
preferred to "<=" as the behavior is more obvious while maintaining
functionality.
To get the compiler not to complain, make fip_conn_type_names
const char * const. Perhaps, this should also be done for
fcf_state_names.
This also removes an instance of strncpy() which helps [1].
Link: https://github.com/KSPP/linux/issues/90 [1]
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
Changes in v2:
- update if-cond to check for unknown type (thanks Kees)
- Link to v1: https://lore.kernel.org/r/20231211-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-v1-1-73b942238396@google.com
---
Builds upon patch and feedback from [2]:
However, this is different enough to warrant its own patch and not be a
continuation.
[2]: https://lore.kernel.org/all/[email protected]/
---
drivers/scsi/fcoe/fcoe_sysfs.c | 26 ++++----------------------
1 file changed, 4 insertions(+), 22 deletions(-)
diff --git a/drivers/scsi/fcoe/fcoe_sysfs.c b/drivers/scsi/fcoe/fcoe_sysfs.c
index e17957f8085c..408a806bf4c2 100644
--- a/drivers/scsi/fcoe/fcoe_sysfs.c
+++ b/drivers/scsi/fcoe/fcoe_sysfs.c
@@ -10,6 +10,7 @@
#include <linux/kernel.h>
#include <linux/etherdevice.h>
#include <linux/ctype.h>
+#include <linux/string.h>
#include <scsi/fcoe_sysfs.h>
#include <scsi/libfcoe.h>
@@ -214,25 +215,13 @@ static const char *get_fcoe_##title##_name(enum table_type table_key) \
return table[table_key]; \
}
-static char *fip_conn_type_names[] = {
+static const char * const fip_conn_type_names[] = {
[ FIP_CONN_TYPE_UNKNOWN ] = "Unknown",
[ FIP_CONN_TYPE_FABRIC ] = "Fabric",
[ FIP_CONN_TYPE_VN2VN ] = "VN2VN",
};
fcoe_enum_name_search(ctlr_mode, fip_conn_type, fip_conn_type_names)
-static enum fip_conn_type fcoe_parse_mode(const char *buf)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(fip_conn_type_names); i++) {
- if (strcasecmp(buf, fip_conn_type_names[i]) == 0)
- return i;
- }
-
- return FIP_CONN_TYPE_UNKNOWN;
-}
-
static char *fcf_state_names[] = {
[ FCOE_FCF_STATE_UNKNOWN ] = "Unknown",
[ FCOE_FCF_STATE_DISCONNECTED ] = "Disconnected",
@@ -274,17 +263,10 @@ static ssize_t store_ctlr_mode(struct device *dev,
const char *buf, size_t count)
{
struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev);
- char mode[FCOE_MAX_MODENAME_LEN + 1];
if (count > FCOE_MAX_MODENAME_LEN)
return -EINVAL;
- strncpy(mode, buf, count);
-
- if (mode[count - 1] == '\n')
- mode[count - 1] = '\0';
- else
- mode[count] = '\0';
switch (ctlr->enabled) {
case FCOE_CTLR_ENABLED:
@@ -297,8 +279,8 @@ static ssize_t store_ctlr_mode(struct device *dev,
return -ENOTSUPP;
}
- ctlr->mode = fcoe_parse_mode(mode);
- if (ctlr->mode == FIP_CONN_TYPE_UNKNOWN) {
+ ctlr->mode = sysfs_match_string(fip_conn_type_names, buf);
+ if (ctlr->mode < 0 || ctlr->mode == FIP_CONN_TYPE_UNKNOWN) {
LIBFCOE_SYSFS_DBG(ctlr, "Unknown mode %s provided.\n",
buf);
return -EINVAL;
---
base-commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8
change-id: 20231024-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-0e1dffe82855
Best regards,
--
Justin Stitt <[email protected]>
On Tue, Dec 12, 2023 at 11:19:06PM +0000, Justin Stitt wrote:
> Instead of copying @buf into a new buffer and carefully managing its
> newline/null-terminating status, we can just use sysfs_match_string()
> as it uses sysfs_streq() internally which handles newline/null-term:
>
> | /**
> | * sysfs_streq - return true if strings are equal, modulo trailing newline
> | * @s1: one string
> | * @s2: another string
> | *
> | * This routine returns true iff two strings are equal, treating both
> | * NUL and newline-then-NUL as equivalent string terminations. It's
> | * geared for use with sysfs input strings, which generally terminate
> | * with newlines but are compared against values without newlines.
> | */
> | bool sysfs_streq(const char *s1, const char *s2)
> | ...
>
> Then entirely drop the now unused fcoe_parse_mode, being careful to
> change if condition from checking for FIP_CONN_TYPE_UNKNOWN to < 0 as
> sysfs_match_string can return -EINVAL. Also check explicitly if
> ctlr->mode is equal to FIP_CONN_TYPE_UNKNOWN -- this is probably
> preferred to "<=" as the behavior is more obvious while maintaining
> functionality.
>
> To get the compiler not to complain, make fip_conn_type_names
> const char * const. Perhaps, this should also be done for
> fcf_state_names.
>
> This also removes an instance of strncpy() which helps [1].
>
> Link: https://github.com/KSPP/linux/issues/90 [1]
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
Looks great; thanks!
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
On 12/13/23 00:19, Justin Stitt wrote:
> Instead of copying @buf into a new buffer and carefully managing its
> newline/null-terminating status, we can just use sysfs_match_string()
> as it uses sysfs_streq() internally which handles newline/null-term:
>
> | /**
> | * sysfs_streq - return true if strings are equal, modulo trailing newline
> | * @s1: one string
> | * @s2: another string
> | *
> | * This routine returns true iff two strings are equal, treating both
> | * NUL and newline-then-NUL as equivalent string terminations. It's
> | * geared for use with sysfs input strings, which generally terminate
> | * with newlines but are compared against values without newlines.
> | */
> | bool sysfs_streq(const char *s1, const char *s2)
> | ...
>
> Then entirely drop the now unused fcoe_parse_mode, being careful to
> change if condition from checking for FIP_CONN_TYPE_UNKNOWN to < 0 as
> sysfs_match_string can return -EINVAL. Also check explicitly if
> ctlr->mode is equal to FIP_CONN_TYPE_UNKNOWN -- this is probably
> preferred to "<=" as the behavior is more obvious while maintaining
> functionality.
>
> To get the compiler not to complain, make fip_conn_type_names
> const char * const. Perhaps, this should also be done for
> fcf_state_names.
>
> This also removes an instance of strncpy() which helps [1].
>
> Link: https://github.com/KSPP/linux/issues/90 [1]
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
> ---
> Changes in v2:
> - update if-cond to check for unknown type (thanks Kees)
> - Link to v1: https://lore.kernel.org/r/20231211-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-v1-1-73b942238396@google.com
> ---
> Builds upon patch and feedback from [2]:
>
> However, this is different enough to warrant its own patch and not be a
> continuation.
>
> [2]: https://lore.kernel.org/all/[email protected]/
> ---
> drivers/scsi/fcoe/fcoe_sysfs.c | 26 ++++----------------------
> 1 file changed, 4 insertions(+), 22 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Ivo Totev, Andrew McDonald,
Werner Knoblich
Justin,
> Instead of copying @buf into a new buffer and carefully managing its
> newline/null-terminating status, we can just use sysfs_match_string()
> as it uses sysfs_streq() internally which handles newline/null-term:
Applied to 6.8/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
On Tue, 12 Dec 2023 23:19:06 +0000, Justin Stitt wrote:
> Instead of copying @buf into a new buffer and carefully managing its
> newline/null-terminating status, we can just use sysfs_match_string()
> as it uses sysfs_streq() internally which handles newline/null-term:
>
> | /**
> | * sysfs_streq - return true if strings are equal, modulo trailing newline
> | * @s1: one string
> | * @s2: another string
> | *
> | * This routine returns true iff two strings are equal, treating both
> | * NUL and newline-then-NUL as equivalent string terminations. It's
> | * geared for use with sysfs input strings, which generally terminate
> | * with newlines but are compared against values without newlines.
> | */
> | bool sysfs_streq(const char *s1, const char *s2)
> | ...
>
> [...]
Applied to 6.8/scsi-queue, thanks!
[1/1] scsi: fcoe: use sysfs_match_string over fcoe_parse_mode
https://git.kernel.org/mkp/scsi/c/edc22a7c8688
--
Martin K. Petersen Oracle Linux Engineering