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authorJan Beulich <JBeulich@suse.com>2012-11-02 14:36:38 +0000
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-11-02 11:04:02 -0400
commit5b71fbdc64225b7a86944f4f0de80e59071187c7 (patch)
tree4a3ea77d3a531194d55156252aa12e430132be0a /drivers/xen/xen-pciback
parent9d02b43dee0d7fb18dfb13a00915550b1a3daa9f (diff)
xen-pciback: simplify and tighten parsing of device IDs
Now that at least one of the conformance problems of the kernel's sscanf() was addressed (commit da99075c1d368315e1508b6143226c0d27b621e0), we can improve the parsing done in xen-pciback both in terms of code readability and correctness (in particular properly rejecting input strings not well formed). Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/xen-pciback')
-rw-r--r--drivers/xen/xen-pciback/pci_stub.c83
1 files changed, 39 insertions, 44 deletions
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 961d664e2d2f..1a92739f4318 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -897,42 +897,35 @@ static struct pci_driver xen_pcibk_pci_driver = {
static inline int str_to_slot(const char *buf, int *domain, int *bus,
int *slot, int *func)
{
- int err;
- char wc = '*';
+ int parsed = 0;
- err = sscanf(buf, " %x:%x:%x.%x", domain, bus, slot, func);
- switch (err) {
+ switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func,
+ &parsed)) {
case 3:
*func = -1;
- err = sscanf(buf, " %x:%x:%x.%c", domain, bus, slot, &wc);
+ sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed);
break;
case 2:
*slot = *func = -1;
- err = sscanf(buf, " %x:%x:*.%c", domain, bus, &wc);
- if (err >= 2)
- ++err;
+ sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed);
break;
}
- if (err == 4 && wc == '*')
+ if (parsed && !buf[parsed])
return 0;
- else if (err < 0)
- return -EINVAL;
/* try again without domain */
*domain = 0;
- wc = '*';
- err = sscanf(buf, " %x:%x.%x", bus, slot, func);
- switch (err) {
+ switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) {
case 2:
*func = -1;
- err = sscanf(buf, " %x:%x.%c", bus, slot, &wc);
+ sscanf(buf, " %x:%x.* %n", bus, slot, &parsed);
break;
case 1:
*slot = *func = -1;
- err = sscanf(buf, " %x:*.%c", bus, &wc) + 1;
+ sscanf(buf, " %x:*.* %n", bus, &parsed);
break;
}
- if (err == 3 && wc == '*')
+ if (parsed && !buf[parsed])
return 0;
return -EINVAL;
@@ -941,13 +934,20 @@ static inline int str_to_slot(const char *buf, int *domain, int *bus,
static inline int str_to_quirk(const char *buf, int *domain, int *bus, int
*slot, int *func, int *reg, int *size, int *mask)
{
- int err;
+ int parsed = 0;
+
+ sscanf(buf, " %4x:%2x:%2x.%d-%8x:%1x:%8x %n", domain, bus, slot, func,
+ reg, size, mask, &parsed);
+ if (parsed && !buf[parsed])
+ return 0;
- err =
- sscanf(buf, " %04x:%02x:%02x.%d-%08x:%1x:%08x", domain, bus, slot,
- func, reg, size, mask);
- if (err == 7)
+ /* try again without domain */
+ *domain = 0;
+ sscanf(buf, " %2x:%2x.%d-%8x:%1x:%8x %n", bus, slot, func, reg, size,
+ mask, &parsed);
+ if (parsed && !buf[parsed])
return 0;
+
return -EINVAL;
}
@@ -1339,8 +1339,6 @@ static int __init pcistub_init(void)
if (pci_devs_to_hide && *pci_devs_to_hide) {
do {
- char wc = '*';
-
parsed = 0;
err = sscanf(pci_devs_to_hide + pos,
@@ -1349,51 +1347,48 @@ static int __init pcistub_init(void)
switch (err) {
case 3:
func = -1;
- err = sscanf(pci_devs_to_hide + pos,
- " (%x:%x:%x.%c) %n",
- &domain, &bus, &slot, &wc,
- &parsed);
+ sscanf(pci_devs_to_hide + pos,
+ " (%x:%x:%x.*) %n",
+ &domain, &bus, &slot, &parsed);
break;
case 2:
slot = func = -1;
- err = sscanf(pci_devs_to_hide + pos,
- " (%x:%x:*.%c) %n",
- &domain, &bus, &wc, &parsed) + 1;
+ sscanf(pci_devs_to_hide + pos,
+ " (%x:%x:*.*) %n",
+ &domain, &bus, &parsed);
break;
}
- if (err != 4 || wc != '*') {
+ if (!parsed) {
domain = 0;
- wc = '*';
err = sscanf(pci_devs_to_hide + pos,
" (%x:%x.%x) %n",
&bus, &slot, &func, &parsed);
switch (err) {
case 2:
func = -1;
- err = sscanf(pci_devs_to_hide + pos,
- " (%x:%x.%c) %n",
- &bus, &slot, &wc,
- &parsed);
+ sscanf(pci_devs_to_hide + pos,
+ " (%x:%x.*) %n",
+ &bus, &slot, &parsed);
break;
case 1:
slot = func = -1;
- err = sscanf(pci_devs_to_hide + pos,
- " (%x:*.%c) %n",
- &bus, &wc, &parsed) + 1;
+ sscanf(pci_devs_to_hide + pos,
+ " (%x:*.*) %n",
+ &bus, &parsed);
break;
}
- if (err != 3 || wc != '*')
- goto parse_error;
}
+ if (parsed <= 0)
+ goto parse_error;
+
err = pcistub_device_id_add(domain, bus, slot, func);
if (err)
goto out;
- /* if parsed<=0, we've reached the end of the string */
pos += parsed;
- } while (parsed > 0 && pci_devs_to_hide[pos]);
+ } while (pci_devs_to_hide[pos]);
}
/* If we're the first PCI Device Driver to register, we're the