diff options
Diffstat (limited to 'drivers/firewire/core-device.c')
| -rw-r--r-- | drivers/firewire/core-device.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c index c0976f6268d329..e6cdb905eeaca7 100644 --- a/drivers/firewire/core-device.c +++ b/drivers/firewire/core-device.c @@ -322,7 +322,8 @@ static ssize_t show_immediate(struct device *dev, if (value < 0) return -ENOENT; - return sysfs_emit(buf, "0x%06x\n", value); + // Note that this function is also called by init_fw_attribute_group() with NULL pointer. + return buf ? sysfs_emit(buf, "0x%06x\n", value) : 0; } #define IMMEDIATE_ATTR(name, key) \ @@ -334,6 +335,8 @@ static ssize_t show_text_leaf(struct device *dev, struct config_rom_attribute *attr = container_of(dattr, struct config_rom_attribute, attr); const u32 *directories[] = {NULL, NULL}; + size_t bufsize; + char dummy_buf[2]; int i, ret = -ENOENT; down_read(&fw_device_rwsem); @@ -355,9 +358,16 @@ static ssize_t show_text_leaf(struct device *dev, } } + // Note that this function is also called by init_fw_attribute_group() with NULL pointer. + if (buf) { + bufsize = PAGE_SIZE - 1; + } else { + buf = dummy_buf; + bufsize = 1; + } + for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) { - int result = fw_csr_string(directories[i], attr->key, buf, - PAGE_SIZE - 1); + int result = fw_csr_string(directories[i], attr->key, buf, bufsize); // Detected. if (result >= 0) { ret = result; @@ -366,7 +376,7 @@ static ssize_t show_text_leaf(struct device *dev, // in the root directory follows to the directory entry for vendor ID // instead of the immediate value for vendor ID. result = fw_csr_string(directories[i], CSR_DIRECTORY | attr->key, buf, - PAGE_SIZE - 1); + bufsize); if (result >= 0) ret = result; } |