Messages in this thread Patch in this message | | | Date | Wed, 12 Mar 2003 17:47:15 +0100 | From | Christoph Hellwig <> | Subject | [PATCH] fix OOPS in i2c sysctl registration |
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I had to rewrite the code from scratch to understand what it does, but at least it doesn't OOPS anymore on boot..
--- 1.16/drivers/i2c/i2c-proc.c Thu Feb 20 15:02:00 2003 +++ edited/drivers/i2c/i2c-proc.c Wed Mar 12 15:37:16 2003 @@ -35,8 +35,6 @@ #include <linux/i2c-proc.h> #include <asm/uaccess.h> -static int i2c_create_name(char **name, const char *prefix, - struct i2c_adapter *adapter, int addr); static int i2c_parse_reals(int *nrels, void *buffer, int bufsize, long *results, int magnitude); static int i2c_write_reals(int nrels, void *buffer, size_t *bufsize, @@ -54,15 +52,6 @@ static struct i2c_client *i2c_clients[SENSORS_ENTRY_MAX]; -static ctl_table sysctl_table[] = { - {CTL_DEV, "dev", NULL, 0, 0555}, - {0}, - {DEV_SENSORS, "sensors", NULL, 0, 0555}, - {0}, - {0, NULL, NULL, 0, 0555}, - {0} -}; - static ctl_table i2c_proc_dev_sensors[] = { {SENSORS_CHIPS, "chips", NULL, 0, 0644, NULL, &i2c_proc_chips, &i2c_sysctl_chips}, @@ -87,36 +76,40 @@ (for a LM78 chip on the ISA bus at port 0x310), or lm75-i2c-3-4e (for a LM75 chip on the third i2c bus at address 0x4e). name is allocated first. */ -static int i2c_create_name(char **name, const char *prefix, - struct i2c_adapter *adapter, int addr) +static char *generate_name(struct i2c_client *client, const char *prefix) { - char name_buffer[50]; - int id, i, end; - if (i2c_is_isa_adapter(adapter)) + struct i2c_adapter *adapter = client->adapter; + int addr = client->addr; + char name_buffer[50], *name; + + if (i2c_is_isa_adapter(adapter)) { sprintf(name_buffer, "%s-isa-%04x", prefix, addr); - else if (!adapter->algo->smbus_xfer && !adapter->algo->master_xfer) { - /* dummy adapter, generate prefix */ + } else if (adapter->algo->smbus_xfer || adapter->algo->master_xfer) { + int id = i2c_adapter_id(adapter); + if (id < 0) + return ERR_PTR(-ENOENT); + sprintf(name_buffer, "%s-i2c-%d-%02x", prefix, id, addr); + } else { /* dummy adapter, generate prefix */ + int end, i; + sprintf(name_buffer, "%s-", prefix); end = strlen(name_buffer); - for(i = 0; i < 32; i++) { - if(adapter->algo->name[i] == ' ') + + for (i = 0; i < 32; i++) { + if (adapter->algo->name[i] == ' ') break; name_buffer[end++] = tolower(adapter->algo->name[i]); } + name_buffer[end] = 0; sprintf(name_buffer + end, "-%04x", addr); - } else { - if ((id = i2c_adapter_id(adapter)) < 0) - return -ENOENT; - sprintf(name_buffer, "%s-i2c-%d-%02x", prefix, id, addr); - } - *name = kmalloc(strlen(name_buffer) + 1, GFP_KERNEL); - if (!*name) { - printk (KERN_WARNING "i2c_create_name: not enough memory\n"); - return -ENOMEM; } - strcpy(*name, name_buffer); - return 0; + + name = kmalloc(strlen(name_buffer) + 1, GFP_KERNEL); + if (unlikely(!name)) + return ERR_PTR(-ENOMEM); + strcpy(name, name_buffer); + return name; } /* This rather complex function must be called when you want to add an entry @@ -127,93 +120,80 @@ If any driver wants subdirectories within the newly created directory, this function must be updated! */ int i2c_register_entry(struct i2c_client *client, const char *prefix, - ctl_table * ctl_template) + struct ctl_table *leaf) { - int i, res, len, id; - ctl_table *new_table, *client_tbl, *tbl; - char *name; - struct ctl_table_header *new_header; - - if ((res = i2c_create_name(&name, prefix, client->adapter, - client->addr))) return res; - - for (id = 0; id < SENSORS_ENTRY_MAX; id++) - if (!i2c_entries[id]) { - break; - } - if (id == SENSORS_ENTRY_MAX) { - kfree(name); - return -ENOMEM; - } - - id += 256; - - len = 0; - while (ctl_template[len].procname) - len++; - if (!(new_table = kmalloc(sizeof(sysctl_table) + sizeof(ctl_table) * (len + 1), - GFP_KERNEL))) { - kfree(name); - return -ENOMEM; - } - - memcpy(new_table, sysctl_table, sizeof(sysctl_table)); - tbl = new_table; /* sys/ */ - tbl = tbl->child = tbl + 2; /* dev/ */ - tbl = tbl->child = tbl + 2; /* sensors/ */ - client_tbl = tbl->child = tbl + 2; /* XX-chip-YY-ZZ/ */ - - client_tbl->procname = name; - client_tbl->ctl_name = id; - client_tbl->child = client_tbl + 2; - - /* Next the client sysctls. --km */ - tbl = client_tbl->child; - memcpy(tbl, ctl_template, sizeof(ctl_table) * (len+1)); - for (i = 0; i < len; i++) - tbl[i].extra2 = client; - - if (!(new_header = register_sysctl_table(new_table, 0))) { - printk(KERN_ERR "i2c-proc.o: error: sysctl interface not supported by kernel!\n"); - kfree(new_table); - kfree(name); - return -EPERM; - } - - i2c_entries[id - 256] = new_header; - - i2c_clients[id - 256] = client; - -#ifdef DEBUG - if (!new_header || !new_header->ctl_table || - !new_header->ctl_table->child || - !new_header->ctl_table->child->child || - !new_header->ctl_table->child->child->de ) { - printk - (KERN_ERR "i2c-proc.o: NULL pointer when trying to install fill_inode fix!\n"); - return id; - } -#endif /* DEBUG */ - client_tbl->de->owner = client->driver->owner; - return id; + struct { struct ctl_table root[2], dev[2], sensors[2]; } *tbl; + struct ctl_table_header *hdr; + struct ctl_table *tmp; + const char *name; + int id; + + name = generate_name(client, prefix); + if (IS_ERR(name)) + return PTR_ERR(name); + + for (id = 0; id < SENSORS_ENTRY_MAX; id++) { + if (!i2c_entries[id]) + goto free_slot; + } + + goto out_free_name; + + free_slot: + tbl = kmalloc(sizeof(*tbl), GFP_KERNEL); + if (unlikely(!tbl)) + goto out_free_name; + memset(tbl, 0, sizeof(*tbl)); + + for (tmp = leaf; tmp->ctl_name; tmp++) + tmp->extra2 = client; + + tbl->sensors->ctl_name = id+256; + tbl->sensors->procname = name; + tbl->sensors->mode = 0555; + tbl->sensors->child = leaf; + + tbl->dev->ctl_name = DEV_SENSORS; + tbl->dev->procname = "sensors"; + tbl->dev->mode = 0555; + tbl->dev->child = tbl->sensors; + + tbl->root->ctl_name = CTL_DEV; + tbl->root->procname = "dev"; + tbl->root->mode = 0555; + tbl->root->child = tbl->dev; + + hdr = register_sysctl_table(tbl->root, 0); + if (unlikely(!hdr)) + goto out_free_tbl; + + i2c_entries[id] = hdr; + i2c_clients[id] = client; + + return (id + 256); /* XXX(hch) why?? */ + + out_free_tbl: + kfree(tbl); + out_free_name: + kfree(name); + return -ENOMEM; } void i2c_deregister_entry(int id) { - ctl_table *table; - char *temp; + id -= 256; - id -= 256; if (i2c_entries[id]) { - table = i2c_entries[id]->ctl_table; - unregister_sysctl_table(i2c_entries[id]); - /* 2-step kfree needed to keep gcc happy about const points */ - (const char *) temp = table[4].procname; - kfree(temp); - kfree(table); - i2c_entries[id] = NULL; - i2c_clients[id] = NULL; + struct ctl_table_header *hdr = i2c_entries[id]; + struct ctl_table *tbl = hdr->ctl_table; + + unregister_sysctl_table(hdr); + kfree(tbl->child->child->procname); + kfree(tbl); /* actually the whole anonymous struct */ } + + i2c_entries[id] = NULL; + i2c_clients[id] = NULL; } static int i2c_proc_chips(ctl_table * ctl, int write, struct file *filp, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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