From 6613c5e8603bc41741487828f48c6a4d701f7814 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 14 Dec 2009 18:00:11 -0800 Subject: [PATCH] uml: convert to seq_file/proc_fops Convert code away from ->read_proc/->write_proc interfaces. Switch to proc_create()/proc_create_data() which make addition of proc entries reliable wrt NULL ->proc_fops, NULL ->data and so on. Problem with ->read_proc et al is described here commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in /proc entries" Signed-off-by: Alexey Dobriyan Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/mconsole_kern.c | 14 ++++++++------ arch/um/drivers/ubd_kern.c | 36 +++++++++++++++++----------------- arch/um/kernel/exitcode.c | 43 ++++++++++++++++++++++------------------- arch/um/kernel/process.c | 31 +++++++++++++++++++---------- 4 files changed, 70 insertions(+), 54 deletions(-) diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index e14629c..f0fa47f 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -833,8 +833,8 @@ static int __init mconsole_init(void) __initcall(mconsole_init); -static int write_proc_mconsole(struct file *file, const char __user *buffer, - unsigned long count, void *data) +static ssize_t mconsole_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) { char *buf; @@ -855,6 +855,11 @@ static int write_proc_mconsole(struct file *file, const char __user *buffer, return count; } +static const struct file_operations mconsole_proc_fops = { + .owner = THIS_MODULE, + .write = mconsole_proc_write, +}; + static int create_proc_mconsole(void) { struct proc_dir_entry *ent; @@ -862,15 +867,12 @@ static int create_proc_mconsole(void) if (notify_socket == NULL) return 0; - ent = create_proc_entry("mconsole", S_IFREG | 0200, NULL); + ent = proc_create("mconsole", 0200, NULL, &mconsole_proc_fops); if (ent == NULL) { printk(KERN_INFO "create_proc_mconsole : create_proc_entry " "failed\n"); return 0; } - - ent->read_proc = NULL; - ent->write_proc = write_proc_mconsole; return 0; } diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 635d16d..5ff5546 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -27,6 +27,7 @@ #include "linux/init.h" #include "linux/cdrom.h" #include "linux/proc_fs.h" +#include "linux/seq_file.h" #include "linux/ctype.h" #include "linux/capability.h" #include "linux/mm.h" @@ -200,23 +201,25 @@ static void make_proc_ide(void) proc_ide = proc_mkdir("ide0", proc_ide_root); } -static int proc_ide_read_media(char *page, char **start, off_t off, int count, - int *eof, void *data) +static int fake_ide_media_proc_show(struct seq_file *m, void *v) { - int len; - - strcpy(page, "disk\n"); - len = strlen("disk\n"); - len -= off; - if (len < count){ - *eof = 1; - if (len <= 0) return 0; - } - else len = count; - *start = page + off; - return len; + seq_puts(m, "disk\n"); + return 0; +} + +static int fake_ide_media_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, fake_ide_media_proc_show, NULL); } +static const struct file_operations fake_ide_media_proc_fops = { + .owner = THIS_MODULE, + .open = fake_ide_media_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void make_ide_entries(const char *dev_name) { struct proc_dir_entry *dir, *ent; @@ -227,11 +230,8 @@ static void make_ide_entries(const char *dev_name) dir = proc_mkdir(dev_name, proc_ide); if(!dir) return; - ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); + ent = proc_create("media", S_IRUGO, dir, &fake_ide_media_proc_fops); if(!ent) return; - ent->data = NULL; - ent->read_proc = proc_ide_read_media; - ent->write_proc = NULL; snprintf(name, sizeof(name), "ide0/%s", dev_name); proc_symlink(dev_name, proc_ide_root, name); } diff --git a/arch/um/kernel/exitcode.c b/arch/um/kernel/exitcode.c index 6540d2c..829df49 100644 --- a/arch/um/kernel/exitcode.c +++ b/arch/um/kernel/exitcode.c @@ -6,7 +6,9 @@ #include #include #include +#include #include +#include #include #include @@ -16,30 +18,26 @@ */ int uml_exitcode = 0; -static int read_proc_exitcode(char *page, char **start, off_t off, - int count, int *eof, void *data) +static int exitcode_proc_show(struct seq_file *m, void *v) { - int len, val; + int val; /* * Save uml_exitcode in a local so that we don't need to guarantee * that sprintf accesses it atomically. */ val = uml_exitcode; - len = sprintf(page, "%d\n", val); - len -= off; - if (len <= off+count) - *eof = 1; - *start = page + off; - if (len > count) - len = count; - if (len < 0) - len = 0; - return len; + seq_printf(m, "%d\n", val); + return 0; +} + +static int exitcode_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, exitcode_proc_show, NULL); } -static int write_proc_exitcode(struct file *file, const char __user *buffer, - unsigned long count, void *data) +static ssize_t exitcode_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) { char *end, buf[sizeof("nnnnn\0")]; int tmp; @@ -55,20 +53,25 @@ static int write_proc_exitcode(struct file *file, const char __user *buffer, return count; } +static const struct file_operations exitcode_proc_fops = { + .owner = THIS_MODULE, + .open = exitcode_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = exitcode_proc_write, +}; + static int make_proc_exitcode(void) { struct proc_dir_entry *ent; - ent = create_proc_entry("exitcode", 0600, NULL); + ent = proc_create("exitcode", 0600, NULL, &exitcode_proc_fops); if (ent == NULL) { printk(KERN_WARNING "make_proc_exitcode : Failed to register " "/proc/exitcode\n"); return 0; } - - ent->read_proc = read_proc_exitcode; - ent->write_proc = write_proc_exitcode; - return 0; } diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 4a28a15..2f910a1 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -9,11 +9,13 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include #include @@ -336,16 +338,19 @@ int get_using_sysemu(void) return atomic_read(&using_sysemu); } -static int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data) +static int sysemu_proc_show(struct seq_file *m, void *v) { - if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) - /* No overflow */ - *eof = 1; + seq_printf(m, "%d\n", get_using_sysemu()); + return 0; +} - return strlen(buf); +static int sysemu_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, sysemu_proc_show, NULL); } -static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned long count,void *data) +static ssize_t sysemu_proc_write(struct file *file, const char __user *buf, + size_t count, loff_t *pos) { char tmp[2]; @@ -358,13 +363,22 @@ static int proc_write_sysemu(struct file *file,const char __user *buf, unsigned return count; } +static const struct file_operations sysemu_proc_fops = { + .owner = THIS_MODULE, + .open = sysemu_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = sysemu_proc_write, +}; + int __init make_proc_sysemu(void) { struct proc_dir_entry *ent; if (!sysemu_supported) return 0; - ent = create_proc_entry("sysemu", 0600, NULL); + ent = proc_create("sysemu", 0600, NULL, &sysemu_proc_fops); if (ent == NULL) { @@ -372,9 +386,6 @@ int __init make_proc_sysemu(void) return 0; } - ent->read_proc = proc_read_sysemu; - ent->write_proc = proc_write_sysemu; - return 0; } -- 2.7.4