[PATCH 19/23] proc: Modify proc_pident_lookup to be completelytable driven.

From: Eric W. Biederman
Date: Thu Feb 23 2006 - 11:26:11 EST

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Currently proc_pident_lookup gets the names and types from a table
and then has a huge switch statement to get the inode and file
operations it needs. That is silly and is becoming increasingly hard
to maintain so I just put all of the information in the table.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>

---

fs/proc/base.c | 332 +++++++++++++++--------------------------------
include/linux/proc_fs.h | 10 +
2 files changed, 109 insertions(+), 233 deletions(-)

aa1e6b9f7d2bf0d4a39fcb1ebd3c539e1287ea45
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 71edbad..b27175a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -189,9 +189,37 @@ struct pid_entry {
int len;
char *name;
mode_t mode;
-};
+ struct inode_operations *iop;
+ struct file_operations *fop;
+ union proc_op op;
+};
+
+#define NOD(TYPE, NAME, MODE, IOP, FOP, OP) { \
+ .type = (TYPE), \
+ .len = sizeof(NAME) - 1, \
+ .name = (NAME), \
+ .mode = MODE, \
+ .iop = IOP, \
+ .fop = FOP, \
+ .op = OP, \
+}
+
+#define DIR(TYPE, NAME, MODE, OTYPE) \
+ NOD(TYPE, NAME, (S_IFDIR|(MODE)), \
+ &proc_##OTYPE##_inode_operations, &proc_##OTYPE##_operations, \
+ {} )
+#define LNK(TYPE, NAME, OTYPE) \
+ NOD(TYPE, NAME, (S_IFLNK|S_IRWXUGO), \
+ &proc_pid_link_inode_operations, NULL, \
+ { .proc_get_link = &proc_##OTYPE##_link } )
+#define REG(TYPE, NAME, MODE, OTYPE) \
+ NOD(TYPE, NAME, (S_IFREG|(MODE)), NULL, \
+ &proc_##OTYPE##_operations, {})
+#define INF(TYPE, NAME, MODE, OTYPE) \
+ NOD(TYPE, NAME, (S_IFREG|(MODE)), \
+ NULL, &proc_info_file_operations, \
+ { .proc_read = &proc_##OTYPE } )

-#define E(type,name,mode) {(type),sizeof(name)-1,(name),(mode)}

static struct fs_struct *get_fs_struct(struct task_struct *task)
{
@@ -1298,17 +1326,6 @@ static struct inode_operations proc_fd_i
.lookup = proc_lookupfd,
};

-static struct file_operations proc_task_operations;
-static struct inode_operations proc_task_inode_operations;
-
-#ifdef CONFIG_SECURITY
-static struct file_operations proc_pid_attr_operations;
-static struct file_operations proc_tid_attr_operations;
-static struct inode_operations proc_tid_attr_inode_operations;
-static struct file_operations proc_tgid_attr_operations;
-static struct inode_operations proc_tgid_attr_inode_operations;
-#endif
-
/* SMP-safe */
static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *dentry,
@@ -1326,6 +1343,10 @@ static struct dentry *proc_pident_lookup
if (!task)
goto out_no_task;

+ /*
+ * Yes, it does not scale. And it should not. Don't add
+ * new entries into /proc/<tgid>/ without very good reasons.
+ */
for (p = ents; p->name; p++) {
if (p->len != dentry->d_name.len)
continue;
@@ -1342,163 +1363,13 @@ static struct dentry *proc_pident_lookup

ei = PROC_I(inode);
inode->i_mode = p->mode;
- /*
- * Yes, it does not scale. And it should not. Don't add
- * new entries into /proc/<tgid>/ without very good reasons.
- */
- switch(p->type) {
- case PROC_TGID_TASK:
- inode->i_nlink = 2;
- inode->i_op = &proc_task_inode_operations;
- inode->i_fop = &proc_task_operations;
- break;
- case PROC_TID_FD:
- case PROC_TGID_FD:
- inode->i_nlink = 2;
- inode->i_op = &proc_fd_inode_operations;
- inode->i_fop = &proc_fd_operations;
- break;
- case PROC_TID_EXE:
- case PROC_TGID_EXE:
- inode->i_op = &proc_pid_link_inode_operations;
- ei->op.proc_get_link = proc_exe_link;
- break;
- case PROC_TID_CWD:
- case PROC_TGID_CWD:
- inode->i_op = &proc_pid_link_inode_operations;
- ei->op.proc_get_link = proc_cwd_link;
- break;
- case PROC_TID_ROOT:
- case PROC_TGID_ROOT:
- inode->i_op = &proc_pid_link_inode_operations;
- ei->op.proc_get_link = proc_root_link;
- break;
- case PROC_TID_ENVIRON:
- case PROC_TGID_ENVIRON:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_environ;
- break;
- case PROC_TID_AUXV:
- case PROC_TGID_AUXV:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_auxv;
- break;
- case PROC_TID_STATUS:
- case PROC_TGID_STATUS:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_status;
- break;
- case PROC_TID_STAT:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_tid_stat;
- break;
- case PROC_TGID_STAT:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_tgid_stat;
- break;
- case PROC_TID_CMDLINE:
- case PROC_TGID_CMDLINE:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_cmdline;
- break;
- case PROC_TID_STATM:
- case PROC_TGID_STATM:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_statm;
- break;
- case PROC_TID_MAPS:
- case PROC_TGID_MAPS:
- inode->i_fop = &proc_maps_operations;
- break;
-#ifdef CONFIG_NUMA
- case PROC_TID_NUMA_MAPS:
- case PROC_TGID_NUMA_MAPS:
- inode->i_fop = &proc_numa_maps_operations;
- break;
-#endif
- case PROC_TID_MEM:
- case PROC_TGID_MEM:
- inode->i_fop = &proc_mem_operations;
- break;
-#ifdef CONFIG_SECCOMP
- case PROC_TID_SECCOMP:
- case PROC_TGID_SECCOMP:
- inode->i_fop = &proc_seccomp_operations;
- break;
-#endif /* CONFIG_SECCOMP */
- case PROC_TID_MOUNTS:
- case PROC_TGID_MOUNTS:
- inode->i_fop = &proc_mounts_operations;
- break;
-#ifdef CONFIG_MMU
- case PROC_TID_SMAPS:
- case PROC_TGID_SMAPS:
- inode->i_fop = &proc_smaps_operations;
- break;
-#endif
-#ifdef CONFIG_SECURITY
- case PROC_TID_ATTR:
- inode->i_nlink = 2;
- inode->i_op = &proc_tid_attr_inode_operations;
- inode->i_fop = &proc_tid_attr_operations;
- break;
- case PROC_TGID_ATTR:
- inode->i_nlink = 2;
- inode->i_op = &proc_tgid_attr_inode_operations;
- inode->i_fop = &proc_tgid_attr_operations;
- break;
- case PROC_TID_ATTR_CURRENT:
- case PROC_TGID_ATTR_CURRENT:
- case PROC_TID_ATTR_PREV:
- case PROC_TGID_ATTR_PREV:
- case PROC_TID_ATTR_EXEC:
- case PROC_TGID_ATTR_EXEC:
- case PROC_TID_ATTR_FSCREATE:
- case PROC_TGID_ATTR_FSCREATE:
- inode->i_fop = &proc_pid_attr_operations;
- break;
-#endif
-#ifdef CONFIG_KALLSYMS
- case PROC_TID_WCHAN:
- case PROC_TGID_WCHAN:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_wchan;
- break;
-#endif
-#ifdef CONFIG_SCHEDSTATS
- case PROC_TID_SCHEDSTAT:
- case PROC_TGID_SCHEDSTAT:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_pid_schedstat;
- break;
-#endif
-#ifdef CONFIG_CPUSETS
- case PROC_TID_CPUSET:
- case PROC_TGID_CPUSET:
- inode->i_fop = &proc_cpuset_operations;
- break;
-#endif
- case PROC_TID_OOM_SCORE:
- case PROC_TGID_OOM_SCORE:
- inode->i_fop = &proc_info_file_operations;
- ei->op.proc_read = proc_oom_score;
- break;
- case PROC_TID_OOM_ADJUST:
- case PROC_TGID_OOM_ADJUST:
- inode->i_fop = &proc_oom_adjust_operations;
- break;
-#ifdef CONFIG_AUDITSYSCALL
- case PROC_TID_LOGINUID:
- case PROC_TGID_LOGINUID:
- inode->i_fop = &proc_loginuid_operations;
- break;
-#endif
- default:
- printk("procfs: impossible type (%d)",p->type);
- iput(inode);
- error = ERR_PTR(-EINVAL);
- goto out;
- }
+ if (S_ISDIR(inode->i_mode))
+ inode->i_nlink = 2; /* Use getattr to fix if necessary */
+ if (p->iop)
+ inode->i_op = p->iop;
+ if (p->fop)
+ inode->i_fop = p->fop;
+ ei->op = p->op;
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
@@ -1643,18 +1514,18 @@ static struct file_operations proc_pid_a
};

static struct pid_entry tgid_attr_stuff[] = {
- E(PROC_TGID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
- E(PROC_TGID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
- E(PROC_TGID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
- E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
- {0,0,NULL,0}
+ REG(PROC_TGID_ATTR_CURRENT, "current", S_IRUGO|S_IWUGO, pid_attr),
+ REG(PROC_TGID_ATTR_PREV, "prev", S_IRUGO, pid_attr),
+ REG(PROC_TGID_ATTR_EXEC, "exec", S_IRUGO|S_IWUGO, pid_attr),
+ REG(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IRUGO|S_IWUGO, pid_attr),
+ {}
};
static struct pid_entry tid_attr_stuff[] = {
- E(PROC_TID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUGO),
- E(PROC_TID_ATTR_PREV, "prev", S_IFREG|S_IRUGO),
- E(PROC_TID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUGO),
- E(PROC_TID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
- {0,0,NULL,0}
+ REG(PROC_TID_ATTR_CURRENT, "current", S_IRUGO|S_IWUGO, pid_attr),
+ REG(PROC_TID_ATTR_PREV, "prev", S_IRUGO, pid_attr),
+ REG(PROC_TID_ATTR_EXEC, "exec", S_IRUGO|S_IWUGO, pid_attr),
+ REG(PROC_TID_ATTR_FSCREATE, "fscreate", S_IRUGO|S_IWUGO, pid_attr),
+ {}
};

static int proc_tgid_attr_readdir(struct file * filp,
@@ -1728,48 +1599,51 @@ static struct inode_operations proc_self
/*
* Thread groups
*/
+static struct file_operations proc_task_operations;
+static struct inode_operations proc_task_inode_operations;
+
static struct pid_entry tgid_base_stuff[] = {
- E(PROC_TGID_TASK, "task", S_IFDIR|S_IRUGO|S_IXUGO),
- E(PROC_TGID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
- E(PROC_TGID_ENVIRON, "environ", S_IFREG|S_IRUSR),
- E(PROC_TGID_AUXV, "auxv", S_IFREG|S_IRUSR),
- E(PROC_TGID_STATUS, "status", S_IFREG|S_IRUGO),
- E(PROC_TGID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
- E(PROC_TGID_STAT, "stat", S_IFREG|S_IRUGO),
- E(PROC_TGID_STATM, "statm", S_IFREG|S_IRUGO),
- E(PROC_TGID_MAPS, "maps", S_IFREG|S_IRUGO),
+ DIR(PROC_TGID_TASK, "task", S_IRUGO|S_IXUGO, task),
+ DIR(PROC_TGID_FD, "fd", S_IRUSR|S_IXUSR, fd),
+ INF(PROC_TGID_ENVIRON, "environ", S_IRUSR, pid_environ),
+ INF(PROC_TGID_AUXV, "auxv", S_IRUSR, pid_auxv),
+ INF(PROC_TGID_STATUS, "status", S_IRUGO, pid_status),
+ INF(PROC_TGID_CMDLINE, "cmdline", S_IRUGO, pid_cmdline),
+ INF(PROC_TGID_STAT, "stat", S_IRUGO, tgid_stat),
+ INF(PROC_TGID_STATM, "statm", S_IRUGO, pid_statm),
+ REG(PROC_TGID_MAPS, "maps", S_IRUGO, maps),
#ifdef CONFIG_NUMA
- E(PROC_TGID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
+ REG(PROC_TGID_NUMA_MAPS, "numa_maps", S_IRUGO, numa_maps),
#endif
- E(PROC_TGID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
+ REG(PROC_TGID_MEM, "mem", S_IRUSR|S_IWUSR, mem),
#ifdef CONFIG_SECCOMP
- E(PROC_TGID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
+ REG(PROC_TGID_SECCOMP, "seccomp", S_IRUSR|S_IWUSR, seccomp),
#endif
- E(PROC_TGID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
- E(PROC_TGID_ROOT, "root", S_IFLNK|S_IRWXUGO),
- E(PROC_TGID_EXE, "exe", S_IFLNK|S_IRWXUGO),
- E(PROC_TGID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+ LNK(PROC_TGID_CWD, "cwd", cwd),
+ LNK(PROC_TGID_ROOT, "root", root),
+ LNK(PROC_TGID_EXE, "exe", exe),
+ REG(PROC_TGID_MOUNTS, "mounts", S_IRUGO, mounts),
#ifdef CONFIG_MMU
- E(PROC_TGID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+ REG(PROC_TGID_SMAPS, "smaps", S_IRUGO, smaps),
#endif
#ifdef CONFIG_SECURITY
- E(PROC_TGID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
+ DIR(PROC_TGID_ATTR, "attr", S_IRUGO|S_IXUGO, tgid_attr),
#endif
#ifdef CONFIG_KALLSYMS
- E(PROC_TGID_WCHAN, "wchan", S_IFREG|S_IRUGO),
+ INF(PROC_TGID_WCHAN, "wchan", S_IRUGO, pid_wchan),
#endif
#ifdef CONFIG_SCHEDSTATS
- E(PROC_TGID_SCHEDSTAT, "schedstat", S_IFREG|S_IRUGO),
+ INF(PROC_TGID_SCHEDSTAT, "schedstat", S_IRUGO, pid_schedstat),
#endif
#ifdef CONFIG_CPUSETS
- E(PROC_TGID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
+ REG(PROC_TGID_CPUSET, "cpuset", S_IRUGO, cpuset),
#endif
- E(PROC_TGID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
- E(PROC_TGID_OOM_ADJUST,"oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
+ INF(PROC_TGID_OOM_SCORE, "oom_score", S_IRUGO, oom_score),
+ REG(PROC_TGID_OOM_ADJUST,"oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
#ifdef CONFIG_AUDITSYSCALL
- E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
+ REG(PROC_TGID_LOGINUID, "loginuid", S_IWUSR|S_IRUGO, loginuid),
#endif
- {0,0,NULL,0}
+ {}
};

static int proc_tgid_base_readdir(struct file * filp,
@@ -2050,46 +1924,46 @@ int proc_pid_readdir(struct file * filp,
* Tasks
*/
static struct pid_entry tid_base_stuff[] = {
- E(PROC_TID_FD, "fd", S_IFDIR|S_IRUSR|S_IXUSR),
- E(PROC_TID_ENVIRON, "environ", S_IFREG|S_IRUSR),
- E(PROC_TID_AUXV, "auxv", S_IFREG|S_IRUSR),
- E(PROC_TID_STATUS, "status", S_IFREG|S_IRUGO),
- E(PROC_TID_CMDLINE, "cmdline", S_IFREG|S_IRUGO),
- E(PROC_TID_STAT, "stat", S_IFREG|S_IRUGO),
- E(PROC_TID_STATM, "statm", S_IFREG|S_IRUGO),
- E(PROC_TID_MAPS, "maps", S_IFREG|S_IRUGO),
+ DIR(PROC_TID_FD, "fd", S_IRUSR|S_IXUSR, fd),
+ INF(PROC_TID_ENVIRON, "environ", S_IRUSR, pid_environ),
+ INF(PROC_TID_AUXV, "auxv", S_IRUSR, pid_auxv),
+ INF(PROC_TID_STATUS, "status", S_IRUGO, pid_status),
+ INF(PROC_TID_CMDLINE, "cmdline", S_IRUGO, pid_cmdline),
+ INF(PROC_TID_STAT, "stat", S_IRUGO, tid_stat),
+ INF(PROC_TID_STATM, "statm", S_IRUGO, pid_statm),
+ REG(PROC_TID_MAPS, "maps", S_IRUGO, maps),
#ifdef CONFIG_NUMA
- E(PROC_TID_NUMA_MAPS, "numa_maps", S_IFREG|S_IRUGO),
+ REG(PROC_TID_NUMA_MAPS, "numa_maps", S_IRUGO, numa_maps),
#endif
- E(PROC_TID_MEM, "mem", S_IFREG|S_IRUSR|S_IWUSR),
+ REG(PROC_TID_MEM, "mem", S_IRUSR|S_IWUSR, mem),
#ifdef CONFIG_SECCOMP
- E(PROC_TID_SECCOMP, "seccomp", S_IFREG|S_IRUSR|S_IWUSR),
+ REG(PROC_TID_SECCOMP, "seccomp", S_IRUSR|S_IWUSR, seccomp),
#endif
- E(PROC_TID_CWD, "cwd", S_IFLNK|S_IRWXUGO),
- E(PROC_TID_ROOT, "root", S_IFLNK|S_IRWXUGO),
- E(PROC_TID_EXE, "exe", S_IFLNK|S_IRWXUGO),
- E(PROC_TID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+ LNK(PROC_TID_CWD, "cwd", cwd),
+ LNK(PROC_TID_ROOT, "root", root),
+ LNK(PROC_TID_EXE, "exe", exe),
+ REG(PROC_TID_MOUNTS, "mounts", S_IRUGO, mounts),
#ifdef CONFIG_MMU
- E(PROC_TID_SMAPS, "smaps", S_IFREG|S_IRUGO),
+ REG(PROC_TID_SMAPS, "smaps", S_IRUGO, smaps),
#endif
#ifdef CONFIG_SECURITY
- E(PROC_TID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
+ DIR(PROC_TID_ATTR, "attr", S_IRUGO|S_IXUGO, tid_attr),
#endif
#ifdef CONFIG_KALLSYMS
- E(PROC_TID_WCHAN, "wchan", S_IFREG|S_IRUGO),
+ INF(PROC_TID_WCHAN, "wchan", S_IRUGO, pid_wchan),
#endif
#ifdef CONFIG_SCHEDSTATS
- E(PROC_TID_SCHEDSTAT, "schedstat",S_IFREG|S_IRUGO),
+ INF(PROC_TID_SCHEDSTAT, "schedstat", S_IRUGO, pid_schedstat),
#endif
#ifdef CONFIG_CPUSETS
- E(PROC_TID_CPUSET, "cpuset", S_IFREG|S_IRUGO),
+ REG(PROC_TID_CPUSET, "cpuset", S_IRUGO, cpuset),
#endif
- E(PROC_TID_OOM_SCORE, "oom_score",S_IFREG|S_IRUGO),
- E(PROC_TID_OOM_ADJUST, "oom_adj", S_IFREG|S_IRUGO|S_IWUSR),
+ INF(PROC_TID_OOM_SCORE, "oom_score", S_IRUGO, oom_score),
+ REG(PROC_TID_OOM_ADJUST, "oom_adj", S_IRUGO|S_IWUSR, oom_adjust),
#ifdef CONFIG_AUDITSYSCALL
- E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO),
+ REG(PROC_TID_LOGINUID, "loginuid", S_IWUSR|S_IRUGO, loginuid),
#endif
- {0,0,NULL,0}
+ {}
};

diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index f6b491f..561db5f 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -243,13 +243,15 @@ static inline void kclist_add(struct kco
extern void kclist_add(struct kcore_list *, void *, size_t);
#endif

+union proc_op {
+ int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **);
+ int (*proc_read)(struct task_struct *task, char *page);
+};
+
struct proc_inode {
struct task_ref *tref;
int fd;
- union {
- int (*proc_get_link)(struct inode *, struct dentry **, struct vfsmount **);
- int (*proc_read)(struct task_struct *task, char *page);
- } op;
+ union proc_op op;
struct proc_dir_entry *pde;
struct inode vfs_inode;
};
--
1.2.2.g709a

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Next message: Eric W. Biederman: "[PATCH 20/23] proc: Make the generation of the self symlink tabledriven."
Previous message: Badari Pulavarty: "[PATCH] change b_size to size_t"
In reply to: Eric W. Biederman: "[PATCH 18/23] proc: Reorder the functions in base.c"
Next in thread: Eric W. Biederman: "[PATCH 20/23] proc: Make the generation of the self symlink tabledriven."
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