cregit-Linux how code gets into the kernel

Release 4.10 fs/proc/fd.c

Directory: fs/proc
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/dcache.h>
#include <linux/path.h>
#include <linux/fdtable.h>
#include <linux/namei.h>
#include <linux/pid.h>
#include <linux/security.h>
#include <linux/file.h>
#include <linux/seq_file.h>
#include <linux/fs.h>

#include <linux/proc_fs.h>

#include "../mount.h"
#include "internal.h"
#include "fd.h"


static int seq_show(struct seq_file *m, void *v) { struct files_struct *files = NULL; int f_flags = 0, ret = -ENOENT; struct file *file = NULL; struct task_struct *task; task = get_proc_task(m->private); if (!task) return -ENOENT; files = get_files_struct(task); put_task_struct(task); if (files) { unsigned int fd = proc_fd(m->private); spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { struct fdtable *fdt = files_fdtable(files); f_flags = file->f_flags; if (close_on_exec(fd, fdt)) f_flags |= O_CLOEXEC; get_file(file); ret = 0; } spin_unlock(&files->file_lock); put_files_struct(files); } if (ret) return ret; seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", (long long)file->f_pos, f_flags, real_mount(file->f_path.mnt)->mnt_id); show_fd_locks(m, file, files); if (seq_has_overflowed(m)) goto out; if (file->f_op->show_fdinfo) file->f_op->show_fdinfo(m, file); out: fput(file); return 0; }

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cyrill gorcunovcyrill gorcunov21084.68%350.00%
andrey vaginandrey vagin3714.92%233.33%
alexey dobriyanalexey dobriyan10.40%116.67%
Total248100.00%6100.00%


static int seq_fdinfo_open(struct inode *inode, struct file *file) { return single_open(file, seq_show, inode); }

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cyrill gorcunovcyrill gorcunov26100.00%2100.00%
Total26100.00%2100.00%

static const struct file_operations proc_fdinfo_file_operations = { .open = seq_fdinfo_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, };
static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) { struct files_struct *files; struct task_struct *task; const struct cred *cred; struct inode *inode; unsigned int fd; if (flags & LOOKUP_RCU) return -ECHILD; inode = d_inode(dentry); task = get_proc_task(inode); fd = proc_fd(inode); if (task) { files = get_files_struct(task); if (files) { struct file *file; rcu_read_lock(); file = fcheck_files(files, fd); if (file) { unsigned f_mode = file->f_mode; rcu_read_unlock(); put_files_struct(files); if (task_dumpable(task)) { rcu_read_lock(); cred = __task_cred(task); inode->i_uid = cred->euid; inode->i_gid = cred->egid; rcu_read_unlock(); } else { inode->i_uid = GLOBAL_ROOT_UID; inode->i_gid = GLOBAL_ROOT_GID; } if (S_ISLNK(inode->i_mode)) { unsigned i_mode = S_IFLNK; if (f_mode & FMODE_READ) i_mode |= S_IRUSR | S_IXUSR; if (f_mode & FMODE_WRITE) i_mode |= S_IWUSR | S_IXUSR; inode->i_mode = i_mode; } security_task_to_inode(task, inode); put_task_struct(task); return 1; } rcu_read_unlock(); put_files_struct(files); } put_task_struct(task); } return 0; }

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cyrill gorcunovcyrill gorcunov25498.45%133.33%
david howellsdavid howells31.16%133.33%
alexey dobriyanalexey dobriyan10.39%133.33%
Total258100.00%3100.00%

static const struct dentry_operations tid_fd_dentry_operations = { .d_revalidate = tid_fd_revalidate, .d_delete = pid_delete_dentry, };
static int proc_fd_link(struct dentry *dentry, struct path *path) { struct files_struct *files = NULL; struct task_struct *task; int ret = -ENOENT; task = get_proc_task(d_inode(dentry)); if (task) { files = get_files_struct(task); put_task_struct(task); } if (files) { unsigned int fd = proc_fd(d_inode(dentry)); struct file *fd_file; spin_lock(&files->file_lock); fd_file = fcheck_files(files, fd); if (fd_file) { *path = fd_file->f_path; path_get(&fd_file->f_path); ret = 0; } spin_unlock(&files->file_lock); put_files_struct(files); } return ret; }

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cyrill gorcunovcyrill gorcunov13695.10%250.00%
david howellsdavid howells64.20%125.00%
alexey dobriyanalexey dobriyan10.70%125.00%
Total143100.00%4100.00%


static int proc_fd_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { unsigned fd = (unsigned long)ptr; struct proc_inode *ei; struct inode *inode; inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK); if (!inode) goto out; ei = PROC_I(inode); ei->fd = fd; inode->i_op = &proc_pid_link_inode_operations; inode->i_size = 64; ei->op.proc_get_link = proc_fd_link; d_set_d_op(dentry, &tid_fd_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, 0)) return 0; out: return -ENOENT; }

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cyrill gorcunovcyrill gorcunov12694.03%133.33%
al viroal viro64.48%133.33%
andreas gruenbacherandreas gruenbacher21.49%133.33%
Total134100.00%3100.00%


static struct dentry *proc_lookupfd_common(struct inode *dir, struct dentry *dentry, instantiate_t instantiate) { struct task_struct *task = get_proc_task(dir); int result = -ENOENT; unsigned fd = name_to_int(&dentry->d_name); if (!task) goto out_no_task; if (fd == ~0U) goto out; result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); out: put_task_struct(task); out_no_task: return ERR_PTR(result); }

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PersonTokensPropCommitsCommitProp
cyrill gorcunovcyrill gorcunov9593.14%133.33%
al viroal viro43.92%133.33%
alexey dobriyanalexey dobriyan32.94%133.33%
Total102100.00%3100.00%


static int proc_readfd_common(struct file *file, struct dir_context *ctx, instantiate_t instantiate) { struct task_struct *p = get_proc_task(file_inode(file)); struct files_struct *files; unsigned int fd; if (!p) return -ENOENT; if (!dir_emit_dots(file, ctx)) goto out; files = get_files_struct(p); if (!files) goto out; rcu_read_lock(); for (fd = ctx->pos - 2; fd < files_fdtable(files)->max_fds; fd++, ctx->pos++) { char name[PROC_NUMBUF]; int len; if (!fcheck_files(files, fd)) continue; rcu_read_unlock(); len = snprintf(name, sizeof(name), "%u", fd); if (!proc_fill_cache(file, ctx, name, len, instantiate, p, (void *)(unsigned long)fd)) goto out_fd_loop; cond_resched(); rcu_read_lock(); } rcu_read_unlock(); out_fd_loop: put_files_struct(files); out: put_task_struct(p); return 0; }

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cyrill gorcunovcyrill gorcunov17685.44%125.00%
al viroal viro2612.62%125.00%
eric dumazeteric dumazet31.46%125.00%
alexey dobriyanalexey dobriyan10.49%125.00%
Total206100.00%4100.00%


static int proc_readfd(struct file *file, struct dir_context *ctx) { return proc_readfd_common(file, ctx, proc_fd_instantiate); }

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cyrill gorcunovcyrill gorcunov2076.92%150.00%
al viroal viro623.08%150.00%
Total26100.00%2100.00%

const struct file_operations proc_fd_operations = { .read = generic_read_dir, .iterate_shared = proc_readfd, .llseek = generic_file_llseek, };
static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, unsigned int flags) { return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); }

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cyrill gorcunovcyrill gorcunov32100.00%1100.00%
Total32100.00%1100.00%

/* * /proc/pid/fd needs a special permission handler so that a process can still * access /proc/self/fd after it has executed a setuid(). */
int proc_fd_permission(struct inode *inode, int mask) { struct task_struct *p; int rv; rv = generic_permission(inode, mask); if (rv == 0) return rv; rcu_read_lock(); p = pid_task(proc_pid(inode), PIDTYPE_PID); if (p && same_thread_group(p, current)) rv = 0; rcu_read_unlock(); return rv; }

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cyrill gorcunovcyrill gorcunov4256.00%150.00%
oleg nesterovoleg nesterov3344.00%150.00%
Total75100.00%2100.00%

const struct inode_operations proc_fd_inode_operations = { .lookup = proc_lookupfd, .permission = proc_fd_permission, .setattr = proc_setattr, };
static int proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry, struct task_struct *task, const void *ptr) { unsigned fd = (unsigned long)ptr; struct proc_inode *ei; struct inode *inode; inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR); if (!inode) goto out; ei = PROC_I(inode); ei->fd = fd; inode->i_fop = &proc_fdinfo_file_operations; d_set_d_op(dentry, &tid_fd_dentry_operations); d_add(dentry, inode); /* Close the race of the process dying before we return the dentry */ if (tid_fd_revalidate(dentry, 0)) return 0; out: return -ENOENT; }

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cyrill gorcunovcyrill gorcunov11291.80%133.33%
al viroal viro64.92%133.33%
andreas gruenbacherandreas gruenbacher43.28%133.33%
Total122100.00%3100.00%


static struct dentry * proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags) { return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); }

Contributors

PersonTokensPropCommitsCommitProp
cyrill gorcunovcyrill gorcunov32100.00%1100.00%
Total32100.00%1100.00%


static int proc_readfdinfo(struct file *file, struct dir_context *ctx) { return proc_readfd_common(file, ctx, proc_fdinfo_instantiate); }

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PersonTokensPropCommitsCommitProp
cyrill gorcunovcyrill gorcunov2076.92%150.00%
al viroal viro623.08%150.00%
Total26100.00%2100.00%

const struct inode_operations proc_fdinfo_inode_operations = { .lookup = proc_lookupfdinfo, .setattr = proc_setattr, }; const struct file_operations proc_fdinfo_operations = { .read = generic_read_dir, .iterate_shared = proc_readfdinfo, .llseek = generic_file_llseek, };

Overall Contributors

PersonTokensPropCommitsCommitProp
cyrill gorcunovcyrill gorcunov144690.09%321.43%
al viroal viro583.61%321.43%
andrey vaginandrey vagin432.68%214.29%
oleg nesterovoleg nesterov332.06%17.14%
david howellsdavid howells90.56%17.14%
alexey dobriyanalexey dobriyan70.44%214.29%
andreas gruenbacherandreas gruenbacher60.37%17.14%
eric dumazeteric dumazet30.19%17.14%
Total1605100.00%14100.00%
Directory: fs/proc
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