From c2c0bb44620dece7ec97e28167e32c343da22867 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 25 Jun 2015 15:00:54 -0700 Subject: proc: fix PAGE_SIZE limit of /proc/$PID/cmdline /proc/$PID/cmdline truncates output at PAGE_SIZE. It is easy to see with $ cat /proc/self/cmdline $(seq 1037) 2>/dev/null However, command line size was never limited to PAGE_SIZE but to 128 KB and relatively recently limitation was removed altogether. People noticed and ask questions: http://stackoverflow.com/questions/199130/how-do-i-increase-the-proc-pid-cmdline-4096-byte-limit seq file interface is not OK, because it kmalloc's for whole output and open + read(, 1) + sleep will pin arbitrary amounts of kernel memory. To not do that, limit must be imposed which is incompatible with arbitrary sized command lines. I apologize for hairy code, but this it direct consequence of command line layout in memory and hacks to support things like "init [3]". The loops are "unrolled" otherwise it is either macros which hide control flow or functions with 7-8 arguments with equal line count. There should be real setproctitle(2) or something. [akpm@linux-foundation.org: fix a billion min() warnings] Signed-off-by: Alexey Dobriyan Tested-by: Jarod Wilson Acked-by: Jarod Wilson Cc: Cyrill Gorcunov Cc: Jan Stancek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/base.c | 205 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 196 insertions(+), 9 deletions(-) (limited to 'fs') diff --git a/fs/proc/base.c b/fs/proc/base.c index 286a422f440e..bd7a9affc14b 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -196,18 +196,205 @@ static int proc_root_link(struct dentry *dentry, struct path *path) return result; } -static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns, - struct pid *pid, struct task_struct *task) +static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf, + size_t _count, loff_t *pos) { + struct task_struct *tsk; + struct mm_struct *mm; + char *page; + unsigned long count = _count; + unsigned long arg_start, arg_end, env_start, env_end; + unsigned long len1, len2, len; + unsigned long p; + char c; + ssize_t rv; + + BUG_ON(*pos < 0); + + tsk = get_proc_task(file_inode(file)); + if (!tsk) + return -ESRCH; + mm = get_task_mm(tsk); + put_task_struct(tsk); + if (!mm) + return 0; + /* Check if process spawned far enough to have cmdline. */ + if (!mm->env_end) { + rv = 0; + goto out_mmput; + } + + page = (char *)__get_free_page(GFP_TEMPORARY); + if (!page) { + rv = -ENOMEM; + goto out_mmput; + } + + down_read(&mm->mmap_sem); + arg_start = mm->arg_start; + arg_end = mm->arg_end; + env_start = mm->env_start; + env_end = mm->env_end; + up_read(&mm->mmap_sem); + + BUG_ON(arg_start > arg_end); + BUG_ON(env_start > env_end); + + len1 = arg_end - arg_start; + len2 = env_end - env_start; + /* - * Rely on struct seq_operations::show() being called once - * per internal buffer allocation. See single_open(), traverse(). + * Inherently racy -- command line shares address space + * with code and data. */ - BUG_ON(m->size < PAGE_SIZE); - m->count += get_cmdline(task, m->buf, PAGE_SIZE); - return 0; + rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0); + if (rv <= 0) + goto out_free_page; + + rv = 0; + + if (c == '\0') { + /* Command line (set of strings) occupies whole ARGV. */ + if (len1 <= *pos) + goto out_free_page; + + p = arg_start + *pos; + len = len1 - *pos; + while (count > 0 && len > 0) { + unsigned int _count; + int nr_read; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + } + } else { + /* + * Command line (1 string) occupies ARGV and maybe + * extends into ENVP. + */ + if (len1 + len2 <= *pos) + goto skip_argv_envp; + if (len1 <= *pos) + goto skip_argv; + + p = arg_start + *pos; + len = len1 - *pos; + while (count > 0 && len > 0) { + unsigned int _count, l; + int nr_read; + bool final; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + /* + * Command line can be shorter than whole ARGV + * even if last "marker" byte says it is not. + */ + final = false; + l = strnlen(page, nr_read); + if (l < nr_read) { + nr_read = l; + final = true; + } + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + + if (final) + goto out_free_page; + } +skip_argv: + /* + * Command line (1 string) occupies ARGV and + * extends into ENVP. + */ + if (len1 <= *pos) { + p = env_start + *pos - len1; + len = len1 + len2 - *pos; + } else { + p = env_start; + len = len2; + } + while (count > 0 && len > 0) { + unsigned int _count, l; + int nr_read; + bool final; + + _count = min3(count, len, PAGE_SIZE); + nr_read = access_remote_vm(mm, p, page, _count, 0); + if (nr_read < 0) + rv = nr_read; + if (nr_read <= 0) + goto out_free_page; + + /* Find EOS. */ + final = false; + l = strnlen(page, nr_read); + if (l < nr_read) { + nr_read = l; + final = true; + } + + if (copy_to_user(buf, page, nr_read)) { + rv = -EFAULT; + goto out_free_page; + } + + p += nr_read; + len -= nr_read; + buf += nr_read; + count -= nr_read; + rv += nr_read; + + if (final) + goto out_free_page; + } +skip_argv_envp: + ; + } + +out_free_page: + free_page((unsigned long)page); +out_mmput: + mmput(mm); + if (rv > 0) + *pos += rv; + return rv; } +static const struct file_operations proc_pid_cmdline_ops = { + .read = proc_pid_cmdline_read, + .llseek = generic_file_llseek, +}; + static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { @@ -2572,7 +2759,7 @@ static const struct pid_entry tgid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - ONE("cmdline", S_IRUGO, proc_pid_cmdline), + REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), ONE("stat", S_IRUGO, proc_tgid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_pid_maps_operations), @@ -2918,7 +3105,7 @@ static const struct pid_entry tid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - ONE("cmdline", S_IRUGO, proc_pid_cmdline), + REG("cmdline", S_IRUGO, proc_pid_cmdline_ops), ONE("stat", S_IRUGO, proc_tid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_tid_maps_operations), -- cgit v1.2.3-59-g8ed1b From 2e13ba54a2682eea24918b87ad3edf70c2cf085b Mon Sep 17 00:00:00 2001 From: Iago López Galeiras Date: Thu, 25 Jun 2015 15:00:57 -0700 Subject: fs, proc: introduce CONFIG_PROC_CHILDREN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 818411616baf ("fs, proc: introduce /proc//task//children entry") introduced the children entry for checkpoint restore and the file is only available on kernels configured with CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS) because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE. However, the children proc file is useful outside of checkpoint restore. I would like to use it in rkt. The rkt process exec() another program it does not control, and that other program will fork()+exec() a child process. I would like to find the pid of the child process from an external tool without iterating in /proc over all processes to find which one has a parent pid equal to rkt. This commit introduces CONFIG_PROC_CHILDREN and makes CONFIG_CHECKPOINT_RESTORE select it. This allows enabling /proc//task//children without needing to enable CONFIG_CHECKPOINT_RESTORE and CONFIG_EXPERT. Alban tested that /proc//task//children is present when the kernel is configured with CONFIG_PROC_CHILDREN=y but without CONFIG_CHECKPOINT_RESTORE Signed-off-by: Iago López Galeiras Tested-by: Alban Crequy Reviewed-by: Cyrill Gorcunov Cc: Oleg Nesterov Cc: Kees Cook Cc: Pavel Emelyanov Cc: Serge Hallyn Cc: KAMEZAWA Hiroyuki Cc: Alexander Viro Cc: Andy Lutomirski Cc: Djalal Harouni Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/Kconfig | 4 ++++ fs/proc/array.c | 4 ++-- fs/proc/base.c | 2 +- init/Kconfig | 1 + 4 files changed, 8 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index 2183fcf41d59..d751fcb637bb 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -71,3 +71,7 @@ config PROC_PAGE_MONITOR /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap, /proc/kpagecount, and /proc/kpageflags. Disabling these interfaces will reduce the size of the kernel by approximately 4kb. + +config PROC_CHILDREN + bool "Include /proc//task//children file" + default n diff --git a/fs/proc/array.c b/fs/proc/array.c index 3f57dac31ba6..ce065cf3104f 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -577,7 +577,7 @@ int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns, return 0; } -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_PROC_CHILDREN static struct pid * get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos) { @@ -700,4 +700,4 @@ const struct file_operations proc_tid_children_operations = { .llseek = seq_lseek, .release = children_seq_release, }; -#endif /* CONFIG_CHECKPOINT_RESTORE */ +#endif /* CONFIG_PROC_CHILDREN */ diff --git a/fs/proc/base.c b/fs/proc/base.c index bd7a9affc14b..1d540b3f226f 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3109,7 +3109,7 @@ static const struct pid_entry tid_base_stuff[] = { ONE("stat", S_IRUGO, proc_tid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_tid_maps_operations), -#ifdef CONFIG_CHECKPOINT_RESTORE +#ifdef CONFIG_PROC_CHILDREN REG("children", S_IRUGO, proc_tid_children_operations), #endif #ifdef CONFIG_NUMA diff --git a/init/Kconfig b/init/Kconfig index b999fa381bf9..6a930b7494ef 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1131,6 +1131,7 @@ endif # CGROUPS config CHECKPOINT_RESTORE bool "Checkpoint/restore support" if EXPERT + select PROC_CHILDREN default n help Enables additional kernel features in a sake of checkpoint/restore. -- cgit v1.2.3-59-g8ed1b From 81ae394bdc473cafa5074948516fc83b504ea60b Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 25 Jun 2015 15:02:38 -0700 Subject: fs/jbd2/journal.c: use strreplace() In one case, we eliminate a local variable; in the other a strlen() call and some .text. Signed-off-by: Rasmus Villemoes Cc: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/jbd2/journal.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index b96bd8076b70..5c187ded12d6 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1137,7 +1137,6 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev, { journal_t *journal = journal_init_common(); struct buffer_head *bh; - char *p; int n; if (!journal) @@ -1150,9 +1149,7 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev, journal->j_blk_offset = start; journal->j_maxlen = len; bdevname(journal->j_dev, journal->j_devname); - p = journal->j_devname; - while ((p = strchr(p, '/'))) - *p = '!'; + strreplace(journal->j_devname, '/', '!'); jbd2_stats_proc_init(journal); n = journal->j_blocksize / sizeof(journal_block_tag_t); journal->j_wbufsize = n; @@ -1204,10 +1201,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode) journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev; journal->j_inode = inode; bdevname(journal->j_dev, journal->j_devname); - p = journal->j_devname; - while ((p = strchr(p, '/'))) - *p = '!'; - p = journal->j_devname + strlen(journal->j_devname); + p = strreplace(journal->j_devname, '/', '!'); sprintf(p, "-%lu", journal->j_inode->i_ino); jbd_debug(1, "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n", -- cgit v1.2.3-59-g8ed1b From ec3904dc6537fe606b281b368639236296ee7257 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 25 Jun 2015 15:02:41 -0700 Subject: fs/ext4/super.c: use strreplace() in ext4_fill_super() This makes a very large function a little smaller. Signed-off-by: Rasmus Villemoes Cc: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext4/super.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/ext4/super.c b/fs/ext4/super.c index ca9d4a2fed41..5f3c43a66937 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3420,7 +3420,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) unsigned long journal_devnum = 0; unsigned long def_mount_opts; struct inode *root; - char *cp; const char *descr; int ret = -ENOMEM; int blocksize, clustersize; @@ -3456,8 +3455,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) #endif /* Cleanup superblock name */ - for (cp = sb->s_id; (cp = strchr(cp, '/'));) - *cp = '!'; + strreplace(sb->s_id, '/', '!'); /* -EINVAL is default */ ret = -EINVAL; -- cgit v1.2.3-59-g8ed1b From 35a4c902f61fc262aba03d5e8381334683e4d4aa Mon Sep 17 00:00:00 2001 From: Firo Yang Date: Thu, 25 Jun 2015 15:03:32 -0700 Subject: fs/efs: femove unneeded cast kmem_cache_alloc() returns void*. Signed-off-by: Firo Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/efs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/efs/super.c b/fs/efs/super.c index 7fca462ea4e3..c8411a30f7da 100644 --- a/fs/efs/super.c +++ b/fs/efs/super.c @@ -67,7 +67,7 @@ static struct kmem_cache * efs_inode_cachep; static struct inode *efs_alloc_inode(struct super_block *sb) { struct efs_inode_info *ei; - ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); + ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; -- cgit v1.2.3-59-g8ed1b From 83b08bf7defa702cc6ef975fb05c437cd331826c Mon Sep 17 00:00:00 2001 From: Firo Yang Date: Thu, 25 Jun 2015 15:03:40 -0700 Subject: fs/minix: remove unneeded cast kmem_cache_alloc() returns void*. Signed-off-by: Firo Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/minix/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/minix/inode.c b/fs/minix/inode.c index 1182d1e26a9c..086cd0a61e80 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -62,7 +62,7 @@ static struct kmem_cache * minix_inode_cachep; static struct inode *minix_alloc_inode(struct super_block *sb) { struct minix_inode_info *ei; - ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL); + ei = kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; -- cgit v1.2.3-59-g8ed1b From 9f0f564abbd8812edeef2c839ab3e6ba16595491 Mon Sep 17 00:00:00 2001 From: Fabian Frederick Date: Thu, 25 Jun 2015 15:03:43 -0700 Subject: fs/befs/btree.c: remove unneeded initializations bh, od_sup and this_node are unconditionally initialized in befs_bt_read_super() and befs_btree_find() Signed-off-by: Fabian Frederick Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/befs/btree.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/befs/btree.c b/fs/befs/btree.c index 0826e91dacda..22c166280883 100644 --- a/fs/befs/btree.c +++ b/fs/befs/btree.c @@ -137,8 +137,8 @@ static int befs_bt_read_super(struct super_block *sb, befs_data_stream * ds, befs_btree_super * sup) { - struct buffer_head *bh = NULL; - befs_disk_btree_super *od_sup = NULL; + struct buffer_head *bh; + befs_disk_btree_super *od_sup; befs_debug(sb, "---> %s", __func__); @@ -250,7 +250,7 @@ int befs_btree_find(struct super_block *sb, befs_data_stream * ds, const char *key, befs_off_t * value) { - struct befs_btree_node *this_node = NULL; + struct befs_btree_node *this_node; befs_btree_super bt_super; befs_off_t node_off; int res; -- cgit v1.2.3-59-g8ed1b From f73c2f1f83ca1c4e2f4515f987973bfe56c86973 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 25 Jun 2015 15:03:45 -0700 Subject: NILFS2: support NFSv2 export The "fh_len" passed to ->fh_to_* is not guaranteed to be that same as that returned by encode_fh - it may be larger. With NFSv2, the filehandle is fixed length, so it may appear longer than expected and be zero-padded. So we must test that fh_len is at least some value, not exactly equal to it. Signed-off-by: NeilBrown Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/namei.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 22180836ec22..37dd6b05b1b5 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -496,8 +496,7 @@ static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh, { struct nilfs_fid *fid = (struct nilfs_fid *)fh; - if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE && - fh_len != NILFS_FID_SIZE_CONNECTABLE) || + if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE || (fh_type != FILEID_NILFS_WITH_PARENT && fh_type != FILEID_NILFS_WITHOUT_PARENT)) return NULL; @@ -510,7 +509,7 @@ static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh, { struct nilfs_fid *fid = (struct nilfs_fid *)fh; - if (fh_len != NILFS_FID_SIZE_CONNECTABLE || + if (fh_len < NILFS_FID_SIZE_CONNECTABLE || fh_type != FILEID_NILFS_WITH_PARENT) return NULL; -- cgit v1.2.3-59-g8ed1b From 89bfae43c8999344c3025802a3652ac42f55278e Mon Sep 17 00:00:00 2001 From: Firo Yang Date: Thu, 25 Jun 2015 15:03:48 -0700 Subject: fs/reiserfs: remove unneeded cast kmem_cache_alloc() returns void*. Signed-off-by: Firo Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/reiserfs/super.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index 0111ad0466ed..d766bfac06cb 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -588,8 +588,7 @@ static struct kmem_cache *reiserfs_inode_cachep; static struct inode *reiserfs_alloc_inode(struct super_block *sb) { struct reiserfs_inode_info *ei; - ei = (struct reiserfs_inode_info *) - kmem_cache_alloc(reiserfs_inode_cachep, GFP_KERNEL); + ei = kmem_cache_alloc(reiserfs_inode_cachep, GFP_KERNEL); if (!ei) return NULL; atomic_set(&ei->openers, 0); -- cgit v1.2.3-59-g8ed1b From 5202efe544c279be152f44f2821010ff7b2d7e5b Mon Sep 17 00:00:00 2001 From: Nicolas Iooss Date: Thu, 25 Jun 2015 15:03:51 -0700 Subject: coredump: use from_kuid/kgid when formatting corename When adding __printf attribute to cn_printf, gcc reports some issues: fs/coredump.c:213:5: warning: format '%d' expects argument of type 'int', but argument 3 has type 'kuid_t' [-Wformat=] err = cn_printf(cn, "%d", cred->uid); ^ fs/coredump.c:217:5: warning: format '%d' expects argument of type 'int', but argument 3 has type 'kgid_t' [-Wformat=] err = cn_printf(cn, "%d", cred->gid); ^ These warnings come from the fact that the value of uid/gid needs to be extracted from the kuid_t/kgid_t structure before being used as an integer. More precisely, cred->uid and cred->gid need to be converted to either user-namespace uid/gid or to init_user_ns uid/gid. Use init_user_ns in order not to break existing ABI, and document this in Documentation/sysctl/kernel.txt. While at it, format uid and gid values with %u instead of %d because uid_t/__kernel_uid32_t and gid_t/__kernel_gid32_t are unsigned int. Signed-off-by: Nicolas Iooss Acked-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/kernel.txt | 4 ++-- fs/coredump.c | 8 ++++++-- 2 files changed, 8 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index e5d528e0c46e..6fccb69c03e7 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -197,8 +197,8 @@ core_pattern is used to specify a core dumpfile pattern name. %P global pid (init PID namespace) %i tid %I global tid (init PID namespace) - %u uid - %g gid + %u uid (in initial user namespace) + %g gid (in initial user namespace) %d dump mode, matches PR_SET_DUMPABLE and /proc/sys/fs/suid_dumpable %s signal number diff --git a/fs/coredump.c b/fs/coredump.c index bbbe139ab280..833a57bc856c 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -209,11 +209,15 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm) break; /* uid */ case 'u': - err = cn_printf(cn, "%d", cred->uid); + err = cn_printf(cn, "%u", + from_kuid(&init_user_ns, + cred->uid)); break; /* gid */ case 'g': - err = cn_printf(cn, "%d", cred->gid); + err = cn_printf(cn, "%u", + from_kgid(&init_user_ns, + cred->gid)); break; case 'd': err = cn_printf(cn, "%d", -- cgit v1.2.3-59-g8ed1b From b4176b7c135ed28e78752552358919e5b14ad2bf Mon Sep 17 00:00:00 2001 From: Nicolas Iooss Date: Thu, 25 Jun 2015 15:03:53 -0700 Subject: coredump: add __printf attribute to cn_*printf functions This allows detecting improper format string at build time, like: fs/coredump.c:225:5: warning: format '%ld' expects argument of type 'long int', but argument 3 has type 'int' [-Wformat=] err = cn_printf(cn, "%ld", cprm->siginfo->si_signo); ^ As si_signo is always an int, the format should be %d here. Signed-off-by: Nicolas Iooss Acked-by: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/coredump.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/coredump.c b/fs/coredump.c index 833a57bc856c..e52e0064feac 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -70,7 +70,8 @@ static int expand_corename(struct core_name *cn, int size) return 0; } -static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg) +static __printf(2, 0) int cn_vprintf(struct core_name *cn, const char *fmt, + va_list arg) { int free, need; va_list arg_copy; @@ -93,7 +94,7 @@ again: return -ENOMEM; } -static int cn_printf(struct core_name *cn, const char *fmt, ...) +static __printf(2, 3) int cn_printf(struct core_name *cn, const char *fmt, ...) { va_list arg; int ret; @@ -105,7 +106,8 @@ static int cn_printf(struct core_name *cn, const char *fmt, ...) return ret; } -static int cn_esc_printf(struct core_name *cn, const char *fmt, ...) +static __printf(2, 3) +int cn_esc_printf(struct core_name *cn, const char *fmt, ...) { int cur = cn->used; va_list arg; @@ -225,7 +227,8 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm) break; /* signal that caused the coredump */ case 's': - err = cn_printf(cn, "%ld", cprm->siginfo->si_signo); + err = cn_printf(cn, "%d", + cprm->siginfo->si_signo); break; /* UNIX time of coredump */ case 't': { -- cgit v1.2.3-59-g8ed1b