From 06f9d4f94a075285d25253edbf57f2cda07d4ff3 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 22 Mar 2006 00:07:40 -0800 Subject: [PATCH] unshare: Error if passed unsupported flags A bare bones trivial patch to ensure we always get -EINVAL on the unsupported cases for sys_unshare. If this goes in before 2.6.16 it allows us to forward compatible with future applications using sys_unshare. Signed-off-by: Eric W. Biederman Cc: JANAK DESAI Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index b373322ca497..9bd7b65ee418 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1534,6 +1534,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) check_unshare_flags(&unshare_flags); + /* Return -EINVAL for all unsupported flags */ + err = -EINVAL; + if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| + CLONE_VM|CLONE_FILES|CLONE_SYSVSEM)) + goto bad_unshare_out; + if ((err = unshare_thread(unshare_flags))) goto bad_unshare_out; if ((err = unshare_fs(unshare_flags, &new_fs))) -- cgit v1.2.2 From 0c9e63fd38a2fb2181668a0cdd622a3c23cfd567 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 23 Mar 2006 03:00:12 -0800 Subject: [PATCH] Shrinks sizeof(files_struct) and better layout 1) Reduce the size of (struct fdtable) to exactly 64 bytes on 32bits platforms, lowering kmalloc() allocated space by 50%. 2) Reduce the size of (files_struct), using a special 32 bits (or 64bits) embedded_fd_set, instead of a 1024 bits fd_set for the close_on_exec_init and open_fds_init fields. This save some ram (248 bytes per task) as most tasks dont open more than 32 files. D-Cache footprint for such tasks is also reduced to the minimum. 3) Reduce size of allocated fdset. Currently two full pages are allocated, that is 32768 bits on x86 for example, and way too much. The minimum is now L1_CACHE_BYTES. UP and SMP should benefit from this patch, because most tasks will touch only one cache line when open()/close() stdin/stdout/stderr (0/1/2), (next_fd, close_on_exec_init, open_fds_init, fd_array[0 .. 2] being in the same cache line) Signed-off-by: Eric Dumazet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 9bd7b65ee418..c79ae0b19a49 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -607,12 +607,12 @@ static struct files_struct *alloc_files(void) atomic_set(&newf->count, 1); spin_lock_init(&newf->file_lock); + newf->next_fd = 0; fdt = &newf->fdtab; - fdt->next_fd = 0; fdt->max_fds = NR_OPEN_DEFAULT; - fdt->max_fdset = __FD_SETSIZE; - fdt->close_on_exec = &newf->close_on_exec_init; - fdt->open_fds = &newf->open_fds_init; + fdt->max_fdset = EMBEDDED_FD_SET_SIZE; + fdt->close_on_exec = (fd_set *)&newf->close_on_exec_init; + fdt->open_fds = (fd_set *)&newf->open_fds_init; fdt->fd = &newf->fd_array[0]; INIT_RCU_HEAD(&fdt->rcu); fdt->free_files = NULL; -- cgit v1.2.2 From 2056a782f8e7e65fd4bfd027506b4ce1c5e9ccd4 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 23 Mar 2006 20:00:26 +0100 Subject: [PATCH] Block queue IO tracing support (blktrace) as of 2006-03-23 Signed-off-by: Jens Axboe --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index c79ae0b19a49..c21bae8c93b9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -181,6 +181,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) /* One for us, one for whoever does the "release_task()" (usually parent) */ atomic_set(&tsk->usage,2); atomic_set(&tsk->fs_excl, 0); + tsk->btrace_seq = 0; return tsk; } -- cgit v1.2.2