From: Yipeng Zou <zouyipeng@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/release-management/issues/IC9Q31 -------------------------------- Introduce xcall_select to mark a special syscall. Mark by: echo @$syscall_nr > /proc/$PID/xcall Make sure it has been enabled in xcall before mark. If a system call number is marked, it means there are custom operations for xcall, otherwise it enters normal system call process. Signed-off-by: Yipeng Zou <zouyipeng@huawei.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- fs/proc/base.c | 52 ++++++++++++++++++++++++++++++++++++++----- include/linux/sched.h | 3 ++- kernel/fork.c | 12 ++++++++++ 3 files changed, 60 insertions(+), 7 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 3206960c4bd7..507cc47ab193 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3596,7 +3596,7 @@ static int xcall_show(struct seq_file *m, void *v) { struct inode *inode = m->private; struct task_struct *p; - unsigned int rs, re; + unsigned int rs, re, sc_no; if (!fast_syscall_enabled()) return -EACCES; @@ -3617,7 +3617,16 @@ static int xcall_show(struct seq_file *m, void *v) rs == (re - 1) ? seq_printf(m, "%d,", rs) : seq_printf(m, "%d-%d,", rs, re - 1); } - seq_puts(m, "\n"); + seq_puts(m, "\nAvailable:\n"); + + for (sc_no = 0; sc_no < __NR_syscalls; sc_no++) { + if (p->xcall_select && test_bit(sc_no, p->xcall_select)) { + seq_printf(m, "NR_syscall: %3d: enabled: %d ", + sc_no, test_bit(sc_no, p->xcall_enable)); + seq_printf(m, "xcall_select: %d\n", + test_bit(sc_no, p->xcall_select)); + } + } out: put_task_struct(p); @@ -3631,16 +3640,43 @@ static int xcall_open(struct inode *inode, struct file *filp) static int xcall_enable_one(struct task_struct *p, unsigned int sc_no) { + if (p->xcall_select && test_bit(sc_no, p->xcall_select)) + return -EINVAL; + + if (!bitmap_weight(p->xcall_enable, __NR_syscalls)) { + p->xcall_select = bitmap_zalloc(__NR_syscalls, GFP_KERNEL); + if (!p->xcall_select) + return -ENOMEM; + } + bitmap_set(p->xcall_enable, sc_no, 1); return 0; } static int xcall_disable_one(struct task_struct *p, unsigned int sc_no) { + if (p->xcall_select && test_bit(sc_no, p->xcall_select)) + return -EINVAL; + bitmap_clear(p->xcall_enable, sc_no, 1); return 0; } +static int xcall_select_table(struct task_struct *p, unsigned int sc_no) +{ + if (!p->xcall_select || !test_bit(sc_no, p->xcall_enable)) { + pr_err("Please enable NR_syscall: %d to xcall first.\n", sc_no); + return -EINVAL; + } + + if (test_bit(sc_no, p->xcall_select)) + return -EINVAL; + + bitmap_set(p->xcall_select, sc_no, 1); + + return 0; +} + static ssize_t xcall_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) { @@ -3650,7 +3686,7 @@ static ssize_t xcall_write(struct file *file, const char __user *buf, const size_t maxlen = sizeof(buffer) - 1; unsigned int sc_no = __NR_syscalls; int ret = 0; - int is_clear = 0; + int is_clear = 0, is_switch = 0; if (!fast_syscall_enabled()) return -EACCES; @@ -3665,8 +3701,10 @@ static ssize_t xcall_write(struct file *file, const char __user *buf, if (buffer[0] == '!') is_clear = 1; + else if ((buffer[0] == '@')) + is_switch = 1; - if (kstrtouint(buffer + is_clear, 10, &sc_no)) { + if (kstrtouint(buffer + is_clear + is_switch, 10, &sc_no)) { ret = -EINVAL; goto out; } @@ -3676,9 +3714,11 @@ static ssize_t xcall_write(struct file *file, const char __user *buf, goto out; } - if (!is_clear && !test_bit(sc_no, p->xcall_enable)) + if (is_switch && test_bit(sc_no, p->xcall_enable)) + ret = xcall_select_table(p, sc_no); + else if (!is_switch && !is_clear && !test_bit(sc_no, p->xcall_enable)) ret = xcall_enable_one(p, sc_no); - else if (is_clear && test_bit(sc_no, p->xcall_enable)) + else if (!is_switch && is_clear && test_bit(sc_no, p->xcall_enable)) ret = xcall_disable_one(p, sc_no); else ret = -EINVAL; diff --git a/include/linux/sched.h b/include/linux/sched.h index 18361e35a377..a377bae2064e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1479,10 +1479,11 @@ struct task_struct { #endif #if defined(CONFIG_FAST_SYSCALL) KABI_USE(15, unsigned long *xcall_enable) + KABI_USE(16, unsigned long *xcall_select) #else KABI_RESERVE(15) -#endif KABI_RESERVE(16) +#endif KABI_AUX_PTR(task_struct) /* CPU-specific state of this task: */ diff --git a/kernel/fork.c b/kernel/fork.c index bd7afeb364ab..b884ac9cdece 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -483,6 +483,9 @@ void free_task(struct task_struct *tsk) #ifdef CONFIG_FAST_SYSCALL if (tsk->xcall_enable) bitmap_free(tsk->xcall_enable); + + if (tsk->xcall_select) + bitmap_free(tsk->xcall_select); #endif free_task_struct(tsk); @@ -1016,6 +1019,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #ifdef CONFIG_FAST_SYSCALL tsk->xcall_enable = NULL; + tsk->xcall_select = NULL; #endif return tsk; @@ -2103,6 +2107,14 @@ static __latent_entropy struct task_struct *copy_process( if (current->xcall_enable) bitmap_copy(p->xcall_enable, current->xcall_enable, __NR_syscalls); + + if (current->xcall_select) { + p->xcall_select = bitmap_zalloc(__NR_syscalls, GFP_KERNEL); + if (!p->xcall_select) + goto bad_fork_free; + + bitmap_copy(p->xcall_select, current->xcall_select, __NR_syscalls); + } #endif #ifdef CONFIG_QOS_SCHED_DYNAMIC_AFFINITY -- 2.34.1