From: Hou Tao <houtao1@huawei.com> hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I53R0H CVE: NA backport: openEuler-22.03-LTS --------------------------- fs_file_read_do_trace() uses writable-tracepoint to update f_mode for file read procedure. Also export it to make it being usable for filesystem kernel module. Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: fang wei <fangwei1@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/read_write.c | 33 +++++++++++++++++++++++++++++++++ include/linux/fs.h | 13 +++++++++++++ 2 files changed, 46 insertions(+) diff --git a/fs/read_write.c b/fs/read_write.c index 433ca8ab7c91..d175b5e8d3d3 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1682,5 +1682,38 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out) return 0; } +#ifdef CONFIG_TRACEPOINTS +static void fs_file_read_ctx_init(struct fs_file_read_ctx *ctx, + struct file *filp, loff_t pos) +{ + memset(ctx, 0, sizeof(*ctx)); + ctx->name = file_dentry(filp)->d_name.name; + ctx->f_ctl_mode = filp->f_ctl_mode; + ctx->key = (unsigned long)filp; + ctx->i_size = file_inode(filp)->i_size; + ctx->prev_index = filp->f_ra.prev_pos >> PAGE_SHIFT; + ctx->index = pos >> PAGE_SHIFT; +} + +#define FS_FILE_READ_VERSION 1 +#define FS_FILE_READ_MODE_MASK (FMODE_CTL_RANDOM | FMODE_CTL_WILLNEED) + +void fs_file_read_update_args_by_trace(struct kiocb *iocb) +{ + struct file *filp = iocb->ki_filp; + struct fs_file_read_ctx ctx; + + fs_file_read_ctx_init(&ctx, filp, iocb->ki_pos); + trace_fs_file_read(&ctx, FS_FILE_READ_VERSION); + + if (!ctx.set_f_ctl_mode && !ctx.clr_f_ctl_mode) + return; + + filp->f_ctl_mode |= ctx.set_f_ctl_mode & FS_FILE_READ_MODE_MASK; + filp->f_ctl_mode &= ~(ctx.clr_f_ctl_mode & FS_FILE_READ_MODE_MASK); +} +EXPORT_SYMBOL_GPL(fs_file_read_update_args_by_trace); +#endif + EXPORT_TRACEPOINT_SYMBOL_GPL(fs_file_read); EXPORT_TRACEPOINT_SYMBOL_GPL(fs_file_release); diff --git a/include/linux/fs.h b/include/linux/fs.h index 1ed02fc8bdd0..44ee66086b94 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -41,6 +41,7 @@ #include <linux/build_bug.h> #include <linux/stddef.h> #include <linux/mount.h> +#include <linux/tracepoint-defs.h> #include <asm/byteorder.h> #include <uapi/linux/fs.h> @@ -3579,4 +3580,16 @@ struct fs_file_read_ctx { long long index; }; +#ifdef CONFIG_TRACEPOINTS +DECLARE_TRACEPOINT(fs_file_read); +extern void fs_file_read_update_args_by_trace(struct kiocb *iocb); +#else +static inline void fs_file_read_update_args_by_trace(struct kiocb *iocb) {} +#endif + +static inline void fs_file_read_do_trace(struct kiocb *iocb) +{ + if (tracepoint_enabled(fs_file_read)) + fs_file_read_update_args_by_trace(iocb); +} #endif /* _LINUX_FS_H */ -- 2.20.1