From: Hou Tao houtao1@huawei.com
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8O4U8 CVE: NA
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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
Conflicts: include/linux/fs.h
Signed-off-by: ZhaoLong Wang wangzhaolong1@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 e86d268d3ec8..c22965634f54 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1721,5 +1721,38 @@ 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 = i_size_read(file_inode(filp)); + 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 b4e003026fe5..839f2a6dacd6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -43,6 +43,7 @@ #include <linux/cred.h> #include <linux/mnt_idmapping.h> #include <linux/slab.h> +#include <linux/tracepoint-defs.h>
#include <asm/byteorder.h> #include <uapi/linux/fs.h> @@ -3403,4 +3404,16 @@ 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 */