From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- net/sunrpc/debugfs.c | 309 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 309 insertions(+) create mode 100644 net/sunrpc/debugfs.c (limited to 'net/sunrpc/debugfs.c') diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c new file mode 100644 index 000000000..32417db34 --- /dev/null +++ b/net/sunrpc/debugfs.c @@ -0,0 +1,309 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * debugfs interface for sunrpc + * + * (c) 2014 Jeff Layton + */ + +#include +#include +#include + +#include "netns.h" +#include "fail.h" + +static struct dentry *topdir; +static struct dentry *rpc_clnt_dir; +static struct dentry *rpc_xprt_dir; + +static int +tasks_show(struct seq_file *f, void *v) +{ + u32 xid = 0; + struct rpc_task *task = v; + struct rpc_clnt *clnt = task->tk_client; + const char *rpc_waitq = "none"; + + if (RPC_IS_QUEUED(task)) + rpc_waitq = rpc_qname(task->tk_waitqueue); + + if (task->tk_rqstp) + xid = be32_to_cpu(task->tk_rqstp->rq_xid); + + seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n", + task->tk_pid, task->tk_flags, task->tk_status, + clnt->cl_clid, xid, rpc_task_timeout(task), task->tk_ops, + clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task), + task->tk_action, rpc_waitq); + return 0; +} + +static void * +tasks_start(struct seq_file *f, loff_t *ppos) + __acquires(&clnt->cl_lock) +{ + struct rpc_clnt *clnt = f->private; + loff_t pos = *ppos; + struct rpc_task *task; + + spin_lock(&clnt->cl_lock); + list_for_each_entry(task, &clnt->cl_tasks, tk_task) + if (pos-- == 0) + return task; + return NULL; +} + +static void * +tasks_next(struct seq_file *f, void *v, loff_t *pos) +{ + struct rpc_clnt *clnt = f->private; + struct rpc_task *task = v; + struct list_head *next = task->tk_task.next; + + ++*pos; + + /* If there's another task on list, return it */ + if (next == &clnt->cl_tasks) + return NULL; + return list_entry(next, struct rpc_task, tk_task); +} + +static void +tasks_stop(struct seq_file *f, void *v) + __releases(&clnt->cl_lock) +{ + struct rpc_clnt *clnt = f->private; + spin_unlock(&clnt->cl_lock); + seq_printf(f, "clnt[%pISpc] RPC tasks[%d]\n", + (struct sockaddr *)&clnt->cl_xprt->addr, + atomic_read(&clnt->cl_task_count)); +} + +static const struct seq_operations tasks_seq_operations = { + .start = tasks_start, + .next = tasks_next, + .stop = tasks_stop, + .show = tasks_show, +}; + +static int tasks_open(struct inode *inode, struct file *filp) +{ + int ret = seq_open(filp, &tasks_seq_operations); + if (!ret) { + struct seq_file *seq = filp->private_data; + struct rpc_clnt *clnt = seq->private = inode->i_private; + + if (!refcount_inc_not_zero(&clnt->cl_count)) { + seq_release(inode, filp); + ret = -EINVAL; + } + } + + return ret; +} + +static int +tasks_release(struct inode *inode, struct file *filp) +{ + struct seq_file *seq = filp->private_data; + struct rpc_clnt *clnt = seq->private; + + rpc_release_client(clnt); + return seq_release(inode, filp); +} + +static const struct file_operations tasks_fops = { + .owner = THIS_MODULE, + .open = tasks_open, + .read = seq_read, + .llseek = seq_lseek, + .release = tasks_release, +}; + +static int do_xprt_debugfs(struct rpc_clnt *clnt, struct rpc_xprt *xprt, void *numv) +{ + int len; + char name[24]; /* enough for "../../rpc_xprt/ + 8 hex digits + NULL */ + char link[9]; /* enough for 8 hex digits + NULL */ + int *nump = numv; + + if (IS_ERR_OR_NULL(xprt->debugfs)) + return 0; + len = snprintf(name, sizeof(name), "../../rpc_xprt/%s", + xprt->debugfs->d_name.name); + if (len >= sizeof(name)) + return -1; + if (*nump == 0) + strcpy(link, "xprt"); + else { + len = snprintf(link, sizeof(link), "xprt%d", *nump); + if (len >= sizeof(link)) + return -1; + } + debugfs_create_symlink(link, clnt->cl_debugfs, name); + (*nump)++; + return 0; +} + +void +rpc_clnt_debugfs_register(struct rpc_clnt *clnt) +{ + int len; + char name[9]; /* enough for 8 hex digits + NULL */ + int xprtnum = 0; + + len = snprintf(name, sizeof(name), "%x", clnt->cl_clid); + if (len >= sizeof(name)) + return; + + /* make the per-client dir */ + clnt->cl_debugfs = debugfs_create_dir(name, rpc_clnt_dir); + + /* make tasks file */ + debugfs_create_file("tasks", S_IFREG | 0400, clnt->cl_debugfs, clnt, + &tasks_fops); + + rpc_clnt_iterate_for_each_xprt(clnt, do_xprt_debugfs, &xprtnum); +} + +void +rpc_clnt_debugfs_unregister(struct rpc_clnt *clnt) +{ + debugfs_remove_recursive(clnt->cl_debugfs); + clnt->cl_debugfs = NULL; +} + +static int +xprt_info_show(struct seq_file *f, void *v) +{ + struct rpc_xprt *xprt = f->private; + + seq_printf(f, "netid: %s\n", xprt->address_strings[RPC_DISPLAY_NETID]); + seq_printf(f, "addr: %s\n", xprt->address_strings[RPC_DISPLAY_ADDR]); + seq_printf(f, "port: %s\n", xprt->address_strings[RPC_DISPLAY_PORT]); + seq_printf(f, "state: 0x%lx\n", xprt->state); + seq_printf(f, "netns: %u\n", xprt->xprt_net->ns.inum); + + if (xprt->ops->get_srcaddr) { + int ret, buflen; + char buf[INET6_ADDRSTRLEN]; + + buflen = ARRAY_SIZE(buf); + ret = xprt->ops->get_srcaddr(xprt, buf, buflen); + if (ret < 0) + ret = sprintf(buf, ""); + seq_printf(f, "saddr: %.*s\n", ret, buf); + } + return 0; +} + +static int +xprt_info_open(struct inode *inode, struct file *filp) +{ + int ret; + struct rpc_xprt *xprt = inode->i_private; + + ret = single_open(filp, xprt_info_show, xprt); + + if (!ret) { + if (!xprt_get(xprt)) { + single_release(inode, filp); + ret = -EINVAL; + } + } + return ret; +} + +static int +xprt_info_release(struct inode *inode, struct file *filp) +{ + struct rpc_xprt *xprt = inode->i_private; + + xprt_put(xprt); + return single_release(inode, filp); +} + +static const struct file_operations xprt_info_fops = { + .owner = THIS_MODULE, + .open = xprt_info_open, + .read = seq_read, + .llseek = seq_lseek, + .release = xprt_info_release, +}; + +void +rpc_xprt_debugfs_register(struct rpc_xprt *xprt) +{ + int len, id; + static atomic_t cur_id; + char name[9]; /* 8 hex digits + NULL term */ + + id = (unsigned int)atomic_inc_return(&cur_id); + + len = snprintf(name, sizeof(name), "%x", id); + if (len >= sizeof(name)) + return; + + /* make the per-client dir */ + xprt->debugfs = debugfs_create_dir(name, rpc_xprt_dir); + + /* make tasks file */ + debugfs_create_file("info", S_IFREG | 0400, xprt->debugfs, xprt, + &xprt_info_fops); +} + +void +rpc_xprt_debugfs_unregister(struct rpc_xprt *xprt) +{ + debugfs_remove_recursive(xprt->debugfs); + xprt->debugfs = NULL; +} + +#if IS_ENABLED(CONFIG_FAIL_SUNRPC) +struct fail_sunrpc_attr fail_sunrpc = { + .attr = FAULT_ATTR_INITIALIZER, +}; +EXPORT_SYMBOL_GPL(fail_sunrpc); + +static void fail_sunrpc_init(void) +{ + struct dentry *dir; + + dir = fault_create_debugfs_attr("fail_sunrpc", NULL, + &fail_sunrpc.attr); + + debugfs_create_bool("ignore-client-disconnect", S_IFREG | 0600, dir, + &fail_sunrpc.ignore_client_disconnect); + + debugfs_create_bool("ignore-server-disconnect", S_IFREG | 0600, dir, + &fail_sunrpc.ignore_server_disconnect); + + debugfs_create_bool("ignore-cache-wait", S_IFREG | 0600, dir, + &fail_sunrpc.ignore_cache_wait); +} +#else +static void fail_sunrpc_init(void) +{ +} +#endif + +void __exit +sunrpc_debugfs_exit(void) +{ + debugfs_remove_recursive(topdir); + topdir = NULL; + rpc_clnt_dir = NULL; + rpc_xprt_dir = NULL; +} + +void __init +sunrpc_debugfs_init(void) +{ + topdir = debugfs_create_dir("sunrpc", NULL); + + rpc_clnt_dir = debugfs_create_dir("rpc_clnt", topdir); + + rpc_xprt_dir = debugfs_create_dir("rpc_xprt", topdir); + + fail_sunrpc_init(); +} -- cgit v1.3.1