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 --- fs/jfs/jfs_debug.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 fs/jfs/jfs_debug.c (limited to 'fs/jfs/jfs_debug.c') diff --git a/fs/jfs/jfs_debug.c b/fs/jfs/jfs_debug.c new file mode 100644 index 000000000..44b62b3c3 --- /dev/null +++ b/fs/jfs/jfs_debug.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) International Business Machines Corp., 2000-2004 + * Portions Copyright (C) Christoph Hellwig, 2001-2002 + */ + +#include +#include +#include +#include +#include +#include +#include "jfs_incore.h" +#include "jfs_filsys.h" +#include "jfs_debug.h" + +#ifdef PROC_FS_JFS /* see jfs_debug.h */ + +#ifdef CONFIG_JFS_DEBUG +static int jfs_loglevel_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%d\n", jfsloglevel); + return 0; +} + +static int jfs_loglevel_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, jfs_loglevel_proc_show, NULL); +} + +static ssize_t jfs_loglevel_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *ppos) +{ + char c; + + if (get_user(c, buffer)) + return -EFAULT; + + /* yes, I know this is an ASCIIism. --hch */ + if (c < '0' || c > '9') + return -EINVAL; + jfsloglevel = c - '0'; + return count; +} + +static const struct proc_ops jfs_loglevel_proc_ops = { + .proc_open = jfs_loglevel_proc_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, + .proc_write = jfs_loglevel_proc_write, +}; +#endif + +void jfs_proc_init(void) +{ + struct proc_dir_entry *base; + + base = proc_mkdir("fs/jfs", NULL); + if (!base) + return; + +#ifdef CONFIG_JFS_STATISTICS + proc_create_single("lmstats", 0, base, jfs_lmstats_proc_show); + proc_create_single("txstats", 0, base, jfs_txstats_proc_show); + proc_create_single("xtstat", 0, base, jfs_xtstat_proc_show); + proc_create_single("mpstat", 0, base, jfs_mpstat_proc_show); +#endif +#ifdef CONFIG_JFS_DEBUG + proc_create_single("TxAnchor", 0, base, jfs_txanchor_proc_show); + proc_create("loglevel", 0, base, &jfs_loglevel_proc_ops); +#endif +} + +void jfs_proc_clean(void) +{ + remove_proc_subtree("fs/jfs", NULL); +} + +#endif /* PROC_FS_JFS */ -- cgit v1.3.1