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/hfsplus/ioctl.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 fs/hfsplus/ioctl.c (limited to 'fs/hfsplus/ioctl.c') diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c new file mode 100644 index 000000000..40d04dba1 --- /dev/null +++ b/fs/hfsplus/ioctl.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/hfsplus/ioctl.c + * + * Copyright (C) 2003 + * Ethan Benson + * partially derived from linux/fs/ext2/ioctl.c + * Copyright (C) 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * hfsplus ioctls + */ + +#include +#include +#include +#include +#include +#include "hfsplus_fs.h" + +/* + * "Blessing" an HFS+ filesystem writes metadata to the superblock informing + * the platform firmware which file to boot from + */ +static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags) +{ + struct dentry *dentry = file->f_path.dentry; + struct inode *inode = d_inode(dentry); + struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb); + struct hfsplus_vh *vh = sbi->s_vhdr; + struct hfsplus_vh *bvh = sbi->s_backup_vhdr; + u32 cnid = (unsigned long)dentry->d_fsdata; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + mutex_lock(&sbi->vh_mutex); + + /* Directory containing the bootable system */ + vh->finder_info[0] = bvh->finder_info[0] = + cpu_to_be32(d_parent_ino(dentry)); + + /* + * Bootloader. Just using the inode here breaks in the case of + * hard links - the firmware wants the ID of the hard link file, + * but the inode points at the indirect inode + */ + vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid); + + /* Per spec, the OS X system folder - same as finder_info[0] here */ + vh->finder_info[5] = bvh->finder_info[5] = + cpu_to_be32(d_parent_ino(dentry)); + + mutex_unlock(&sbi->vh_mutex); + return 0; +} + +long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + + switch (cmd) { + case HFSPLUS_IOC_BLESS: + return hfsplus_ioctl_bless(file, argp); + default: + return -ENOTTY; + } +} -- cgit v1.3.1