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/gfs2/export.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 194 insertions(+) create mode 100644 fs/gfs2/export.c (limited to 'fs/gfs2/export.c') diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c new file mode 100644 index 000000000..3334c394c --- /dev/null +++ b/fs/gfs2/export.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include + +#include "gfs2.h" +#include "incore.h" +#include "dir.h" +#include "glock.h" +#include "glops.h" +#include "inode.h" +#include "super.h" +#include "rgrp.h" +#include "util.h" + +#define GFS2_SMALL_FH_SIZE 4 +#define GFS2_LARGE_FH_SIZE 8 +#define GFS2_OLD_FH_SIZE 10 + +static int gfs2_encode_fh(struct inode *inode, __u32 *p, int *len, + struct inode *parent) +{ + __be32 *fh = (__force __be32 *)p; + struct super_block *sb = inode->i_sb; + struct gfs2_inode *ip = GFS2_I(inode); + + if (parent && (*len < GFS2_LARGE_FH_SIZE)) { + *len = GFS2_LARGE_FH_SIZE; + return FILEID_INVALID; + } else if (*len < GFS2_SMALL_FH_SIZE) { + *len = GFS2_SMALL_FH_SIZE; + return FILEID_INVALID; + } + + fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32); + fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); + fh[2] = cpu_to_be32(ip->i_no_addr >> 32); + fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); + *len = GFS2_SMALL_FH_SIZE; + + if (!parent || inode == d_inode(sb->s_root)) + return *len; + + ip = GFS2_I(parent); + + fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32); + fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF); + fh[6] = cpu_to_be32(ip->i_no_addr >> 32); + fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF); + *len = GFS2_LARGE_FH_SIZE; + + return *len; +} + +struct get_name_filldir { + struct dir_context ctx; + struct gfs2_inum_host inum; + char *name; +}; + +static bool get_name_filldir(struct dir_context *ctx, const char *name, + int length, loff_t offset, u64 inum, + unsigned int type) +{ + struct get_name_filldir *gnfd = + container_of(ctx, struct get_name_filldir, ctx); + + if (inum != gnfd->inum.no_addr) + return true; + + memcpy(gnfd->name, name, length); + gnfd->name[length] = 0; + + return false; +} + +static int gfs2_get_name(struct dentry *parent, char *name, + struct dentry *child) +{ + struct inode *dir = d_inode(parent); + struct inode *inode = d_inode(child); + struct gfs2_inode *dip, *ip; + struct get_name_filldir gnfd = { + .ctx.actor = get_name_filldir, + .name = name + }; + struct gfs2_holder gh; + int error; + struct file_ra_state f_ra = { .start = 0 }; + + if (!dir) + return -EINVAL; + + if (!S_ISDIR(dir->i_mode) || !inode) + return -EINVAL; + + dip = GFS2_I(dir); + ip = GFS2_I(inode); + + *name = 0; + gnfd.inum.no_addr = ip->i_no_addr; + gnfd.inum.no_formal_ino = ip->i_no_formal_ino; + + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh); + if (error) + return error; + + error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra); + + gfs2_glock_dq_uninit(&gh); + + if (!error && !*name) + error = -ENOENT; + + return error; +} + +static struct dentry *gfs2_get_parent(struct dentry *child) +{ + return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1)); +} + +static struct dentry *gfs2_get_dentry(struct super_block *sb, + struct gfs2_inum_host *inum) +{ + struct gfs2_sbd *sdp = sb->s_fs_info; + struct inode *inode; + + if (!inum->no_formal_ino) + return ERR_PTR(-ESTALE); + inode = gfs2_lookup_by_inum(sdp, inum->no_addr, inum->no_formal_ino, + GFS2_BLKST_DINODE); + return d_obtain_alias(inode); +} + +static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + struct gfs2_inum_host this; + __be32 *fh = (__force __be32 *)fid->raw; + + switch (fh_type) { + case GFS2_SMALL_FH_SIZE: + case GFS2_LARGE_FH_SIZE: + case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_SMALL_FH_SIZE) + return NULL; + this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32; + this.no_formal_ino |= be32_to_cpu(fh[1]); + this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32; + this.no_addr |= be32_to_cpu(fh[3]); + return gfs2_get_dentry(sb, &this); + default: + return NULL; + } +} + +static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + struct gfs2_inum_host parent; + __be32 *fh = (__force __be32 *)fid->raw; + + switch (fh_type) { + case GFS2_LARGE_FH_SIZE: + case GFS2_OLD_FH_SIZE: + if (fh_len < GFS2_LARGE_FH_SIZE) + return NULL; + parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32; + parent.no_formal_ino |= be32_to_cpu(fh[5]); + parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32; + parent.no_addr |= be32_to_cpu(fh[7]); + return gfs2_get_dentry(sb, &parent); + default: + return NULL; + } +} + +const struct export_operations gfs2_export_ops = { + .encode_fh = gfs2_encode_fh, + .fh_to_dentry = gfs2_fh_to_dentry, + .fh_to_parent = gfs2_fh_to_parent, + .get_name = gfs2_get_name, + .get_parent = gfs2_get_parent, +}; + -- cgit v1.3.1