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/ufs/util.c | 223 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 223 insertions(+) create mode 100644 fs/ufs/util.c (limited to 'fs/ufs/util.c') diff --git a/fs/ufs/util.c b/fs/ufs/util.c new file mode 100644 index 000000000..dff6f7461 --- /dev/null +++ b/fs/ufs/util.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ufs/util.c + * + * Copyright (C) 1998 + * Daniel Pirkl + * Charles University, Faculty of Mathematics and Physics + */ + +#include +#include +#include + +#include "ufs_fs.h" +#include "ufs.h" +#include "swab.h" +#include "util.h" + +struct ufs_buffer_head * _ubh_bread_ (struct ufs_sb_private_info * uspi, + struct super_block *sb, u64 fragment, u64 size) +{ + struct ufs_buffer_head * ubh; + unsigned i, j ; + u64 count = 0; + if (size & ~uspi->s_fmask) + return NULL; + count = size >> uspi->s_fshift; + if (count > UFS_MAXFRAG) + return NULL; + ubh = kmalloc_obj(struct ufs_buffer_head, GFP_NOFS); + if (!ubh) + return NULL; + ubh->fragment = fragment; + ubh->count = count; + for (i = 0; i < count; i++) + if (!(ubh->bh[i] = sb_bread(sb, fragment + i))) + goto failed; + for (; i < UFS_MAXFRAG; i++) + ubh->bh[i] = NULL; + return ubh; +failed: + for (j = 0; j < i; j++) + brelse (ubh->bh[j]); + kfree(ubh); + return NULL; +} + +struct ufs_buffer_head * ubh_bread_uspi (struct ufs_sb_private_info * uspi, + struct super_block *sb, u64 fragment, u64 size) +{ + unsigned i, j; + u64 count = 0; + if (size & ~uspi->s_fmask) + return NULL; + count = size >> uspi->s_fshift; + if (count <= 0 || count > UFS_MAXFRAG) + return NULL; + USPI_UBH(uspi)->fragment = fragment; + USPI_UBH(uspi)->count = count; + for (i = 0; i < count; i++) + if (!(USPI_UBH(uspi)->bh[i] = sb_bread(sb, fragment + i))) + goto failed; + for (; i < UFS_MAXFRAG; i++) + USPI_UBH(uspi)->bh[i] = NULL; + return USPI_UBH(uspi); +failed: + for (j = 0; j < i; j++) + brelse (USPI_UBH(uspi)->bh[j]); + return NULL; +} + +void ubh_brelse (struct ufs_buffer_head * ubh) +{ + unsigned i; + if (!ubh) + return; + for (i = 0; i < ubh->count; i++) + brelse (ubh->bh[i]); + kfree (ubh); +} + +void ubh_brelse_uspi (struct ufs_sb_private_info * uspi) +{ + unsigned i; + if (!USPI_UBH(uspi)) + return; + for ( i = 0; i < USPI_UBH(uspi)->count; i++ ) { + brelse (USPI_UBH(uspi)->bh[i]); + USPI_UBH(uspi)->bh[i] = NULL; + } +} + +void ubh_mark_buffer_dirty (struct ufs_buffer_head * ubh) +{ + unsigned i; + if (!ubh) + return; + for ( i = 0; i < ubh->count; i++ ) + mark_buffer_dirty (ubh->bh[i]); +} + +void ubh_sync_block(struct ufs_buffer_head *ubh) +{ + if (ubh) { + unsigned i; + + for (i = 0; i < ubh->count; i++) + write_dirty_buffer(ubh->bh[i], 0); + + for (i = 0; i < ubh->count; i++) + wait_on_buffer(ubh->bh[i]); + } +} + +void ubh_bforget (struct ufs_buffer_head * ubh) +{ + unsigned i; + if (!ubh) + return; + for ( i = 0; i < ubh->count; i++ ) if ( ubh->bh[i] ) + bforget (ubh->bh[i]); +} + +int ubh_buffer_dirty (struct ufs_buffer_head * ubh) +{ + unsigned i; + unsigned result = 0; + if (!ubh) + return 0; + for ( i = 0; i < ubh->count; i++ ) + result |= buffer_dirty(ubh->bh[i]); + return result; +} + +dev_t +ufs_get_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi) +{ + __u32 fs32; + dev_t dev; + + if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86) + fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[1]); + else + fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[0]); + switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) { + case UFS_ST_SUNx86: + case UFS_ST_SUN: + if ((fs32 & 0xffff0000) == 0 || + (fs32 & 0xffff0000) == 0xffff0000) + dev = old_decode_dev(fs32 & 0x7fff); + else + dev = MKDEV(sysv_major(fs32), sysv_minor(fs32)); + break; + + default: + dev = old_decode_dev(fs32); + break; + } + return dev; +} + +void +ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev) +{ + __u32 fs32; + + switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) { + case UFS_ST_SUNx86: + case UFS_ST_SUN: + fs32 = sysv_encode_dev(dev); + if ((fs32 & 0xffff8000) == 0) { + fs32 = old_encode_dev(dev); + } + break; + + default: + fs32 = old_encode_dev(dev); + break; + } + if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86) + ufsi->i_u1.i_data[1] = cpu_to_fs32(sb, fs32); + else + ufsi->i_u1.i_data[0] = cpu_to_fs32(sb, fs32); +} + +/** + * ufs_get_locked_folio() - locate, pin and lock a pagecache folio, if not exist + * read it from disk. + * @mapping: the address_space to search + * @index: the page index + * + * Locates the desired pagecache folio, if not exist we'll read it, + * locks it, increments its reference + * count and returns its address. + * + */ +struct folio *ufs_get_locked_folio(struct address_space *mapping, + pgoff_t index) +{ + struct inode *inode = mapping->host; + struct folio *folio = filemap_lock_folio(mapping, index); + if (IS_ERR(folio)) { + folio = read_mapping_folio(mapping, index, NULL); + + if (IS_ERR(folio)) { + printk(KERN_ERR "ufs_change_blocknr: read_mapping_folio error: ino %llu, index: %lu\n", + mapping->host->i_ino, index); + return folio; + } + + folio_lock(folio); + + if (unlikely(folio->mapping == NULL)) { + /* Truncate got there first */ + folio_unlock(folio); + folio_put(folio); + return NULL; + } + } + if (!folio_buffers(folio)) + create_empty_buffers(folio, 1 << inode->i_blkbits, 0); + return folio; +} -- cgit v1.3.1