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 --- drivers/dma/idxd/debugfs.c | 138 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 drivers/dma/idxd/debugfs.c (limited to 'drivers/dma/idxd/debugfs.c') diff --git a/drivers/dma/idxd/debugfs.c b/drivers/dma/idxd/debugfs.c new file mode 100644 index 000000000..ad4245cb3 --- /dev/null +++ b/drivers/dma/idxd/debugfs.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2021 Intel Corporation. All rights rsvd. */ +#include +#include +#include +#include +#include +#include +#include +#include "idxd.h" +#include "registers.h" + +static struct dentry *idxd_debugfs_dir; + +static void dump_event_entry(struct idxd_device *idxd, struct seq_file *s, + u16 index, int *count, bool processed) +{ + struct idxd_evl *evl = idxd->evl; + struct dsa_evl_entry *entry; + struct dsa_completion_record *cr; + u64 *raw; + int i; + int evl_strides = evl_ent_size(idxd) / sizeof(u64); + + entry = (struct dsa_evl_entry *)evl->log + index; + + if (!entry->e.desc_valid) + return; + + seq_printf(s, "Event Log entry %d (real index %u) processed: %u\n", + *count, index, processed); + + seq_printf(s, "desc valid %u wq idx valid %u\n" + "batch %u fault rw %u priv %u error 0x%x\n" + "wq idx %u op %#x pasid %u batch idx %u\n" + "fault addr %#llx\n", + entry->e.desc_valid, entry->e.wq_idx_valid, + entry->e.batch, entry->e.fault_rw, entry->e.priv, + entry->e.error, entry->e.wq_idx, entry->e.operation, + entry->e.pasid, entry->e.batch_idx, entry->e.fault_addr); + + cr = &entry->cr; + seq_printf(s, "status %#x result %#x fault_info %#x bytes_completed %u\n" + "fault addr %#llx inv flags %#x\n\n", + cr->status, cr->result, cr->fault_info, cr->bytes_completed, + cr->fault_addr, cr->invalid_flags); + + raw = (u64 *)entry; + + for (i = 0; i < evl_strides; i++) + seq_printf(s, "entry[%d] = %#llx\n", i, raw[i]); + + seq_puts(s, "\n"); + *count += 1; +} + +static int debugfs_evl_show(struct seq_file *s, void *d) +{ + struct idxd_device *idxd = s->private; + struct idxd_evl *evl = idxd->evl; + union evl_status_reg evl_status; + u16 h, t, evl_size, i; + int count = 0; + bool processed = true; + + if (!evl || !evl->log) + return 0; + + mutex_lock(&evl->lock); + + evl_status.bits = ioread64(idxd->reg_base + IDXD_EVLSTATUS_OFFSET); + t = evl_status.tail; + h = evl_status.head; + evl_size = evl->size; + + seq_printf(s, "Event Log head %u tail %u interrupt pending %u\n\n", + evl_status.head, evl_status.tail, evl_status.int_pending); + + i = t; + while (1) { + i = (i + 1) % evl_size; + if (i == t) + break; + + if (processed && i == h) + processed = false; + dump_event_entry(idxd, s, i, &count, processed); + } + + mutex_unlock(&evl->lock); + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(debugfs_evl); + +int idxd_device_init_debugfs(struct idxd_device *idxd) +{ + if (IS_ERR_OR_NULL(idxd_debugfs_dir)) + return 0; + + idxd->dbgfs_dir = debugfs_create_dir(dev_name(idxd_confdev(idxd)), idxd_debugfs_dir); + if (IS_ERR(idxd->dbgfs_dir)) + return PTR_ERR(idxd->dbgfs_dir); + + if (idxd->evl) { + idxd->dbgfs_evl_file = debugfs_create_file("event_log", 0400, + idxd->dbgfs_dir, idxd, + &debugfs_evl_fops); + if (IS_ERR(idxd->dbgfs_evl_file)) { + debugfs_remove_recursive(idxd->dbgfs_dir); + idxd->dbgfs_dir = NULL; + return PTR_ERR(idxd->dbgfs_evl_file); + } + } + + return 0; +} + +void idxd_device_remove_debugfs(struct idxd_device *idxd) +{ + debugfs_remove_recursive(idxd->dbgfs_dir); +} + +int idxd_init_debugfs(void) +{ + if (!debugfs_initialized()) + return 0; + + idxd_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); + if (IS_ERR(idxd_debugfs_dir)) + return PTR_ERR(idxd_debugfs_dir); + return 0; +} + +void idxd_remove_debugfs(void) +{ + debugfs_remove_recursive(idxd_debugfs_dir); +} -- cgit v1.3.1