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 --- tools/perf/util/trace-event-parse.c | 323 ++++++++++++++++++++++++++++++++++++ 1 file changed, 323 insertions(+) create mode 100644 tools/perf/util/trace-event-parse.c (limited to 'tools/perf/util/trace-event-parse.c') diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c new file mode 100644 index 000000000..9c015fc2b --- /dev/null +++ b/tools/perf/util/trace-event-parse.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2009, Steven Rostedt + */ +#include +#include +#include +#include + +#include "debug.h" +#include "trace-event.h" + +#include +#include +#include + +static int get_common_field(struct scripting_context *context, + int *offset, int *size, const char *type) +{ + struct tep_handle *pevent = context->pevent; + struct tep_event *event; + struct tep_format_field *field; + + if (!*size) { + + event = tep_get_first_event(pevent); + if (!event) + return 0; + + field = tep_find_common_field(event, type); + if (!field) + return 0; + *offset = field->offset; + *size = field->size; + } + + return tep_read_number(pevent, context->event_data + *offset, *size); +} + +int common_lock_depth(struct scripting_context *context) +{ + static int offset; + static int size; + int ret; + + ret = get_common_field(context, &size, &offset, + "common_lock_depth"); + if (ret < 0) + return -1; + + return ret; +} + +int common_flags(struct scripting_context *context) +{ + static int offset; + static int size; + int ret; + + ret = get_common_field(context, &size, &offset, + "common_flags"); + if (ret < 0) + return -1; + + return ret; +} + +int common_pc(struct scripting_context *context) +{ + static int offset; + static int size; + int ret; + + ret = get_common_field(context, &size, &offset, + "common_preempt_count"); + if (ret < 0) + return -1; + + return ret; +} + +unsigned long long +raw_field_value(struct tep_event *event, const char *name, void *data) +{ + struct tep_format_field *field; + unsigned long long val; + + field = tep_find_any_field(event, name); + if (!field) + return 0ULL; + + tep_read_number_field(field, data, &val); + + return val; +} + +unsigned long long read_size(struct tep_event *event, void *ptr, int size) +{ + return tep_read_number(event->tep, ptr, size); +} + +void event_format__fprintf(const struct tep_event *event, + int cpu, void *data, int size, FILE *fp) +{ + struct tep_record record; + struct trace_seq s; + + memset(&record, 0, sizeof(record)); + record.cpu = cpu; + record.size = size; + record.data = data; + + trace_seq_init(&s); + tep_print_event(event->tep, &s, &record, "%s", TEP_PRINT_INFO); + trace_seq_do_fprintf(&s, fp); + trace_seq_destroy(&s); +} + +/* + * prev_state is of size long, which is 32 bits on 32 bit architectures. + * As it needs to have the same bits for both 32 bit and 64 bit architectures + * we can just assume that the flags we care about will all be within + * the 32 bits. + */ +#define MAX_STATE_BITS 32 + +static const char *convert_sym(struct tep_print_flag_sym *sym) +{ + static char save_states[MAX_STATE_BITS + 1]; + + memset(save_states, 0, sizeof(save_states)); + + /* This is the flags for the prev_state_field, now make them into a string */ + for (; sym; sym = sym->next) { + long bitmask = strtoul(sym->value, NULL, 0); + int i; + + for (i = 0; !(bitmask & 1); i++) + bitmask >>= 1; + + if (i >= MAX_STATE_BITS) + continue; + + save_states[i] = sym->str[0]; + } + + return save_states; +} + +static struct tep_print_arg_field * +find_arg_field(struct tep_format_field *prev_state_field, struct tep_print_arg *arg) +{ + struct tep_print_arg_field *field; + + if (!arg) + return NULL; + + if (arg->type == TEP_PRINT_FIELD) + return &arg->field; + + if (arg->type == TEP_PRINT_OP) { + field = find_arg_field(prev_state_field, arg->op.left); + if (field && field->field == prev_state_field) + return field; + field = find_arg_field(prev_state_field, arg->op.right); + if (field && field->field == prev_state_field) + return field; + } + return NULL; +} + +static struct tep_print_flag_sym * +test_flags(struct tep_format_field *prev_state_field, struct tep_print_arg *arg) +{ + struct tep_print_arg_field *field; + + field = find_arg_field(prev_state_field, arg->flags.field); + if (!field) + return NULL; + + return arg->flags.flags; +} + +static struct tep_print_flag_sym * +search_op(struct tep_format_field *prev_state_field, struct tep_print_arg *arg) +{ + struct tep_print_flag_sym *sym = NULL; + + if (!arg) + return NULL; + + if (arg->type == TEP_PRINT_OP) { + sym = search_op(prev_state_field, arg->op.left); + if (sym) + return sym; + + sym = search_op(prev_state_field, arg->op.right); + if (sym) + return sym; + } else if (arg->type == TEP_PRINT_FLAGS) { + sym = test_flags(prev_state_field, arg); + } + + return sym; +} + +const char *parse_task_states(struct tep_format_field *state_field) +{ + struct tep_print_flag_sym *sym; + struct tep_print_arg *arg; + struct tep_event *event; + + event = state_field->event; + + /* + * Look at the event format fields, and search for where + * the prev_state is parsed via the format flags. + */ + for (arg = event->print_fmt.args; arg; arg = arg->next) { + /* + * Currently, the __print_flags() for the prev_state + * is embedded in operations, so they too must be + * searched. + */ + sym = search_op(state_field, arg); + if (sym) + return convert_sym(sym); + } + return NULL; +} + +void parse_ftrace_printk(struct tep_handle *pevent, + char *file, unsigned int size __maybe_unused) +{ + unsigned long long addr; + char *printk; + char *line; + char *next = NULL; + char *addr_str; + char *fmt = NULL; + + line = strtok_r(file, "\n", &next); + while (line) { + addr_str = strtok_r(line, ":", &fmt); + if (!addr_str) { + pr_warning("printk format with empty entry"); + break; + } + addr = strtoull(addr_str, NULL, 16); + /* fmt still has a space, skip it */ + printk = strdup(fmt+1); + line = strtok_r(NULL, "\n", &next); + tep_register_print_string(pevent, printk, addr); + free(printk); + } +} + +void parse_saved_cmdline(struct tep_handle *pevent, + char *file, unsigned int size __maybe_unused) +{ + char comm[17]; /* Max comm length in the kernel is 16. */ + char *line; + char *next = NULL; + int pid; + + line = strtok_r(file, "\n", &next); + while (line) { + if (sscanf(line, "%d %16s", &pid, comm) == 2) + tep_register_comm(pevent, comm, pid); + line = strtok_r(NULL, "\n", &next); + } +} + +int parse_ftrace_file(struct tep_handle *pevent, char *buf, unsigned long size) +{ + return tep_parse_event(pevent, buf, size, "ftrace"); +} + +int parse_event_file(struct tep_handle *pevent, + char *buf, unsigned long size, char *sys) +{ + return tep_parse_event(pevent, buf, size, sys); +} + +struct flag { + const char *name; + unsigned long long value; +}; + +static const struct flag flags[] = { + { "HI_SOFTIRQ", 0 }, + { "TIMER_SOFTIRQ", 1 }, + { "NET_TX_SOFTIRQ", 2 }, + { "NET_RX_SOFTIRQ", 3 }, + { "BLOCK_SOFTIRQ", 4 }, + { "IRQ_POLL_SOFTIRQ", 5 }, + { "TASKLET_SOFTIRQ", 6 }, + { "SCHED_SOFTIRQ", 7 }, + { "HRTIMER_SOFTIRQ", 8 }, + { "RCU_SOFTIRQ", 9 }, + + { "HRTIMER_NORESTART", 0 }, + { "HRTIMER_RESTART", 1 }, +}; + +unsigned long long eval_flag(const char *flag) +{ + int i; + + /* + * Some flags in the format files do not get converted. + * If the flag is not numeric, see if it is something that + * we already know about. + */ + if (isdigit(flag[0])) + return strtoull(flag, NULL, 0); + + for (i = 0; i < (int)(ARRAY_SIZE(flags)); i++) + if (strcmp(flags[i].name, flag) == 0) + return flags[i].value; + + return 0; +} -- cgit v1.3.1