// SPDX-License-Identifier: GPL-2.0
/*
* Must come before the linux/compiler.h include, which defines several
* macros (e.g. noinline) that conflict with compiler builtins used
* by LLVM.
*/
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter" /* Needed for LLVM <= 15 */
#include <llvm/DebugInfo/Symbolize/Symbolize.h>
#include <llvm/Support/TargetSelect.h>
#pragma GCC diagnostic pop
#include <inttypes.h>
#include <stdio.h>
#include <sys/types.h>
#include <linux/compiler.h>
extern "C" {
#include <linux/zalloc.h>
}
#include "symbol_conf.h"
#include "llvm-c-helpers.h"
extern "C"
char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name);
using namespace llvm;
using llvm::symbolize::LLVMSymbolizer;
/*
* Allocate a static LLVMSymbolizer, which will live to the end of the program.
* Unlike the bfd paths, LLVMSymbolizer has its own cache, so we do not need
* to store anything in the dso struct.
*/
static LLVMSymbolizer *get_symbolizer()
{
static LLVMSymbolizer *instance = nullptr;
if (instance == nullptr) {
LLVMSymbolizer::Options opts;
/*
* LLVM sometimes demangles slightly different from the rest
* of the code, and this mismatch can cause new_inline_sym()
* to get confused and mark non-inline symbol as inlined
* (since the name does not properly match up with base_sym).
* Thus, disable the demangling and let the rest of the code
* handle it.
*/
opts.Demangle = false;
instance = new LLVMSymbolizer(opts);
}
return instance;
}
/* Returns 0 on error, 1 on success. */
static int extract_file_and_line(const DILineInfo &line_info, char **file,
unsigned int *line)
{
if (file) {
if (line_info.FileName == "<invalid>") {
/* Match the convention of libbfd. */
*file = nullptr;
} else {
/* The caller expects to get something it can free(). */
*file = strdup(line_info.FileName.c_str());
if (*file == nullptr)
return 0;
}
}
if (line)
*line = line_info.Line;
return 1;
}
extern "C"
int llvm_addr2line(const char *dso_name, u64 addr,
char **file, unsigned int *line,
bool unwind_inlines,
llvm_a2l_frame **inline_frames)
{
LLVMSymbolizer *symbolizer = get_symbolizer();
object::SectionedAddress sectioned_addr = {
addr,
object::SectionedAddress::UndefSection
};
if (unwind_inlines) {
Expected<DIInliningInfo> res_or_err =
symbolizer->symbolizeInlinedCode(dso_name,
sectioned_addr);
if (!res_or_err)
return 0;
unsigned num_frames = res_or_err->getNumberOfFrames();
if (num_frames == 0)
return 0;
if (extract_file_and_line(res_or_err->getFrame(0),
file, line) == 0)
return 0;
*inline_frames = (llvm_a2l_frame *)calloc(
num_frames, sizeof(**inline_frames));
if (*inline_frames == nullptr)
return 0;
for (unsigned i = 0; i < num_frames; ++i) {
const DILineInfo &src = res_or_err->getFrame(i);
llvm_a2l_frame &dst = (*inline_frames)[i];
if (src.FileName == "<invalid>")
/* Match the convention of libbfd. */
dst.filename = nullptr;
else
dst.filename = strdup(src.FileName.c_str());
dst.funcname = strdup(src.FunctionName.c_str());
dst.line = src.Line;
if (dst.filename == nullptr ||
dst.funcname == nullptr) {
for (unsigned j = 0; j <= i; ++j) {
zfree(&(*inline_frames)[j].filename);
zfree(&(*inline_frames)[j].funcname);
}
zfree(inline_frames);
return 0;
}
}
return num_frames;
} else {
if (inline_frames)
*inline_frames = nullptr;
Expected<DILineInfo> res_or_err =
symbolizer->symbolizeCode(dso_name, sectioned_addr);
if (!res_or_err)
return 0;
return extract_file_and_line(*res_or_err, file, line);
}
}
static char *
make_symbol_relative_string(struct dso *dso, const char *sym_name,
u64 addr, u64 base_addr)
{
if (!strcmp(sym_name, "<invalid>"))
return NULL;
char *demangled = dso__demangle_sym(dso, 0, sym_name);
if (base_addr && base_addr != addr) {
char buf[256];
snprintf(buf, sizeof(buf), "%s+0x%" PRIx64,
demangled ? demangled : sym_name, addr - base_addr);
free(demangled);
return strdup(buf);
} else {
if (demangled)
return demangled;
else
return strdup(sym_name);
}
}
extern "C"
char *llvm_name_for_code(struct dso *dso, const char *dso_name, u64 addr)
{
LLVMSymbolizer *symbolizer = get_symbolizer();
object::SectionedAddress sectioned_addr = {
addr,
object::SectionedAddress::UndefSection
};
Expected<DILineInfo> res_or_err =
symbolizer->symbolizeCode(dso_name, sectioned_addr);
if (!res_or_err) {
return NULL;
}
return make_symbol_relative_string(
dso, res_or_err->FunctionName.c_str(),
addr, res_or_err->StartAddress ? *res_or_err->StartAddress : 0);
}
extern "C"
char *llvm_name_for_data(struct dso *dso, const char *dso_name, u64 addr)
{
LLVMSymbolizer *symbolizer = get_symbolizer();
object::SectionedAddress sectioned_addr = {
addr,
object::SectionedAddress::UndefSection
};
Expected<DIGlobal> res_or_err =
symbolizer->symbolizeData(dso_name, sectioned_addr);
if (!res_or_err) {
return NULL;
}
return make_symbol_relative_string(
dso, res_or_err->Name.c_str(),
addr, res_or_err->Start);
}