From 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 2 Sep 2026 15:31:14 -0700 Subject: treewide: refresh kmalloc_obj() conversions This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook --- tools/perf/util/llvm-c-helpers.cpp | 196 +++++++++++++++++++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 tools/perf/util/llvm-c-helpers.cpp (limited to 'tools/perf/util/llvm-c-helpers.cpp') diff --git a/tools/perf/util/llvm-c-helpers.cpp b/tools/perf/util/llvm-c-helpers.cpp new file mode 100644 index 000000000..004081bd1 --- /dev/null +++ b/tools/perf/util/llvm-c-helpers.cpp @@ -0,0 +1,196 @@ +// 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 +#include +#pragma GCC diagnostic pop + +#include +#include +#include +#include +extern "C" { +#include +} +#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 == "") { + /* 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 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 == "") + /* 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 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, "")) + 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 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 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); +} -- cgit v1.3.1