Files
clang-p2996/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
Gulfem Savrun Yeniceri 6c0e6f91d7 [profile] Add static keyword to binary id functions
This patch adds static keyword to internal functions that write
binary id to restrict visibility to the file that they are declared.

Differential Revision: https://reviews.llvm.org/D108154
2021-08-16 19:36:47 +00:00

204 lines
7.2 KiB
C

/*===- InstrProfilingPlatformLinux.c - Profile data Linux platform ------===*\
|*
|* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|* See https://llvm.org/LICENSE.txt for license information.
|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|*
\*===----------------------------------------------------------------------===*/
#if defined(__linux__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \
(defined(__sun__) && defined(__svr4__)) || defined(__NetBSD__)
#include <elf.h>
#include <link.h>
#include <stdlib.h>
#include <string.h>
#include "InstrProfiling.h"
#include "InstrProfilingInternal.h"
#if defined(__FreeBSD__) && !defined(ElfW)
/*
* FreeBSD's elf.h and link.h headers do not define the ElfW(type) macro yet.
* If this is added to all supported FreeBSD versions in the future, this
* compatibility macro can be removed.
*/
#define ElfW(type) __ElfN(type)
#endif
#define PROF_DATA_START INSTR_PROF_SECT_START(INSTR_PROF_DATA_COMMON)
#define PROF_DATA_STOP INSTR_PROF_SECT_STOP(INSTR_PROF_DATA_COMMON)
#define PROF_NAME_START INSTR_PROF_SECT_START(INSTR_PROF_NAME_COMMON)
#define PROF_NAME_STOP INSTR_PROF_SECT_STOP(INSTR_PROF_NAME_COMMON)
#define PROF_CNTS_START INSTR_PROF_SECT_START(INSTR_PROF_CNTS_COMMON)
#define PROF_CNTS_STOP INSTR_PROF_SECT_STOP(INSTR_PROF_CNTS_COMMON)
#define PROF_ORDERFILE_START INSTR_PROF_SECT_START(INSTR_PROF_ORDERFILE_COMMON)
#define PROF_VNODES_START INSTR_PROF_SECT_START(INSTR_PROF_VNODES_COMMON)
#define PROF_VNODES_STOP INSTR_PROF_SECT_STOP(INSTR_PROF_VNODES_COMMON)
/* Declare section start and stop symbols for various sections
* generated by compiler instrumentation.
*/
extern __llvm_profile_data PROF_DATA_START COMPILER_RT_VISIBILITY
COMPILER_RT_WEAK;
extern __llvm_profile_data PROF_DATA_STOP COMPILER_RT_VISIBILITY
COMPILER_RT_WEAK;
extern uint64_t PROF_CNTS_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern uint64_t PROF_CNTS_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern uint32_t PROF_ORDERFILE_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern char PROF_NAME_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern char PROF_NAME_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern ValueProfNode PROF_VNODES_START COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
extern ValueProfNode PROF_VNODES_STOP COMPILER_RT_VISIBILITY COMPILER_RT_WEAK;
COMPILER_RT_VISIBILITY const __llvm_profile_data *
__llvm_profile_begin_data(void) {
return &PROF_DATA_START;
}
COMPILER_RT_VISIBILITY const __llvm_profile_data *
__llvm_profile_end_data(void) {
return &PROF_DATA_STOP;
}
COMPILER_RT_VISIBILITY const char *__llvm_profile_begin_names(void) {
return &PROF_NAME_START;
}
COMPILER_RT_VISIBILITY const char *__llvm_profile_end_names(void) {
return &PROF_NAME_STOP;
}
COMPILER_RT_VISIBILITY uint64_t *__llvm_profile_begin_counters(void) {
return &PROF_CNTS_START;
}
COMPILER_RT_VISIBILITY uint64_t *__llvm_profile_end_counters(void) {
return &PROF_CNTS_STOP;
}
COMPILER_RT_VISIBILITY uint32_t *__llvm_profile_begin_orderfile(void) {
return &PROF_ORDERFILE_START;
}
COMPILER_RT_VISIBILITY ValueProfNode *
__llvm_profile_begin_vnodes(void) {
return &PROF_VNODES_START;
}
COMPILER_RT_VISIBILITY ValueProfNode *__llvm_profile_end_vnodes(void) {
return &PROF_VNODES_STOP;
}
COMPILER_RT_VISIBILITY ValueProfNode *CurrentVNode = &PROF_VNODES_START;
COMPILER_RT_VISIBILITY ValueProfNode *EndVNode = &PROF_VNODES_STOP;
#ifdef NT_GNU_BUILD_ID
static size_t RoundUp(size_t size, size_t align) {
return (size + align - 1) & ~(align - 1);
}
/*
* Write binary id length and then its data, because binary id does not
* have a fixed length.
*/
static int WriteOneBinaryId(ProfDataWriter *Writer, uint64_t BinaryIdLen,
const uint8_t *BinaryIdData) {
ProfDataIOVec BinaryIdIOVec[] = {
{&BinaryIdLen, sizeof(uint64_t), 1, 0},
{BinaryIdData, sizeof(uint8_t), BinaryIdLen, 0}};
if (Writer->Write(Writer, BinaryIdIOVec,
sizeof(BinaryIdIOVec) / sizeof(*BinaryIdIOVec)))
return -1;
/* Successfully wrote binary id, report success. */
return 0;
}
/*
* Look for the note that has the name "GNU\0" and type NT_GNU_BUILD_ID
* that contains build id. If build id exists, write binary id.
*
* Each note in notes section starts with a struct which includes
* n_namesz, n_descsz, and n_type members. It is followed by the name
* (whose length is defined in n_namesz) and then by the descriptor
* (whose length is defined in n_descsz).
*
* Note sections like .note.ABI-tag and .note.gnu.build-id are aligned
* to 4 bytes, so round n_namesz and n_descsz to the nearest 4 bytes.
*/
static int WriteBinaryIdForNote(ProfDataWriter *Writer,
const ElfW(Nhdr) * Note) {
int BinaryIdSize = 0;
const char *NoteName = (const char *)Note + sizeof(ElfW(Nhdr));
if (Note->n_type == NT_GNU_BUILD_ID && Note->n_namesz == 4 &&
memcmp(NoteName, "GNU\0", 4) == 0) {
uint64_t BinaryIdLen = Note->n_descsz;
const uint8_t *BinaryIdData =
(const uint8_t *)(NoteName + RoundUp(Note->n_namesz, 4));
if (Writer != NULL &&
WriteOneBinaryId(Writer, BinaryIdLen, BinaryIdData) == -1)
return -1;
BinaryIdSize = sizeof(BinaryIdLen) + BinaryIdLen;
}
return BinaryIdSize;
}
/*
* Helper function that iterates through notes section and find build ids.
* If writer is given, write binary ids into profiles.
* If an error happens while writing, return -1.
*/
static int WriteBinaryIds(ProfDataWriter *Writer, const ElfW(Nhdr) * Note,
const ElfW(Nhdr) * NotesEnd) {
int TotalBinaryIdsSize = 0;
while (Note < NotesEnd) {
int Result = WriteBinaryIdForNote(Writer, Note);
if (Result == -1)
return -1;
TotalBinaryIdsSize += Result;
/* Calculate the offset of the next note in notes section. */
size_t NoteOffset = sizeof(ElfW(Nhdr)) + RoundUp(Note->n_namesz, 4) +
RoundUp(Note->n_descsz, 4);
Note = (const ElfW(Nhdr) *)((const char *)(Note) + NoteOffset);
}
return TotalBinaryIdsSize;
}
/*
* Write binary ids into profiles if writer is given.
* Return the total size of binary ids.
* If an error happens while writing, return -1.
*/
COMPILER_RT_VISIBILITY int __llvm_write_binary_ids(ProfDataWriter *Writer) {
extern const ElfW(Ehdr) __ehdr_start __attribute__((visibility("hidden")));
const ElfW(Ehdr) *ElfHeader = &__ehdr_start;
const ElfW(Phdr) *ProgramHeader =
(const ElfW(Phdr) *)((uintptr_t)ElfHeader + ElfHeader->e_phoff);
uint32_t I;
/* Iterate through entries in the program header. */
for (I = 0; I < ElfHeader->e_phnum; I++) {
/* Look for the notes section in program header entries. */
if (ProgramHeader[I].p_type != PT_NOTE)
continue;
const ElfW(Nhdr) *Note =
(const ElfW(Nhdr) *)((uintptr_t)ElfHeader + ProgramHeader[I].p_offset);
const ElfW(Nhdr) *NotesEnd =
(const ElfW(Nhdr) *)((const char *)(Note) + ProgramHeader[I].p_filesz);
return WriteBinaryIds(Writer, Note, NotesEnd);
}
return 0;
}
#else /* !NT_GNU_BUILD_ID */
/*
* Fallback implementation for targets that don't support the GNU
* extensions NT_GNU_BUILD_ID and __ehdr_start.
*/
COMPILER_RT_VISIBILITY int __llvm_write_binary_ids(ProfDataWriter *Writer) {
return 0;
}
#endif
#endif