mirror of
https://src.fedoraproject.org/rpms/llvm.git
synced 2024-11-24 09:32:42 +00:00
680f925c31
Resolves: rhbz#2322754 Ref: https://github.com/llvm/llvm-project/issues/114605 Ref: https://github.com/llvm/llvm-project/pull/114907
86 lines
3.7 KiB
Diff
86 lines
3.7 KiB
Diff
From ccc2b792e57d632bc887b226a4e7f0a8189eab8b Mon Sep 17 00:00:00 2001
|
|
From: Josh Stone <jistone@redhat.com>
|
|
Date: Mon, 4 Nov 2024 16:37:49 -0800
|
|
Subject: [PATCH] [profile] Use base+vaddr for `__llvm_write_binary_ids` note
|
|
pointers
|
|
|
|
This function is always examining its own ELF headers in memory, but it
|
|
was trying to use conditions between examining files or memory, and it
|
|
wasn't accounting for LOAD offsets at runtime. This is especially bad if
|
|
a loaded segment has additional padding that's not in the file offsets.
|
|
|
|
Now we do a first scan of the program headers to figure out the runtime
|
|
base address based on `PT_PHDR` and/or `PT_DYNAMIC` (else assume zero),
|
|
similar to libc's `do_start`. Then each `PT_NOTE` pointer is simply the
|
|
base plus the segments's `pt_vaddr`, which includes LOAD offsets.
|
|
|
|
Fixes #114605
|
|
---
|
|
.../lib/profile/InstrProfilingPlatformLinux.c | 40 ++++++++-----------
|
|
1 file changed, 16 insertions(+), 24 deletions(-)
|
|
|
|
diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
|
|
index e2c06d51e0c6..c365129a0768 100644
|
|
--- a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
|
|
+++ b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
|
|
@@ -194,41 +194,33 @@ static int WriteBinaryIds(ProfDataWriter *Writer, const ElfW(Nhdr) * Note,
|
|
*/
|
|
COMPILER_RT_VISIBILITY int __llvm_write_binary_ids(ProfDataWriter *Writer) {
|
|
extern const ElfW(Ehdr) __ehdr_start __attribute__((visibility("hidden")));
|
|
+ extern ElfW(Dyn) _DYNAMIC[] __attribute__((weak, visibility("hidden")));
|
|
+
|
|
const ElfW(Ehdr) *ElfHeader = &__ehdr_start;
|
|
const ElfW(Phdr) *ProgramHeader =
|
|
(const ElfW(Phdr) *)((uintptr_t)ElfHeader + ElfHeader->e_phoff);
|
|
|
|
+ /* Compute the added base address in case of position-independent code. */
|
|
+ uintptr_t Base = 0;
|
|
+ for (uint32_t I = 0; I < ElfHeader->e_phnum; I++) {
|
|
+ if (ProgramHeader[I].p_type == PT_PHDR)
|
|
+ Base = (uintptr_t)ProgramHeader - ProgramHeader[I].p_vaddr;
|
|
+ if (ProgramHeader[I].p_type == PT_DYNAMIC && _DYNAMIC)
|
|
+ Base = (uintptr_t)_DYNAMIC - ProgramHeader[I].p_vaddr;
|
|
+ }
|
|
+
|
|
int TotalBinaryIdsSize = 0;
|
|
- uint32_t I;
|
|
/* Iterate through entries in the program header. */
|
|
- for (I = 0; I < ElfHeader->e_phnum; I++) {
|
|
+ for (uint32_t I = 0; I < ElfHeader->e_phnum; I++) {
|
|
/* Look for the notes segment in program header entries. */
|
|
if (ProgramHeader[I].p_type != PT_NOTE)
|
|
continue;
|
|
|
|
/* There can be multiple notes segment, and examine each of them. */
|
|
- const ElfW(Nhdr) * Note;
|
|
- const ElfW(Nhdr) * NotesEnd;
|
|
- /*
|
|
- * When examining notes in file, use p_offset, which is the offset within
|
|
- * the elf file, to find the start of notes.
|
|
- */
|
|
- if (ProgramHeader[I].p_memsz == 0 ||
|
|
- ProgramHeader[I].p_memsz == ProgramHeader[I].p_filesz) {
|
|
- Note = (const ElfW(Nhdr) *)((uintptr_t)ElfHeader +
|
|
- ProgramHeader[I].p_offset);
|
|
- NotesEnd = (const ElfW(Nhdr) *)((const char *)(Note) +
|
|
- ProgramHeader[I].p_filesz);
|
|
- } else {
|
|
- /*
|
|
- * When examining notes in memory, use p_vaddr, which is the address of
|
|
- * section after loaded to memory, to find the start of notes.
|
|
- */
|
|
- Note =
|
|
- (const ElfW(Nhdr) *)((uintptr_t)ElfHeader + ProgramHeader[I].p_vaddr);
|
|
- NotesEnd =
|
|
- (const ElfW(Nhdr) *)((const char *)(Note) + ProgramHeader[I].p_memsz);
|
|
- }
|
|
+ const ElfW(Nhdr) *Note =
|
|
+ (const ElfW(Nhdr) *)(Base + ProgramHeader[I].p_vaddr);
|
|
+ const ElfW(Nhdr) *NotesEnd =
|
|
+ (const ElfW(Nhdr) *)((const char *)(Note) + ProgramHeader[I].p_memsz);
|
|
|
|
int BinaryIdsSize = WriteBinaryIds(Writer, Note, NotesEnd);
|
|
if (TotalBinaryIdsSize == -1)
|
|
--
|
|
2.47.0
|
|
|