https://github.com/llvmbot created
https://github.com/llvm/llvm-project/pull/131398
Backport 8413f4d837a96458104f63bab72c751b8285a458
Requested by: @nikic
>From cb50aaf8a11b89f2785641fba5ffd4b67f566a32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Rodr=C3=ADguez=20Troiti=C3=B1o?=
<drodrig...@users.noreply.github.com>
Date: Fri, 14 Mar 2025 13:43:48 -0700
Subject: [PATCH] [llvm-objcopy] Apply encryptable offset to first segment, not
section (#130517)
Bug introduced #120995. The LLD code calculates the "size" of the Mach-O
headers, and then uses that size to place the segments, but the `__TEXT`
section stays at `fileoff` zero. When I wrote the code into llvm-objcopy
I calculated the extra space into the initial offset, which moved all
the sections back 1 page.
Besides the modified test checking for the right `fileoff` values of the
sections and the segments, I also manually checked the generated
binaries after `llvm-objcopy` using `dyld_info`, as the bug report
suggested.
Fixes #130472
(cherry picked from commit 8413f4d837a96458104f63bab72c751b8285a458)
---
llvm/lib/ObjCopy/MachO/MachOLayoutBuilder.cpp | 13 ++++++++-----
.../MachO/strip-with-encryption-info.test | 12 +++++++++---
2 files changed, 17 insertions(+), 8 deletions(-)
diff --git a/llvm/lib/ObjCopy/MachO/MachOLayoutBuilder.cpp
b/llvm/lib/ObjCopy/MachO/MachOLayoutBuilder.cpp
index d4eb6a9b9fc0b..8ecd669e67178 100644
--- a/llvm/lib/ObjCopy/MachO/MachOLayoutBuilder.cpp
+++ b/llvm/lib/ObjCopy/MachO/MachOLayoutBuilder.cpp
@@ -116,11 +116,10 @@ uint64_t MachOLayoutBuilder::layoutSegments() {
const bool IsObjectFile =
O.Header.FileType == MachO::HeaderFileType::MH_OBJECT;
uint64_t Offset = IsObjectFile ? (HeaderSize + O.Header.SizeOfCmds) : 0;
- if (O.EncryptionInfoCommandIndex) {
- // If we are emitting an encryptable binary, our load commands must have a
- // separate (non-encrypted) page to themselves.
- Offset = alignToPowerOf2(HeaderSize + O.Header.SizeOfCmds, PageSize);
- }
+ // If we are emitting an encryptable binary, our load commands must have a
+ // separate (non-encrypted) page to themselves.
+ bool RequiresFirstSectionOutsideFirstPage =
+ O.EncryptionInfoCommandIndex.has_value();
for (LoadCommand &LC : O.LoadCommands) {
auto &MLC = LC.MachOLoadCommand;
StringRef Segname;
@@ -174,6 +173,10 @@ uint64_t MachOLayoutBuilder::layoutSegments() {
if (!Sec->hasValidOffset()) {
Sec->Offset = 0;
} else {
+ if (RequiresFirstSectionOutsideFirstPage) {
+ SectOffset = alignToPowerOf2(SectOffset, PageSize);
+ RequiresFirstSectionOutsideFirstPage = false;
+ }
Sec->Offset = SegOffset + SectOffset;
Sec->Size = Sec->Content.size();
SegFileSize = std::max(SegFileSize, SectOffset + Sec->Size);
diff --git a/llvm/test/tools/llvm-objcopy/MachO/strip-with-encryption-info.test
b/llvm/test/tools/llvm-objcopy/MachO/strip-with-encryption-info.test
index 19b06b1ec02c8..2b2bd670613de 100644
--- a/llvm/test/tools/llvm-objcopy/MachO/strip-with-encryption-info.test
+++ b/llvm/test/tools/llvm-objcopy/MachO/strip-with-encryption-info.test
@@ -1,13 +1,19 @@
# RUN: rm -rf %t && mkdir %t
# RUN: yaml2obj %s -o %t/original
# RUN: llvm-strip --strip-all %t/original -o %t/stripped
-# RUN: llvm-readobj --macho-segment %t/stripped | FileCheck %s
+# RUN: llvm-readobj --macho-segment --section-headers %t/stripped | FileCheck
%s
+
+# CHECK-LABEL: Sections [
+# CHECK: Index: 0
+# CHECK-NEXT: Name: __text
+# CHECK-NEXT: Segment: __TEXT
+# CHECK: Offset: 16384
# CHECK-LABEL: Name: __PAGEZERO
-# CHECK: fileoff: 16384
+# CHECK: fileoff: 0
# CHECK-LABEL: Name: __TEXT
-# CHECK: fileoff: 16384
+# CHECK: fileoff: 0
# The YAML below is the following code
# int main(int argc, char **argv) { return 0; }
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