Correctly align sections.

We have to align the start, not the end.

This should fix crashes on systems where memcpy enforces the expected
alignment.

llvm-svn: 247599

2 files changed, 17 insertions, 2 deletions

diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index 6d1c94ea8f4..f33257ea8ce 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -704,12 +704,14 @@ template <class ELFT> void Writer<ELFT>::assignAddresses() {
     uintX_t Align = Sec->getAlign();
     uintX_t Size = Sec->getSize();
     if (Sec->getFlags() & SHF_ALLOC) {
+      VA = RoundUpToAlignment(VA, Align);
       Sec->setVA(VA);
-      VA += RoundUpToAlignment(Size, Align);
+      VA += Size;
     }
+    FileOff = RoundUpToAlignment(FileOff, Align);
     Sec->setFileOffset(FileOff);
     if (Sec->getType() != SHT_NOBITS)
-      FileOff += RoundUpToAlignment(Size, Align);
+      FileOff += Size;
   }
 
   // Add a PHDR for the dynamic table.
diff --git a/lld/test/elf2/shared.s b/lld/test/elf2/shared.s
index e0ad621fbef..1140c9425ac 100644
--- a/lld/test/elf2/shared.s
+++ b/lld/test/elf2/shared.s
@@ -1,10 +1,23 @@
 // RUN: llvm-mc -filetype=obj -triple=i686-unknown-linux %s -o %t.o
 // RUN: llvm-mc -filetype=obj -triple=i686-unknown-linux %p/Inputs/shared.s -o %t2.o
 // RUN: lld -flavor gnu2 -shared %t2.o -o %t2.so
+// RUN: llvm-readobj -s %t2.so | FileCheck --check-prefix=SO %s
 // RUN: lld -flavor gnu2 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -rpath foo -rpath bar %t.o %t2.so -o %t
 // RUN: llvm-readobj --program-headers --dynamic-table -t -s -dyn-symbols -section-data %t | FileCheck %s
 // REQUIRES: x86
 
+// Make sure .symtab is properly aligned.
+// SO:      Name: .symtab
+// SO-NEXT: Type: SHT_SYMTAB
+// SO-NEXT: Flags [
+// SO-NEXT: ]
+// SO-NEXT: Address:
+// SO-NEXT: Offset: 0x300C
+// SO-NEXT: Size:
+// SO-NEXT: Link:
+// SO-NEXT: Info:
+// SO-NEXT: AddressAlignment: 4
+
 // CHECK:        Name: .interp
 // CHECK-NEXT:   Type: SHT_PROGBITS
 // CHECK-NEXT:   Flags [