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[ELF] - Report error when memory region is overflowed by data commands. 

LLD can not catch a memory area overflow when using a data command.
If we have the script below:

.foo : 
{
  *(.foo)
  BYTE(0x1)
} > ram

where BYTE overflows the ram region, we do not report it currently.
Patch fixes that.

Differential revision: https://reviews.llvm.org/D43948

llvm-svn: 326545
This commit is contained in:
George Rimar 2018-03-02 08:11:58 +00:00
parent 7e55245213
commit 97785af464
2 changed files with 37 additions and 12 deletions
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27
lld/ELF/LinkerScript.cpp
View File

@ -621,6 +621,16 @@ uint64_t LinkerScript::advance(uint64_t Size, unsigned Alignment) {
return End;
}
// Expands the memory region by the specified size.
static void expandMemoryRegion(MemoryRegion *MemRegion, uint64_t Size,
StringRef RegionName, StringRef SecName) {
MemRegion->CurPos += Size;
uint64_t NewSize = MemRegion->CurPos - MemRegion->Origin;
if (NewSize > MemRegion->Length)
error("section '" + SecName + "' will not fit in region '" + RegionName +
"': overflowed by " + Twine(NewSize - MemRegion->Length) + " bytes");
}
void LinkerScript::output(InputSection *S) {
uint64_t Before = advance(0, 1);
uint64_t Pos = advance(S->getSize(), S->Alignment);
@ -637,17 +647,9 @@ void LinkerScript::output(InputSection *S) {
Ctx->LMARegion->CurPos += Pos - Before;
// FIXME: should we also produce overflow errors for LMARegion?
if (Ctx->MemRegion) {
uint64_t &CurOffset = Ctx->MemRegion->CurPos;
CurOffset += Pos - Before;
uint64_t CurSize = CurOffset - Ctx->MemRegion->Origin;
if (CurSize > Ctx->MemRegion->Length) {
uint64_t OverflowAmt = CurSize - Ctx->MemRegion->Length;
error("section '" + Ctx->OutSec->Name + "' will not fit in region '" +
Ctx->MemRegion->Name + "': overflowed by " + Twine(OverflowAmt) +
" bytes");
}
}
if (Ctx->MemRegion)
expandMemoryRegion(Ctx->MemRegion, Pos - Before, Ctx->MemRegion->Name,
Ctx->OutSec->Name);
}
void LinkerScript::switchTo(OutputSection *Sec) {
@ -738,7 +740,8 @@ void LinkerScript::assignOffsets(OutputSection *Sec) {
Cmd->Offset = Dot - Ctx->OutSec->Addr;
Dot += Cmd->Size;
if (Ctx->MemRegion)
Ctx->MemRegion->CurPos += Cmd->Size;
expandMemoryRegion(Ctx->MemRegion, Cmd->Size, Ctx->MemRegion->Name,
Ctx->OutSec->Name);
if (Ctx->LMARegion)
Ctx->LMARegion->CurPos += Cmd->Size;
Ctx->OutSec->Size = Dot - Ctx->OutSec->Addr;

22
lld/test/ELF/linkerscript/memory-data-commands.test Normal file
View File

@ -0,0 +1,22 @@
# REQUIRES: x86
# RUN: echo ".section .foo,\"a\"" > %t.s
# RUN: echo ".quad 1" >> %t.s
# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
# RUN: not ld.lld -o %t %t.o --script %s 2>&1 | FileCheck %s
# Check we are able to catch 'ram' overflow caused by BYTE command.
# CHECK: error: section '.foo' will not fit in region 'ram': overflowed by 1 bytes
MEMORY {
text (rwx): org = 0x0, len = 0x1000
ram (rwx): org = 0x1000, len = 8
}
SECTIONS {
.text : { *(.text) } > text
.foo : {
*(.foo)
BYTE(0x1)
} > ram
}