https://github.com/aeubanks updated
https://github.com/llvm/llvm-project/pull/73045
>From 0145020ef2a803ec797e42f95bacde05dc32eac1 Mon Sep 17 00:00:00 2001
From: Arthur Eubanks <aeuba...@google.com>
Date: Tue, 21 Nov 2023 14:01:04 -0800
Subject: [PATCH 1/3] [lld/ELF] Hint if R_X86_64_PC32 overflows and references
a SHF_X86_64_LARGE section
Makes it clearer what the issue is when hand-written assembly doesn't follow
medium code model assumptions in a medium code model build.
Alternative to #71248 by only hinting on an overflow.
---
lld/ELF/Relocations.cpp | 6 ++++++
lld/test/ELF/x86-64-pc32-overflow-large.s | 25 +++++++++++++++++++++++
2 files changed, 31 insertions(+)
create mode 100644 lld/test/ELF/x86-64-pc32-overflow-large.s
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index fe3d7f419e84aa6..37a2363094020d0 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -105,6 +105,12 @@ void elf::reportRangeError(uint8_t *loc, const Relocation
&rel, const Twine &v,
hint = "; references '" + lld::toString(*rel.sym) + '\'';
else if (auto *d = dyn_cast<Defined>(rel.sym))
hint = ("; references section '" + d->section->name + "'").str();
+
+ if (rel.type == R_X86_64_PC32 && rel.sym->getOutputSection() &&
+ (rel.sym->getOutputSection()->flags & SHF_X86_64_LARGE)) {
+ hint += "; a R_X86_64_PC32 relocation should not reference a section "
+ "marked SHF_X86_64_LARGE";
+ }
}
if (!errPlace.srcLoc.empty())
hint += "\n>>> referenced by " + errPlace.srcLoc;
diff --git a/lld/test/ELF/x86-64-pc32-overflow-large.s
b/lld/test/ELF/x86-64-pc32-overflow-large.s
new file mode 100644
index 000000000000000..54c20eddfd04c33
--- /dev/null
+++ b/lld/test/ELF/x86-64-pc32-overflow-large.s
@@ -0,0 +1,25 @@
+# REQUIRES: x86
+# RUN: split-file %s %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %t/a.s -o %t/a.o
+# RUN: not ld.lld %t/a.o -T %t/lds -o /dev/null 2>&1 | FileCheck %s
+
+# CHECK: error: {{.*}}a.o:(.text+{{.*}}): relocation R_X86_64_PC32 out of
range: {{.*}}; a R_X86_64_PC32 relocation should not reference a section marked
SHF_X86_64_LARGE
+
+#--- a.s
+.text
+.globl _start
+.type _start, @function
+_start:
+ movq hello(%rip), %rax
+
+.section ldata,"awl",@progbits
+.type hello, @object
+.globl hello
+hello:
+.long 1
+
+#--- lds
+SECTIONS {
+ .text 0x100000 : { *(.text) }
+ ldata 0x80200000 : { *(ldata) }
+}
>From a4432ade194df8dedb7b4990a29efaa4e822d486 Mon Sep 17 00:00:00 2001
From: Arthur Eubanks <aeuba...@google.com>
Date: Wed, 17 Jan 2024 19:20:39 +0000
Subject: [PATCH 2/3] check emachine
---
lld/ELF/Relocations.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index e1e047c3d052427..10f62f21274239b 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -106,7 +106,8 @@ void elf::reportRangeError(uint8_t *loc, const Relocation
&rel, const Twine &v,
else if (auto *d = dyn_cast<Defined>(rel.sym))
hint = ("; references section '" + d->section->name + "'").str();
- if (rel.type == R_X86_64_PC32 && rel.sym->getOutputSection() &&
+ if (config->emachine == EM_X86_64 && rel.type == R_X86_64_PC32 &&
+ rel.sym->getOutputSection() &&
(rel.sym->getOutputSection()->flags & SHF_X86_64_LARGE)) {
hint += "; a R_X86_64_PC32 relocation should not reference a section "
"marked SHF_X86_64_LARGE";
>From 4447d474587ebf06d8b778616ef8c96c7cbd3c46 Mon Sep 17 00:00:00 2001
From: Arthur Eubanks <aeuba...@google.com>
Date: Wed, 17 Jan 2024 23:29:55 +0000
Subject: [PATCH 3/3] update error message
---
lld/ELF/Relocations.cpp | 4 ++--
lld/test/ELF/x86-64-pc32-overflow-large.s | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 10f62f21274239b..59b022079587175 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -109,8 +109,8 @@ void elf::reportRangeError(uint8_t *loc, const Relocation
&rel, const Twine &v,
if (config->emachine == EM_X86_64 && rel.type == R_X86_64_PC32 &&
rel.sym->getOutputSection() &&
(rel.sym->getOutputSection()->flags & SHF_X86_64_LARGE)) {
- hint += "; a R_X86_64_PC32 relocation should not reference a section "
- "marked SHF_X86_64_LARGE";
+ hint += "; R_X86_64_PC32 should not reference a section marked "
+ "SHF_X86_64_LARGE";
}
}
if (!errPlace.srcLoc.empty())
diff --git a/lld/test/ELF/x86-64-pc32-overflow-large.s
b/lld/test/ELF/x86-64-pc32-overflow-large.s
index 54c20eddfd04c33..fb8f3e4480c40f5 100644
--- a/lld/test/ELF/x86-64-pc32-overflow-large.s
+++ b/lld/test/ELF/x86-64-pc32-overflow-large.s
@@ -3,7 +3,7 @@
# RUN: llvm-mc -filetype=obj -triple=x86_64 %t/a.s -o %t/a.o
# RUN: not ld.lld %t/a.o -T %t/lds -o /dev/null 2>&1 | FileCheck %s
-# CHECK: error: {{.*}}a.o:(.text+{{.*}}): relocation R_X86_64_PC32 out of
range: {{.*}}; a R_X86_64_PC32 relocation should not reference a section marked
SHF_X86_64_LARGE
+# CHECK: error: {{.*}}a.o:(.text+{{.*}}): relocation R_X86_64_PC32 out of
range: {{.*}}; R_X86_64_PC32 should not reference a section marked
SHF_X86_64_LARGE
#--- a.s
.text
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