[ELF] -z separate-*: Use max-page-size instead of common-page-size fo…

…r text/non-SHF_ALLOC transition and writeTrapInstr For -z separate-code and -z separate-loadable-segments: When RW is present, the RX to RW transition is aligned with max-page-size. When RW is absent, the RX to non-SHF_ALLOC transition should use max-page-size as well.
llvm · Nov 28, 2021 · f9a4d9a · f9a4d9a
1 parent 6c1c231
commit f9a4d9a
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Showing 3 changed files with 27 additions and 25 deletions.
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
@@ -2608,7 +2608,7 @@ template <class ELFT> void Writer<ELFT>::assignFileOffsets() {
     // following section to avoid loading non-segments parts of the file.
     if (config->zSeparate != SeparateSegmentKind::None && lastRX &&
         lastRX->lastSec == sec)
-      off = alignTo(off, config->commonPageSize);
+      off = alignTo(off, config->maxPageSize);
   }
   for (OutputSection *sec : outputSections)
     if (!(sec->flags & SHF_ALLOC))
@@ -2886,9 +2886,9 @@ template <class ELFT> void Writer<ELFT>::writeTrapInstr() {
     for (PhdrEntry *p : part.phdrs)
       if (p->p_type == PT_LOAD && (p->p_flags & PF_X))
         fillTrap(Out::bufferStart + alignDown(p->firstSec->offset + p->p_filesz,
-                                              config->commonPageSize),
+                                              config->maxPageSize),
                  Out::bufferStart + alignTo(p->firstSec->offset + p->p_filesz,
-                                            config->commonPageSize));
+                                            config->maxPageSize));
 
     // Round up the file size of the last segment to the page boundary iff it is
     // an executable segment to ensure that other tools don't accidentally
@@ -2900,7 +2900,7 @@ template <class ELFT> void Writer<ELFT>::writeTrapInstr() {
 
     if (last && (last->p_flags & PF_X))
       last->p_memsz = last->p_filesz =
-          alignTo(last->p_filesz, config->commonPageSize);
+          alignTo(last->p_filesz, config->maxPageSize);
   }
 }
 

diff --git a/lld/test/ELF/fill-trap-ppc.s b/lld/test/ELF/fill-trap-ppc.s
@@ -2,29 +2,29 @@
 
 # RUN: llvm-mc -filetype=obj -triple=powerpc64le-linux %s -o %t.o
 # RUN: ld.lld %t.o -z separate-code -o %t.ppc64le
-# RUN: llvm-readobj -l %t.ppc64le | FileCheck %s
-# RUN: od -Ax -t x1 -N16 -j0x10ff0 %t.ppc64le | FileCheck %s -check-prefix=LE
+# RUN: llvm-readelf -Sl %t.ppc64le | FileCheck %s
+# RUN: od -Ax -t x1 -N16 -j0x1fff0 %t.ppc64le | FileCheck %s -check-prefix=LE
 
 # RUN: llvm-mc -filetype=obj -triple=powerpc64-linux %s -o %t.o
 # RUN: ld.lld %t.o -z separate-code -o %t.ppc64
-# RUN: llvm-readobj -l %t.ppc64 | FileCheck %s
-# RUN: od -Ax -t x1 -N16 -j0x10ff0 %t.ppc64 | FileCheck %s -check-prefix=BE
+# RUN: llvm-readelf -Sl %t.ppc64 | FileCheck %s
+# RUN: od -Ax -t x1 -N16 -j0x1fff0 %t.ppc64 | FileCheck %s -check-prefix=BE
 
-# CHECK: ProgramHeader {
-# CHECK:   Type: PT_LOAD
-# CHECK:        Offset: 0x10000{{$}}
-# CHECK-NEXT:   VirtualAddress:
-# CHECK-NEXT:   PhysicalAddress:
-# CHECK-NEXT:   FileSize: 4096
-# CHECK-NEXT:   MemSize:
-# CHECK-NEXT:   Flags [
-# CHECK-NEXT:     PF_R
-# CHECK-NEXT:     PF_X
-# CHECK-NEXT:   ]
+# CHECK:      [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
+# CHECK-NEXT: [ 0]                   NULL            0000000000000000 000000 000000 00      0   0  0
+# CHECK-NEXT: [ 1] .text             PROGBITS        0000000010010000 010000 000004 00  AX  0   0  4
+## TODO Remove empty .branch_lt
+# CHECK-NEXT: [ 2] .branch_lt        PROGBITS        0000000010020000 020000 000000 00  WA  0   0  8
+# CHECK-NEXT: [ 3] .comment          PROGBITS        0000000000000000 020000 000008 01  MS  0   0  1
+
+# CHECK:      Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
+# CHECK-NEXT: PHDR           0x000040 0x0000000010000040 0x0000000010000040 0x000118 0x000118 R   0x8
+# CHECK-NEXT: LOAD           0x000000 0x0000000010000000 0x0000000010000000 0x000158 0x000158 R   0x10000
+# CHECK-NEXT: LOAD           0x010000 0x0000000010010000 0x0000000010010000 0x010000 0x010000 R E 0x10000
 
 ## Check that executable page is filled with traps at its end.
-# LE: 010ff0 08 00 e0 7f 08 00 e0 7f 08 00 e0 7f 08 00 e0 7f
-# BE: 010ff0 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08
+# LE: 01fff0 08 00 e0 7f 08 00 e0 7f 08 00 e0 7f 08 00 e0 7f
+# BE: 01fff0 7f e0 00 08 7f e0 00 08 7f e0 00 08 7f e0 00 08
 
 .globl _start
 _start:

diff --git a/lld/test/ELF/fill-trap.s b/lld/test/ELF/fill-trap.s
@@ -4,20 +4,22 @@
 ## -z noseparate-code is the default: text segment is not tail padded.
 # RUN: ld.lld %t.o -o %t
 # RUN: llvm-readobj -l %t | FileCheck %s --check-prefixes=CHECK,NOPAD
-# RUN: ld.lld %t.o -z noseparate-code -o %t
+# RUN: ld.lld %t.o -z noseparate-code -z common-page-size=512 -o %t
 # RUN: llvm-readobj -l %t | FileCheck %s --check-prefixes=CHECK,NOPAD
 
 ## -z separate-code pads the tail of text segment with traps.
-# RUN: ld.lld %t.o -z separate-code -o %t
+## Make common-page-size smaller than max-page-size.
+## Check that we use max-page-size instead of common-page-size for padding.
+# RUN: ld.lld %t.o -z separate-code -z common-page-size=512 -o %t
 # RUN: llvm-readobj -l %t | FileCheck %s --check-prefixes=CHECK,PAD
 # RUN: od -Ax -x -N16 -j0x1ff0 %t | FileCheck %s --check-prefix=FILL
 
 ## -z separate-loadable-segments pads all segments, including the text segment.
-# RUN: ld.lld %t.o -z separate-loadable-segments -o %t
+# RUN: ld.lld %t.o -z separate-loadable-segments -z common-page-size=512 -o %t
 # RUN: llvm-readobj -l %t | FileCheck %s --check-prefixes=CHECK,PAD
 # RUN: od -Ax -x -N16 -j0x1ff0 %t | FileCheck %s --check-prefix=FILL
 
-# RUN: ld.lld %t.o -z separate-code -z noseparate-code -o %t
+# RUN: ld.lld %t.o -z separate-code -z noseparate-code -z common-page-size=512 -o %t
 # RUN: llvm-readobj -l %t | FileCheck %s --check-prefixes=CHECK,NOPAD
 
 # CHECK: ProgramHeader {