RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-02-13 17:00:01 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[llvm-readelf] - Do not enter an infinite loop when printing histogram.

Browse Source 
This is similar to D68086.
We are entering an infinite loop when dumping a histogram for a specially crafted
.hash section with a loop in a chain.

Differential revision: https://reviews.llvm.org/D68771

llvm-svn: 374344
This commit is contained in:
George Rimar 2019-10-10 13:26:26 +00:00
parent f1020fe73e
commit c1874049a8
2 changed files with 80 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

91
test/tools/llvm-readobj/elf-hash-histogram.test
View File

@ -1,27 +1,70 @@
RUN: llvm-readelf --elf-hash-histogram %p/Inputs/gnuhash.so.elf-ppc64 \
RUN: | FileCheck %s -check-prefix PPC64GNU
RUN: llvm-readelf --elf-hash-histogram %p/Inputs/gnuhash.so.elf-x86_64 \
RUN: | FileCheck %s -check-prefix X86GNU
RUN: llvm-readelf --elf-hash-histogram %p/Inputs/got-plt.exe.elf-mipsel \
RUN: | FileCheck %s -check-prefix SYSV
# RUN: llvm-readelf --elf-hash-histogram %p/Inputs/gnuhash.so.elf-ppc64 \
# RUN: | FileCheck %s -check-prefix PPC64GNU
# RUN: llvm-readelf --elf-hash-histogram %p/Inputs/gnuhash.so.elf-x86_64 \
# RUN: | FileCheck %s -check-prefix X86GNU
# RUN: llvm-readelf --elf-hash-histogram %p/Inputs/got-plt.exe.elf-mipsel \
# RUN: | FileCheck %s -check-prefix SYSV
PPC64GNU: Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
PPC64GNU-NEXT: Length Number % of total Coverage
PPC64GNU-NEXT: 0 1 ( 33.3%) 0.0%
PPC64GNU-NEXT: 1 1 ( 33.3%) 25.0%
PPC64GNU-NEXT: 2 0 ( 0.0%) 25.0%
PPC64GNU-NEXT: 3 1 ( 33.3%) 100.0%
# PPC64GNU: Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
# PPC64GNU-NEXT: Length Number % of total Coverage
# PPC64GNU-NEXT: 0 1 ( 33.3%) 0.0%
# PPC64GNU-NEXT: 1 1 ( 33.3%) 25.0%
# PPC64GNU-NEXT: 2 0 ( 0.0%) 25.0%
# PPC64GNU-NEXT: 3 1 ( 33.3%) 100.0%
X86GNU: Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
X86GNU-NEXT: Length Number % of total Coverage
X86GNU-NEXT: 0 1 ( 33.3%) 0.0%
X86GNU-NEXT: 1 1 ( 33.3%) 25.0%
X86GNU-NEXT: 2 0 ( 0.0%) 25.0%
X86GNU-NEXT: 3 1 ( 33.3%) 100.0%
# X86GNU: Histogram for `.gnu.hash' bucket list length (total of 3 buckets)
# X86GNU-NEXT: Length Number % of total Coverage
# X86GNU-NEXT: 0 1 ( 33.3%) 0.0%
# X86GNU-NEXT: 1 1 ( 33.3%) 25.0%
# X86GNU-NEXT: 2 0 ( 0.0%) 25.0%
# X86GNU-NEXT: 3 1 ( 33.3%) 100.0%
SYSV: Histogram for bucket list length (total of 3 buckets)
SYSV-NEXT: Length Number % of total Coverage
SYSV-NEXT: 0 0 ( 0.0%) 0.0%
SYSV-NEXT: 1 0 ( 0.0%) 0.0%
SYSV-NEXT: 2 2 ( 66.7%) 57.1%
SYSV-NEXT: 3 1 ( 33.3%) 100.0%
# SYSV: Histogram for bucket list length (total of 3 buckets)
# SYSV-NEXT: Length Number % of total Coverage
# SYSV-NEXT: 0 0 ( 0.0%) 0.0%
# SYSV-NEXT: 1 0 ( 0.0%) 0.0%
# SYSV-NEXT: 2 2 ( 66.7%) 57.1%
# SYSV-NEXT: 3 1 ( 33.3%) 100.0%
## Show that we report a warning for a hash table which contains an entry of
## the bucket array pointing to a cycle.
# RUN: yaml2obj %s -o %t.o
# RUN: llvm-readelf --elf-hash-histogram 2>&1 %t.o | FileCheck -DFILE=%t.o %s --check-prefix BROKEN
# BROKEN: warning: '[[FILE]]': .hash section is invalid: bucket 1: a cycle was detected in the linked chain
# BROKEN: Histogram for bucket list length (total of 1 buckets)
# BROKEN-NEXT: Length Number % of total Coverage
# BROKEN-NEXT: 0 0 ( 0.0%) 0.0%
# BROKEN-NEXT: 1 1 (100.0%) 100.0%
--- !ELF
FileHeader:
Class: ELFCLASS32
Data: ELFDATA2LSB
Type: ET_REL
Machine: EM_386
Sections:
- Name: .hash
Type: SHT_HASH
Link: .dynsym
Bucket: [ 1 ]
Chain: [ 0, 1 ]
- Name: .dynamic
Type: SHT_DYNAMIC
Flags: [ SHF_ALLOC ]
Entries:
## llvm-readelf will read the hash table from the file offset
## p_offset + (p_vaddr - DT_HASH) = p_offset + (0 - 0) = p_offset,
## which is the start of PT_LOAD, i.e. the file offset of .hash.
- Tag: DT_HASH
Value: 0x0
- Tag: DT_NULL
Value: 0
DynamicSymbols:
- Name: foo
ProgramHeaders:
- Type: PT_LOAD
Sections:
- Section: .hash
- Section: .dynamic

14
tools/llvm-readobj/ELFDumper.cpp
View File

@ -3968,9 +3968,21 @@ void GNUStyle<ELFT>::printHashHistogram(const ELFFile<ELFT> *Obj) {
// Go over all buckets and and note chain lengths of each bucket (total
// unique chain lengths).
for (size_t B = 0; B < NBucket; B++) {
for (size_t C = Buckets[B]; C > 0 && C < NChain; C = Chains[C])
std::vector<bool> Visited(NChain);
for (size_t C = Buckets[B]; C < NChain; C = Chains[C]) {
if (C == ELF::STN_UNDEF)
break;
if (Visited[C]) {
reportWarning(
createError(".hash section is invalid: bucket " + Twine(C) +
": a cycle was detected in the linked chain"),
this->FileName);
break;
}
Visited[C] = true;
if (MaxChain <= ++ChainLen[B])
MaxChain++;
}
TotalSyms += ChainLen[B];
}