## Here we test the --elf-hash-histogram command line option. ## This test case checks how we built histograms for hash sections. # RUN: yaml2obj --docnum=1 -D BITS=32 %s -o %t1-32.o # RUN: llvm-readelf --elf-hash-histogram %t1-32.o | FileCheck %s --check-prefix=HIST ## Test --histogram and -I aliases. # RUN: llvm-readelf --histogram %t1-32.o | FileCheck %s --check-prefix=HIST # RUN: llvm-readelf -I %t1-32.o | FileCheck %s --check-prefix=HIST # RUN: yaml2obj --docnum=1 -D BITS=64 %s -o %t1-64.o # RUN: llvm-readelf --elf-hash-histogram %t1-64.o | FileCheck %s --check-prefix=HIST # HIST: Histogram for bucket list length (total of 3 buckets) # HIST-NEXT: Length Number % of total Coverage # HIST-NEXT: 0 2 ( 66.7%) 0.0% # HIST-NEXT: 1 0 ( 0.0%) 0.0% # HIST-NEXT: 2 0 ( 0.0%) 0.0% # HIST-NEXT: 3 1 ( 33.3%) 100.0% # HIST-NEXT: Histogram for `.gnu.hash' bucket list length (total of 3 buckets) # HIST-NEXT: Length Number % of total Coverage # HIST-NEXT: 0 1 ( 33.3%) 0.0% # HIST-NEXT: 1 1 ( 33.3%) 25.0% # HIST-NEXT: 2 0 ( 0.0%) 25.0% # HIST-NEXT: 3 1 ( 33.3%) 100.0% # HIST-NOT: {{.}} --- !ELF FileHeader: Class: ELFCLASS[[BITS]] Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .hash Type: SHT_HASH Flags: [ SHF_ALLOC ] Bucket: [ 6, 4, 5 ] Chain: [ 0, 0, 1, 0, 2 ] - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: SymNdx: 0x1 Shift2: 0x0 BloomFilter: [ 0x0 ] HashBuckets: [ 0x00000001, 0x00000004, 0x00000000 ] HashValues: [ 0x0B887388, 0xECD54542, 0x7C92E3BB, 0x1C5871D9 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_WRITE, SHF_ALLOC ] Entries: - Tag: DT_HASH Value: 0x0 - Tag: DT_GNU_HASH ## sizeof(.hash) == 0x28. Value: 0x28 - Tag: DT_NULL Value: 0x0 DynamicSymbols: - Name: a - Name: b - Name: c - Name: d ProgramHeaders: - Type: PT_LOAD FirstSec: .hash LastSec: .dynamic ## Show that we report a warning for a hash table which contains an entry of ## the bucket array pointing to a cycle. # RUN: yaml2obj --docnum=2 %s -o %t2.o # RUN: llvm-readelf --elf-hash-histogram 2>&1 %t2.o | \ # RUN: FileCheck -DFILE=%t2.o %s --check-prefix=BROKEN --implicit-check-not=warning: # 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 2 buckets) # BROKEN-NEXT: Length Number % of total Coverage # BROKEN-NEXT: 0 0 ( 0.0%) 0.0% # BROKEN-NEXT: 1 2 (100.0%) 100.0% --- !ELF FileHeader: Class: ELFCLASS32 Data: ELFDATA2LSB Type: ET_REL Sections: - Name: .hash Type: SHT_HASH Link: .dynsym Bucket: [ 1, 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 FirstSec: .hash LastSec: .dynamic ## Each SHT_HASH section starts with two 32-bit fields: nbucket and nchain. ## Check we report an error when a DT_HASH value points to data that has size less than 8 bytes. # RUN: yaml2obj --docnum=3 %s -o %t3.o # RUN: llvm-readelf --elf-hash-histogram %t3.o 2>&1 | FileCheck %s --check-prefix=ERR1 -DFILE=%t3.o # ERR1: warning: '[[FILE]]': the hash table at offset 0x2b1 goes past the end of the file (0x2b8){{$}} --- !ELF FileHeader: Class: ELFCLASS64 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .hash Type: SHT_HASH Flags: [ SHF_ALLOC ] Bucket: [ 0 ] Chain: [ 0 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_WRITE, SHF_ALLOC ] Entries: - Tag: DT_HASH Value: 0x239 - Tag: DT_NULL Value: 0x0 DynamicSymbols: [] ProgramHeaders: - Type: PT_LOAD FileSize: 0x23a FirstSec: .hash LastSec: .dynamic ## Check we report a warning when the hash table goes past the end of the file. ## Case A.1: the hash table ends right before the EOF. We have a broken nbucket ## field that has a value larger than the number of buckets. # RUN: yaml2obj --docnum=4 %s -o %t4.1.o -DNBUCKET=0x5d -DNCHAIN=0x1 # RUN: llvm-readelf --elf-hash-histogram %t4.1.o 2>&1 | \ # RUN: FileCheck %s --implicit-check-not={{.}} --allow-empty ## Case A.2: the hash table ends 1 byte past the EOF. We have a broken nbucket ## field that has a value larger than the number of buckets. # RUN: yaml2obj --docnum=4 %s -o %t4.2.o -DNBUCKET=0x5e -DNCHAIN=0x1 # RUN: llvm-readelf --elf-hash-histogram %t4.2.o 2>&1 | \ # RUN: FileCheck %s --check-prefix=ERR2 -DFILE=%t4.2.o --implicit-check-not="warning:" # ERR2: warning: '[[FILE]]': the hash table at offset 0x54 goes past the end of the file (0x1d4), nbucket = 94, nchain = 1{{$}} ## Case B.1: the hash table ends right before the EOF. We have a broken nchain ## field that has a value larger than the number of chains. # RUN: yaml2obj --docnum=4 %s -o %t4.3.o -DNBUCKET=0x1 -DNCHAIN=0x5d # RUN: llvm-readelf --elf-hash-histogram %t4.3.o 2>&1 | \ # RUN: FileCheck %s --check-prefix=ERR3 -DFILE=%t4.3.o --implicit-check-not="warning:" # ERR3: warning: '[[FILE]]': hash table nchain (93) differs from symbol count derived from SHT_DYNSYM section header (1){{$}} # ERR3: warning: '[[FILE]]': the size (0x5d0) of the dynamic symbol table at 0x78, derived from the hash table, goes past the end of the file (0x1d4) and will be ignored ## Case B.2: the hash table ends 1 byte past the EOF. We have a broken nchain ## field that has a value larger than the number of chains. # RUN: yaml2obj --docnum=4 %s -o %t4.4.o -DNBUCKET=0x1 -DNCHAIN=0x5e # RUN: llvm-readelf --elf-hash-histogram %t4.4.o 2>&1 | \ # RUN: FileCheck %s --check-prefix=ERR4 -DFILE=%t4.4.o --implicit-check-not="warning:" # ERR4: warning: '[[FILE]]': hash table nchain (94) differs from symbol count derived from SHT_DYNSYM section header (1){{$}} # ERR4: warning: '[[FILE]]': the size (0x5e0) of the dynamic symbol table at 0x78, derived from the hash table, goes past the end of the file (0x1d4) and will be ignored # ERR4: warning: '[[FILE]]': the hash table at offset 0x54 goes past the end of the file (0x1d4), nbucket = 1, nchain = 94{{$}} --- !ELF FileHeader: Class: ELFCLASS32 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .hash Type: SHT_HASH Flags: [ SHF_ALLOC ] Bucket: [ 0 ] NBucket: [[NBUCKET]] Chain: [ 0 ] NChain: [[NCHAIN]] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_WRITE, SHF_ALLOC ] Entries: - Tag: DT_HASH Value: 0x0 - Tag: DT_NULL Value: 0x0 DynamicSymbols: [] ProgramHeaders: - Type: PT_LOAD FirstSec: .hash LastSec: .dynamic ## Check we dump a histogram for the .gnu.hash table even when the .hash table is skipped. ## Case A: the .hash table has no data to build histogram and it is skipped. # RUN: yaml2obj --docnum=5 %s -o %t5.o # RUN: llvm-readelf --elf-hash-histogram %t5.o 2>&1 | \ # RUN: FileCheck %s --check-prefix=GNU-HASH --implicit-check-not="Histogram" ## Case B: the .hash table has a broken nbucket field. We report a warning ## and skip dumping of the .hash table. # RUN: yaml2obj --docnum=5 -DNBUCKET=0xffffffff %s -o %t6.o # RUN: llvm-readelf --elf-hash-histogram %t6.o 2>&1 | \ # RUN: FileCheck %s -DFILE=%t6.o --check-prefixes=WARN,GNU-HASH # WARN: warning: '[[FILE]]': the hash table at offset 0x78 goes past the end of the file (0x358), nbucket = 4294967295, nchain = 2 # GNU-HASH: Histogram for `.gnu.hash' bucket list length (total of 3 buckets) --- !ELF FileHeader: Class: ELFCLASS64 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .hash Type: SHT_HASH Flags: [ SHF_ALLOC ] Bucket: [ 0 ] ## 0x2 is a no-op: it does not change the number of buckets described by the "Bucket" key NBucket: [[NBUCKET=0x2]] Chain: [ 0, 0 ] - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: SymNdx: 0x1 Shift2: 0x0 BloomFilter: [ 0x0 ] HashBuckets: [ 0x00000001, 0x00000004, 0x00000000 ] HashValues: [ 0x0B887388 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_WRITE, SHF_ALLOC ] Entries: - Tag: DT_HASH Value: 0x0 - Tag: DT_GNU_HASH ## sizeof(.hash) == 0x14. Value: 0x14 - Tag: DT_NULL Value: 0x0 DynamicSymbols: - Name: foo ProgramHeaders: - Type: PT_LOAD FirstSec: .hash LastSec: .dynamic ## Check we report a proper warning when the GNU hash table goes past the end of the file. ## Case A: the 'maskwords' field is set so that the GNU hash table goes past the end of the file. # RUN: yaml2obj --docnum=6 -D MASKWORDS=0x80000000 %s -o %t7 # RUN: llvm-readelf --elf-hash-histogram %t7 2>&1 | \ # RUN: FileCheck %s -DFILE=%t7 --check-prefix=ERR5 --implicit-check-not="Histogram" # ERR5: warning: '[[FILE]]': unable to dump the SHT_GNU_HASH section at 0x78: it goes past the end of the file ## Case B: the 'nbuckets' field is set so that the GNU hash table goes past the end of the file. # RUN: yaml2obj --docnum=6 -D NBUCKETS=0x80000000 %s -o %t8 # RUN: llvm-readelf --elf-hash-histogram %t8 2>&1 | \ # RUN: FileCheck %s -DFILE=%t8 --check-prefix=ERR5 --implicit-check-not="Histogram" --- !ELF FileHeader: Class: ELFCLASS64 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: SymNdx: 0x0 Shift2: 0x0 ## The number of words in the Bloom filter. The value of 1 is no-op. MaskWords: [[MASKWORDS=1]] ## The number of hash buckets. The value of 1 is no-op. NBuckets: [[NBUCKETS=1]] BloomFilter: [ 0x0 ] HashBuckets: [ 0x0 ] HashValues: [ 0x0 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_ALLOC ] Link: .dynstr Entries: - Tag: DT_GNU_HASH Value: 0x0 - Tag: DT_NULL Value: 0x0 DynamicSymbols: [] ProgramHeaders: - Type: PT_LOAD FirstSec: .gnu.hash LastSec: .dynamic ## Linkers might produce an empty no-op SHT_GNU_HASH section when ## there are no dynamic symbols or when all dynamic symbols are undefined. ## Such sections normally have a single zero entry in the bloom ## filter, a single zero entry in the hash bucket and no values. ## ## The index of the first symbol in the dynamic symbol table ## included in the hash table can be set to the number of dynamic symbols, ## which is one larger than the index of the last dynamic symbol. ## For empty tables however, this value is unimportant and can be ignored. ## Check the case when a 'symndx' index of the first symbol in the dynamic symbol ## table is larger than the number of dynamic symbols. ## Case A: when the buckets array is not empty and has a non-zero value we report a warning. # RUN: yaml2obj --docnum=7 -DVAL=0x1 %s -o %t9 # RUN: llvm-readelf --elf-hash-histogram %t9 2>&1 | \ # RUN: FileCheck %s -DFILE=%t9 --check-prefix=ERR6 # ERR6: warning: '[[FILE]]': unable to print the GNU hash table histogram: the first hashed symbol index (16) is greater than or equal to the number of dynamic symbols (1) ## Case B: we do not report a warning when the buckets array contains only zero values. # RUN: yaml2obj --docnum=7 -DVAL=0x0 %s -o %t10 # RUN: llvm-readelf --elf-hash-histogram %t10 2>&1 | \ # RUN: FileCheck %s --allow-empty --implicit-check-not="Histogram" ## Case C: we do not report a warning when the buckets array is empty. # RUN: yaml2obj --docnum=7 -DVAL="" %s -o %t11 # RUN: llvm-readelf --elf-hash-histogram %t11 2>&1 | \ # RUN: FileCheck %s --allow-empty --implicit-check-not="Histogram" --- !ELF FileHeader: Class: ELFCLASS64 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: SymNdx: 0x10 Shift2: 0x0 BloomFilter: [ 0x0 ] HashBuckets: [ [[VAL]] ] HashValues: [ 0x0 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_ALLOC ] Link: .dynstr Entries: - Tag: DT_GNU_HASH Value: 0x0 - Tag: DT_NULL Value: 0x0 DynamicSymbols: [] ProgramHeaders: - Type: PT_LOAD FirstSec: .gnu.hash LastSec: .dynamic ## Check we report warnings when the dynamic symbol table is absent or empty. ## The code locates the dynamic symbol table by the section type. Use SHT_PROGBITS to hide it. # RUN: yaml2obj --docnum=8 -DTYPE=SHT_PROGBITS %s -o %t12 # RUN: llvm-readelf --elf-hash-histogram %t12 2>&1 | \ # RUN: FileCheck %s -DFILE=%t12 --check-prefix=ERR7 # ERR7: warning: '[[FILE]]': unable to print the GNU hash table histogram: no dynamic symbol table found # RUN: yaml2obj --docnum=8 -DTYPE=SHT_DYNSYM %s -o %t13 # RUN: llvm-readelf --elf-hash-histogram %t13 2>&1 | \ # RUN: FileCheck %s -DFILE=%t13 --check-prefix=ERR8 # ERR8: warning: '[[FILE]]': unable to print the GNU hash table histogram: the dynamic symbol table is empty --- !ELF FileHeader: Class: ELFCLASS64 Data: ELFDATA2LSB Type: ET_DYN Sections: - Name: .gnu.hash Type: SHT_GNU_HASH Flags: [ SHF_ALLOC ] Header: SymNdx: 0x0 Shift2: 0x0 BloomFilter: [ 0x0 ] HashBuckets: [ 0x0 ] HashValues: [ 0x0 ] - Name: .dynamic Type: SHT_DYNAMIC Flags: [ SHF_ALLOC ] Entries: - Tag: DT_GNU_HASH Value: 0x0 - Tag: DT_NULL Value: 0x0 - Name: .dynsym Type: [[TYPE]] Size: 0 ProgramHeaders: - Type: PT_LOAD FirstSec: .gnu.hash LastSec: .gnu.hash