Hi Omar,
On Sat, 2020-03-21 at 11:21 -0700, Omar Sandoval wrote:
> I encountered this in drgn on a vmcore for a large server created by
> makedumpfile,
That makes sense since [vm]cores contain lots of segments.
> but I was able to put together a minimal reproducer.
> Generate the ELF file with this python script:
> [...]
>
> And run this program:
> [...]
>
> This should output 66000, but it outputs 65535 instead.
That is a really nice testcase. If we tweak it a little (so all
segments have the same load address) then it compresses to just 188
bytes with bzip2. Would you mind, and give your signed-off-by, for
adding the attached to the testsuite? It fails before, and passes after
your fix.
> Looking at file_read_elf, the cache is only initialized from
> elf_begin
> from ELF_C_RDWR_MMAP and ELF_C_READ_MMAP_PRIVATE as long as
> endianness
> matches the host and the section headers are properly aligned:
>
> if (map_address != NULL && e_ident[EI_DATA] == MY_ELFDATA
> && cmd != ELF_C_READ_MMAP /* We need a copy to be able to
> write. */
> && (ALLOW_UNALIGNED
> || (((uintptr_t) ((char *) ehdr + e_shoff)
> & (__alignof__ (Elf64_Shdr) - 1)) == 0)))
I had missed that part. So it is actually common to not have the phdrs
cache.
Thanks,
Mark
From 28734adeb8cd51c7124330f88c1dc49c9c187865 Mon Sep 17 00:00:00 2001
From: Mark Wielaard <m...@klomp.org>
Date: Sun, 22 Mar 2020 23:14:24 +0100
Subject: [PATCH] tests: Add testcase for elf_getphdrnum with more than 65535
entries.
Signed-off-by: Mark Wielaard <m...@klomp.org>
---
tests/ChangeLog | 11 +++
tests/Makefile.am | 10 ++-
tests/getphdrnum.c | 42 +++++++++++
tests/run-getphdrnum.sh | 137 +++++++++++++++++++++++++++++++++++
tests/testfile-phdrs.elf.bz2 | Bin 0 -> 188 bytes
5 files changed, 197 insertions(+), 3 deletions(-)
create mode 100644 tests/getphdrnum.c
create mode 100755 tests/run-getphdrnum.sh
create mode 100644 tests/testfile-phdrs.elf.bz2
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 33a5cf62..887c233a 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,14 @@
+2020-03-22 Omar Sandoval <osan...@fb.com>
+ Mark Wielaard <m...@klomp.org>
+
+ * getphdrnum.c: New file.
+ * run-getphdrnum.sh: New test.
+ * testfile-phdrs.elf.bz2: New test file.
+ * Makefile.am (check_PROGRAMS): Add getphdrnum.
+ (TESTS): Add run-getphdrnum.sh.
+ (EXTRA_DIST): Add run-getphdrnum.sh and testfile-phdrs.elf.bz2.
+ (getphdrnum_LDADD): New variable.
+
2020-02-19 Aaron Merey <ame...@redhat.com>
* run-debuginfod-find.sh: Run tests for verifying default
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a83c3d67..934110e0 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -62,7 +62,8 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \
get-units-invalid get-units-split attr-integrate-skel \
all-dwarf-ranges unit-info next_cfi \
elfcopy addsections xlate_notes elfrdwrnop \
- dwelf_elf_e_machine_string
+ dwelf_elf_e_machine_string \
+ getphdrnum
asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \
asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -168,7 +169,8 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
run-dwelf_elf_e_machine_string.sh \
run-elfclassify.sh run-elfclassify-self.sh \
run-disasm-riscv64.sh \
- run-pt_gnu_prop-tests.sh
+ run-pt_gnu_prop-tests.sh \
+ run-getphdrnum.sh
if !BIARCH
export ELFUTILS_DISABLE_BIARCH = 1
@@ -476,7 +478,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
debuginfod-tars/pacman-sources/README.md \
debuginfod-tars/pacman-sources/hello.c \
run-pt_gnu_prop-tests.sh \
- testfile_pt_gnu_prop.bz2 testfile_pt_gnu_prop32.bz2
+ testfile_pt_gnu_prop.bz2 testfile_pt_gnu_prop32.bz2 \
+ run-getphdrnum.sh testfile-phdrs.elf.bz2
if USE_VALGRIND
@@ -654,6 +657,7 @@ debuginfod_build_id_find_LDADD = $(libelf) $(libdw)
xlate_notes_LDADD = $(libelf)
elfrdwrnop_LDADD = $(libelf)
dwelf_elf_e_machine_string_LDADD = $(libelf) $(libdw)
+getphdrnum_LDADD = $(libelf) $(libdw)
# We want to test the libelf header against the system elf.h header.
# Don't include any -I CPPFLAGS. Except when we install our own elf.h.
diff --git a/tests/getphdrnum.c b/tests/getphdrnum.c
new file mode 100644
index 00000000..6ab51e22
--- /dev/null
+++ b/tests/getphdrnum.c
@@ -0,0 +1,42 @@
+#include <elfutils/libdwelf.h>
+#include <fcntl.h>
+#include <libelf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+int main(int argc, const char **argv)
+{
+ int fd;
+ Elf *elf;
+ size_t phnum;
+
+ if (argc != 2)
+ {
+ fprintf(stderr, "usage: %s FILE\n", argv[0]);
+ return EXIT_FAILURE;
+ }
+
+ fd = open(argv[1], O_RDONLY);
+ if (fd == -1)
+ {
+ perror("open");
+ return EXIT_FAILURE;
+ }
+ elf_version(EV_CURRENT);
+ elf = elf_begin(fd, ELF_C_READ, NULL);
+ if (!elf)
+ {
+ fprintf(stderr, "elf_begin: %s\n", elf_errmsg(-1));
+ return EXIT_FAILURE;
+ }
+ if (elf_getphdrnum(elf, &phnum))
+ {
+ fprintf(stderr, "elf_getphdrnum: %s\n", elf_errmsg(-1));
+ return EXIT_FAILURE;
+ }
+
+ printf("%zu\n", phnum);
+ return EXIT_SUCCESS;
+}
diff --git a/tests/run-getphdrnum.sh b/tests/run-getphdrnum.sh
new file mode 100755
index 00000000..889cdaf1
--- /dev/null
+++ b/tests/run-getphdrnum.sh
@@ -0,0 +1,137 @@
+#! /bin/sh
+
+# testfile-phdrs.elf generated with python3 script
+# import struct
+# import sys
+#
+# phnum = 66000
+#
+# sys.stdout.buffer.write(
+# struct.pack(
+# "<16BHHIQQQIHHHHHH",
+# # EI_MAG
+# *b"\x7fELF",
+# # EI_CLASS = ELFCLASS64
+# 2,
+# # EI_DATA = ELFDATA2LSB
+# 1,
+# # EI_VERSION
+# 1,
+# # EI_OSABI = ELFOSABI_SYSV
+# 0,
+# # EI_ABIVERSION
+# 0,
+# # EI_PAD
+# *bytes(7),
+# # e_type = ET_CORE
+# 4,
+# # e_machine = EM_X86_64
+# 62,
+# # e_version
+# 1,
+# # e_entry
+# 0,
+# # e_phoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Shdr)
+# 128,
+# # e_shoff = sizeof(Elf64_Ehdr)
+# 64,
+# # e_flags
+# 0,
+# # e_ehsize
+# 64,
+# # e_phentsize
+# 56,
+# # e_phnum = PN_XNUM
+# 0xFFFF,
+# # e_shentsize
+# 64,
+# # e_shnum
+# 1,
+# # e_shstrndx
+# 0,
+# )
+# )
+#
+# sys.stdout.buffer.write(
+# struct.pack(
+# "<IIQQQQIIQQ",
+# # sh_name
+# 0,
+# # sh_type = SHT_NULL
+# 0,
+# # sh_flags
+# 0,
+# # sh_addr
+# 0,
+# # sh_offset
+# 0,
+# # sh_size
+# 0,
+# # sh_link
+# 0,
+# # sh_info
+# phnum,
+# # sh_addralign
+# 0,
+# # sh_entsize
+# 0,
+# )
+# )
+#
+# for i in range(phnum):
+# sys.stdout.buffer.write(
+# struct.pack(
+# "<IIQQQQQQ",
+# # p_type = PT_LOAD
+# 1,
+# # p_flags = PF_X|PF_W|PF_R
+# 0x7,
+# # p_offset
+# 0,
+# # p_vaddr
+# # i * 4096,
+# 4096,
+# # p_paddr
+# 0,
+# # p_filesz
+# 0,
+# # p_memsz
+# 4096,
+# # p_align
+# 0,
+# )
+# )
+
+. $srcdir/test-subr.sh
+
+testfiles testfile-phdrs.elf
+
+testrun_compare ${abs_top_builddir}/src/readelf -h testfile-phdrs.elf<<\EOF
+ELF Header:
+ Magic: 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00
+ Class: ELF64
+ Data: 2's complement, little endian
+ Ident Version: 1 (current)
+ OS/ABI: UNIX - System V
+ ABI Version: 0
+ Type: CORE (Core file)
+ Machine: AMD x86-64
+ Version: 1 (current)
+ Entry point address: 0
+ Start of program headers: 128 (bytes into file)
+ Start of section headers: 64 (bytes into file)
+ Flags:
+ Size of this header: 64 (bytes)
+ Size of program header entries: 56 (bytes)
+ Number of program headers entries: 65535 (66000 in [0].sh_info)
+ Size of section header entries: 64 (bytes)
+ Number of section headers entries: 1
+ Section header string table index: 0
+
+EOF
+
+testrun_compare ${abs_builddir}/getphdrnum testfile-phdrs.elf<<\EOF
+66000
+EOF
+
+exit 0
diff --git a/tests/testfile-phdrs.elf.bz2 b/tests/testfile-phdrs.elf.bz2
new file mode 100644
index 0000000000000000000000000000000000000000..024ed79de1632f4e82daf9fb25d7bd4fb2680c05
GIT binary patch
literal 188
zcmV;t07L&mT4*^jL0KkKS>yw)-v-^p{KEdyNB{r`06{|p006)MKmY&$umHG3AQ}MB
zdW8TOjWp4qnx!Q4CX8eUtv1ebPzwK2fL56$0Ib%@C<SCHK`Pr_5hw*`?%MulcI>49
zukU_!?~0-XZlwUN<e(LzC=ASrLVywCDf1K+l4UiU#j@ofIy1fi1`Py&0ssdDFab)9
q2Gj&D$^sTB2w5Q%pz45ysvx2@<pB%I0v0F;Ul(#kI8cyuTy^czheuBU
literal 0
HcmV?d00001
--
2.18.2
