The keyword extern before a function declaration is not required with
modern C compilers.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The primary goal of this change is to split DFO ELF module into
multiple smaller ones for better unit testability.
The change doesn't introduce any functionality changes, just shuffling code
around.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The primary goal is to separate DFO code into multiple smaller modules
and make it unit testable.
This refactoring only moved the code around w/o changing any functionality.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
...to make clear why `off` is initialized to 0 and that all calls to
`dfo_chunk_add` occur for the same reason. For consistency reasons adapt
the `off` value calculation as well.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Rename the parameter `ptr` of `notes_init` to something meaningful. Since
it points to the start of the notes segment rename it to `segment_start`.
In addition, improve the documentation for the function.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Use `mem_chunk->size` instead of recalculate it. In addition, assign
`p_vaddr` to `p_paddr` to make clear that they must be equal and rename the
parameter `load_offset` to `elf_offset` to make clear that the offset in
the ELF vmcore file is meant. Finally rename `loads_init` to
`load_phdrs_init`.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This cast makes the macros easier to use without getting compiler warnings.
e.g.
dfo_elf.c: In function 'dfo_elf_init':
dfo_elf.c:343:20: warning: assignment to 'Elf64_Phdr *' from incompatible pointer type 'char *' [-Wincompatible-pointer-types]
343 | phdrs_load = PTR_ADD(phdr_notes, sizeof(Elf64_Phdr) * phdrs_notes_count);
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
With an upcoming patch the output target can be different to `stdout`.
Therefore, the term `ZG_ACTION_STDOUT` is no longer generic enough. In addition,
rename `do_write` to `do_copy` to match the enum name.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Currently, for some commands (e.g. `zgetdump unmount`) unused positional
arguments are silently ignored, for some commands (`zgetdump mount`) they're
not. Therefore let's fix this by always returning an error message and exit code
if too many positional arguments are given.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Don't include dfi_mem_chunk.h in dfi.h because not every module including
dfi.h needs it.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Separate the definition of a struct from the declaration of a global
variable of the type. To improve readability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for STDOUT to separate independent things and
make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Set DFO format after the parsing of command-line arguments is done.
The command-line argument parsing should be independent of DFO.
This improves testability of the command-line argument parsing and
separates independent things from each other.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Make the C module responsible for the parsing of command-line arguments
independent of other global variables. This improves its testability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Get rid of C headers which include everything. This is bad for testing and
maintainability. C files should include only what they need and no more.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for FUSE to separate independent things and
make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for DFI VMCOREINFO to separate
independent things and make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Replace magic values with descriptive names to improve readability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
To prevent segmentation faults when the function dfi_mem_phys_read() is
given invalid parameters, check that the given memory range falls within
a known physical memory chunk, just like it is done for dfi_mem_virt_read().
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The new name describes the purpose of the function better and
emphasizes its difference with the function dfi_mem_phys_read().
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Always use the function dfi_mem_read_rc() which verifies that the given
address and size fall within a valid memory chunk. We cannot trust
user's input.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The function dfi_mem_chunk_virt_add() is used only internally and should
not be exported to prevent misuse.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The keyword extern is redundant for function declarations in C headers.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
zgetdump is for analyzing VM coredumps and not user space coredumps therefore
return an error in case of a user space coredump.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This fixes the following Valgrind finding:
==28040== Syscall param rt_sigaction(act->sa_flags) points to uninitialised byte(s)
==28040== at 0x48C98B0: __libc_sigaction (sigaction.c:58)
==28040== by 0x10D507: sig_handler_init (zgetdump.c:58)
==28040== by 0x10D507: main (zgetdump.c:179)
==28040== Address 0x1ffefffc84 is on thread 1's stack
==28040== in frame #0, created by __libc_sigaction (sigaction.c:43)
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Sanity check ELF notes descriptor size before reading it. This prevents
stack buffer overflows in case a dump contains invalid ELF notes.
Instead of reading a note's descriptor into a temporary buffer on stack,
read it directly into the buffer given to nt_read() but also provide
a maximum length of the given buffer to nt_read() in order to prevent
overflows.
This problem was found with valgrind and AFL fuzzing + ASAN.
AFL + ASAN findings:
[root@t83lp49 s390-tools]# ./zdump/zgetdump -iVVVVV ~/zgetdump-fuzzing/findings/crashes/id\:000008\,sig\:06\,src\:000007\,op\:arith8\,pos\:67\,val\:+3
TRACE: DFI initialization
DEBUG: DFI trying s390tape
DEBUG: DFI s390tape returned with rc -19
DEBUG: DFI trying devmem
DEBUG: DFI devmem returned with rc -19
DEBUG: DFI trying s390mv_ext
DEBUG: DFI s390mv_ext returned with rc -19
DEBUG: DFI trying s390mv
DEBUG: DFI s390mv returned with rc -19
DEBUG: DFI trying s390_ext
DEBUG: DFI S390 extended initialization
DEBUG: DFI s390_ext returned with rc -19
DEBUG: DFI trying s390
DEBUG: DFI S390 initialization
DEBUG: DFI s390 returned with rc -19
DEBUG: DFI trying lkcd
DEBUG: DFI lkcd returned with rc -19
DEBUG: DFI trying elf
DEBUG: DFI ELF initialization
DEBUG: DFI ELF e_phnum 11
DEBUG: DFI ELF p_type[0] 0x4
DEBUG: DFI ELF n_type 0x0
AddressSanitizer:DEADLYSIGNAL
=================================================================
==208548==ERROR: AddressSanitizer: stack-overflow on address 0x03ffef05d000 (pc 0x0000010051b0 bp 0x03fff107dc40 sp 0x03ffef05dac8 T0)
#0 0x10051b0 (/root/s390-tools/zdump/zgetdump+0x10051b0)
SUMMARY: AddressSanitizer: stack-overflow (/root/s390-tools/zdump/zgetdump+0x10051b0)
==208548==ABORTING
valgrind findings:
==56423== Source and destination overlap in memcpy(0x4a86d38, 0x4a875e0, 4096)
==56423== at 0x4839F86: memcpy (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x114253: memcpy (string_fortified.h:34)
==56423== by 0x114253: nt_read (dfi_elf.c:95)
==56423== by 0x1145FF: nt_s390_prefix_read (dfi_elf.c:195)
==56423== by 0x1145FF: pt_notes_add (dfi_elf.c:259)
==56423== by 0x1145FF: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
==56423==
==56423== Invalid write of size 8
==56423== at 0x4839E28: memcpy (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x114253: memcpy (string_fortified.h:34)
==56423== by 0x114253: nt_read (dfi_elf.c:95)
==56423== by 0x1145FF: nt_s390_prefix_read (dfi_elf.c:195)
==56423== by 0x1145FF: pt_notes_add (dfi_elf.c:259)
==56423== by 0x1145FF: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
==56423== Address 0x4a86ee0 is 0 bytes after a block of size 912 alloc'd
==56423== at 0x483675E: calloc (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x10E71D: zg_alloc (zg.c:93)
==56423== by 0x114793: nt_prstatus_read (dfi_elf.c:123)
==56423== by 0x114793: pt_notes_add (dfi_elf.c:234)
==56423== by 0x114793: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
If the while loop in mem_chunks_add_ext() is never executed, then
the stack variable containing the dump segment header will never be
initialized.
clang's static code analyzer reports the following problem:
$ make CC="clang --analyze" -C zdump
dfi_s390.c:157:6: warning: Branch condition evaluates to a garbage value [core.uninitialized.Branch]
if (!dump_segm.stop_marker)
^~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Use util_log from libutil to output various log messages that can be helpful
during problem analysis.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Replace the incorrect %d format specifier with %u one for unsigned integer
types.
This issue was found with AFL fuzzing.
$ ./zdump/zgetdump -i ~/input.bin
General dump info:
Dump format........: s390
Version............: -2147483647
System arch........: s390x (64 bit)
CPU count (online).: 32768
Dump memory range..: 1 MB
Memory map:
0000000000000000 - 00000000000f423f (1 MB)
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Before reading data in dfi_vmcoreinfo_init(), check the validity
of the memory range. Otherwise this can result in a segmentation fault when
zgetdump is given a very small dump, e.g. S390 DASD single-volume dump of
size 0x10 bytes.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Before reading data in os_info_get(), check the validity of the memory
range. Otherwise this can result in a segmentation fault when zgetdump is
given a very small dump, e.g. S390 DASD single-volume dump of size 0x10
bytes.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Before reading data at addresses 0x10418 and 0x10420 in kdump_init(),
validate the validity of the memory range. Otherwise this can result in
a segmentation fault when zgetdump is given a very small dump, e.g.
S390 DASD single-volume dump of size 0x1000 bytes.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The dfi_vmcoreinfo_init() function might be called on a dump of a non-ELF
format because the DFI goes through all supported dump formats when first
trying to identify of what dump format the given input is. Therefore,
we must be very careful in interpreting read data and ensure that it
makes sense before accessing or using it.
This commit prevents a potential overflow of a stack buffer in
dfi_vmcoreinfo_init() if note.n_namesz is bigger than the stack buffer.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The function mem_chunks_add_ext() allocates but does not release memory
if it encounters unexpected errors during dump segment reading.
Allocate memory passed to dfi_mem_chunk_add() right before calling
the function. This way there is no need for a cleanup anymore.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Alexander Egorenkov