Since linux v3.14 with commit 38dfac843c ("vmcore: prevent PT_NOTE
p_memsz overflow during header update") on s390 we get the following
message in the kdump kernel:
Warning: Exceeded p_memsz, dropping PT_NOTE entry n_namesz=0x6b6b6b6b,
n_descsz=0x6b6b6b6b
The reason for this is that we don't create a final zero note in
the ELF header which the proc/vmcore code uses to find out the end
of the notes section (see also kernel/kexec_core.c:final_note()).
It still worked on s390 by chance because we (most of the time?) have the
byte pattern 0x6b6b6b6b after the notes section which also makes the notes
parsing code stop in update_note_header_size_elf64() because 0x6b6b6b6b is
interpreded as note size:
if ((real_sz + sz) > max_sz) {
pr_warn("Warning: Exceeded p_memsz, dropping P ...);
break;
}
So fix this and add the missing final note to the ELF header.
We don't have to adjust the memory size for ELF header ("alloc_size")
because the new ELF note still fits into the 0x1000 base memory.
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Provide the name of each memblock type with struct memblock_type. This
allows to get rid of the function memblock_type_name() and duplicating
the type names in __memblock_dump_all().
The only memblock_type usage out of mm/memblock.c seems to be
arch/s390/kernel/crash_dump.c. While at it, give it a name.
Link: http://lkml.kernel.org/r/20170120123456.46508-4-heiko.carstens@de.ibm.com
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.
Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each change instance
for the presence of either and replace as needed. Build testing
revealed some implicit header usage that was fixed up accordingly.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In binutils/libbfd (bfd/elf.c) it is enforced that all s390 specific ELF
notes like e.g. NT_S390_PREFIX or NT_S390_CTRS have "LINUX" specified
as note name. Otherwise the notes are ignored.
For /proc/vmcore we currently use "CORE" for these notes.
Up to now this has not been a real problem because the dump analysis tool
"crash" does not check the note name. But it will break all programs that
use libbfd for processing ELF notes.
So fix this and use "LINUX" for all s390 specific notes to comply with
libbfd.
Cc: stable@vger.kernel.org # v4.4+
Reported-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The combo of list_empty() check and return list_first_entry()
can be replaced with list_first_entry_or_null().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
copy_oldmem_user() and ap_jumptable are private to the files they are
being used in. Therefore make them static.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
memblock_alloc() and memblock_alloc_base() will panic on their own if
they can't find free memory. Therefore remove some pointless checks.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Finally get rid of the leading underscore. I tried this already two or
three years ago, however Michael Holzheu objected since this would
break the crash utility (again).
However Michael integrated support for the new name into the crash
utility back then, so it doesn't break if the name will be changed
now. So finally get rid of the ever confusing leading underscore.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce save_area_alloc(), save_area_boot_cpu(), save_area_add_regs()
and save_area_add_vxrs to deal with storing the CPU state in case of a
system dump. Remove struct save_area and save_area_ext, and create a new
struct save_area as a local definition to arch/s390/kernel/crash_dump.c.
Copy each individual field from the hardware status area to the save area,
storing the minimum of required data.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce two copy functions for the memory of the dumped system,
copy_oldmem_kernel() to copy to the virtual kernel address space
and copy_oldmem_user() to copy to user space.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The s390 architecture can store the CPU registers of the crashed system
after the kdump kernel has been started and this is the preferred way.
Remove the remaining code fragments that deal with storing CPU registers
while the crashed system is still active.
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The <linux/memblock.h> already provides for_each_mem_range() macro that
iterates through memblock areas from type_a and not included in type_b.
We can remove custom for_each_dump_mem_range() macro and use the
for_each_mem_range() instead.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
It turned out that SIGP set-multi-threading can only be done once.
Therefore switching to a different MT level after switching to
sclp.mtid_prev in the dump case fails.
As a symptom specifying the "nosmt" parameter currently fails for
the kdump kernel and the kernel starts with multi-threading enabled.
So fix this and issue diag 308 subcode 1 call after collecting the
CPU states for the dump. Also enhance the diag308_reset() function to
be usable also with enabled lowcore protection and prefix register != 0.
After the reset it is possible to switch the MT level again. We have
to do the reset very early in order not to kill the already initialized
console. Therefore instead of kmalloc() the corresponding memblock
functions have to be used. To avoid copying the sclp cpu code into
sclp_early, we now use the simple sigp loop method for CPU detection.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The REGSET_VX_LOW ELF notes should contain the lower 64 bit halfes of the
first sixteen 128 bit vector registers. Unfortunately currently we copy
the upper halfes.
Fix this and correctly copy the lower halfes.
Fixes: a62bc07392 ("s390/kdump: add support for vector extension")
Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Some high end Intel Xeon systems report uncorrectable memory errors as a
recoverable machine check. Linux has included code for some time to
process these and just signal the affected processes (or even recover
completely if the error was in a read only page that can be replaced by
reading from disk).
But we have no recovery path for errors encountered during kernel code
execution. Except for some very specific cases were are unlikely to ever
be able to recover.
Enter memory mirroring. Actually 3rd generation of memory mirroing.
Gen1: All memory is mirrored
Pro: No s/w enabling - h/w just gets good data from other side of the
mirror
Con: Halves effective memory capacity available to OS/applications
Gen2: Partial memory mirror - just mirror memory begind some memory controllers
Pro: Keep more of the capacity
Con: Nightmare to enable. Have to choose between allocating from
mirrored memory for safety vs. NUMA local memory for performance
Gen3: Address range partial memory mirror - some mirror on each memory
controller
Pro: Can tune the amount of mirror and keep NUMA performance
Con: I have to write memory management code to implement
The current plan is just to use mirrored memory for kernel allocations.
This has been broken into two phases:
1) This patch series - find the mirrored memory, use it for boot time
allocations
2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the
unused mirrored memory from mm/memblock.c and only give it out to
select kernel allocations (this is still being scoped because
page_alloc.c is scary).
This patch (of 3):
Add extra "flags" to memblock to allow selection of memory based on
attribute. No functional changes
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Xiexiuqi <xiexiuqi@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's unify basic access to sclp fields by storing the data in an external
struct in asm/sclp.h.
The values can now directly be accessed by other components, so there is
no need for most accessor functions and external variables anymore.
The mtid, mtid_max and facility part will be cleaned up separately.
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With this patch for kdump the s390 vector registers are stored into the
prepared save areas in the old kernel and into the REGSET_VX_LOW and
REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel.
The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector
registers 0-15. The higher halves are stored in the floating point register
ELF note. The NT_S390_VXRS_HIGH contains the full vector registers 16-31.
The kernel provides a save area for storing vector register in case of
machine checks. A pointer to this save are is stored in the CPU lowcore
at offset 0x11b0. This save area is also used to save the registers for
kdump. In case of a dumped crashed kdump those areas are used to extract
the registers of the production system.
The vector registers for remote CPUs are stored using the "store additional
status at address" SIGP. For the dump CPU the vector registers are stored
with the VSTM instruction.
With this patch also zfcpdump stores the vector registers.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The original bootmem allocator is getting replaced by memblock. To
cover the needs of the s390 kdump implementation the physical memory
list is used.
With this patch the bootmem allocator and its bitmaps are completely
removed from s390.
Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently we have hardcoded the HSA size to 32 MiB. With this patch the
HSA size is determined dynamically via SCLP in early.c.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently zfpcdump can only collect registers for up to CONFIG_NR_CPUS
CPUss. This dependency is not necessary. So remove it by dynamically
allocating the save area array.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Get rid of this compile warning:
arch/s390/kernel/crash_dump.c: In function 'copy_from_realmem':
arch/s390/kernel/crash_dump.c:48:6: warning: unused variable 'rc'
[-Wunused-variable]
int rc;
^
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently copy_from_oldmem() is not able to copy to virtual memory.
When using kexec pre-allocated ELF header, copy_from_oldmem()
is used to copy the ELF notes information to vmalloc buffers.
So fix this and use the new function copy_from_realmem() that allows
copying also to vmalloc memory.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Modify the s390 copy_oldmem_page() and remap_oldmem_pfn_range() function
for zfcpdump to read from the HSA memory if memory below HSA_SIZE bytes is
requested. Otherwise real memory is used.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce the s390 specific way to map pages from oldmem. The memory area
below OLDMEM_SIZE is mapped with offset OLDMEM_BASE. The other old memory
is mapped directly.
Signed-off-by: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Exchange the old relocate mechanism with the new arch function call
override mechanism that allows to create the ELF core header in the 2nd
kernel.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kdump mmap patch series (git commit 83086978c6) changed the
requirements for copy_oldmem_page(). Now this function is used for copying
to virtual memory.
So implement vmalloc support for the s390 version of copy_oldmem_page().
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Simplify the memory detection code a bit by removing the CHUNK_OLDMEM
and CHUNK_CRASHK memory types.
They are not needed. Everything that is needed is a mechanism to
insert holes into the detected memory.
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The current memory detection loop will detect all present memory of
a machine. This is true even if the user specified the "mem=" parameter
on the kernel command line.
This can be a problem since the memory detection may cause a fully
populated host page table for the guest, even for those parts of the
memory that the guest will never use afterwards.
So fix this and only detect memory up to a user supplied "mem=" limit
if specified.
Reported-by: Michael Johanssen <johanssn@de.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Move fill_cpu_elf_notes() prototype to header file.
This way we get compile errors if e.g. the number of function
parameters get changed.
Otherwise it's possible to change just the definition and everything
else still compiles fine, but the result is broken code.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In order to allow kdump based stand-alone dump, some information
has to be passed from the old kernel to the new dump kernel. This
is done via a the struct "os_info" that contains the following fields:
* crashkernel base and size
* reipl block
* vmcoreinfo
* init function
A pointer to os_info is stored at a well known storage location
and the whole structure as well as all fields are secured with
checksums.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/kernel/crash_dump.c included 'linux/crash_dump.h' twice,
remove the duplicate.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently it can happen that the pre-allocated ELF header contains a wrong
memory map which would result in errors when copying /proc/vmcore.
In order to still get a valid vmcore, we (temporarily) disable the error
checking in copy_oldmem_page(). This will then produce zero pages for those
memory regions.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch provides the architecture specific part of the s390 kdump
support.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
