Commit Graph

16 Commits

Author SHA1 Message Date
Vasily Gorbik
0c4f2623b9 s390: setup kernel memory layout early
Currently there are two separate places where kernel memory layout has
to be known and adjusted:
1. early kasan setup.
2. paging setup later.

Those 2 places had to be kept in sync and adjusted to reflect peculiar
technical details of one another. With additional factors which influence
kernel memory layout like ultravisor secure storage limit, complexity
of keeping two things in sync grew up even more.

Besides that if we look forward towards creating identity mapping and
enabling DAT before jumping into uncompressed kernel - that would also
require full knowledge of and control over kernel memory layout.

So, de-duplicate and move kernel memory layout setup logic into
the decompressor.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-06-18 16:41:19 +02:00
Vasily Gorbik
8977ab65b8 s390/decompressor: add stacktrace support
Decompressor works on a single statically allocated stack. Stacktrace
implementation with -mbackchain just takes few lines of code.

Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c)
      R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a62c
      000000000000bf60 0000000000000000 00000000000003c0 0000000000000000
      0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018
      000000000311c000 0000000000010070 0000000000012f82 000000000000bea8
Call Trace:
(sp:000000000000bea8 [<000000000002016e>] 000000000002016e)
 sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc
 sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
9a78c70a1b s390/decompressor: add decompressor_printk
The decompressor does not have any special debug means. Running the
kernel under qemu with gdb is helpful but tedious exercise if done
repeatedly. It is also not applicable to debugging under LPAR and z/VM.

One special thing which stands out is a working sclp_early_printk,
which could be used once the kernel switches to 64-bit addressing mode.

But sclp_early_printk does not provide any string formating capabilities.
Formatting and printing string without printk-alike function is a
not fun. The lack of printk-alike function means people would save up on
testing and introduce more bugs.

So, finally, provide decompressor_printk function, which fits on one
screen and trades features for simplicity.

It only supports "%s", "%x" and "%lx" specifiers and zero padding for
hex values.

Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:11 +01:00
Vasily Gorbik
73045a08cf s390: unify identity mapping limits handling
Currently we have to consider too many different values which
in the end only affect identity mapping size. These are:
1. max_physmem_end - end of physical memory online or standby.
   Always <= end of the last online memory block (get_mem_detect_end()).
2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
   kernel is able to support.
3. "mem=" kernel command line option which limits physical memory usage.
4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as
   crash kernel.
5. "hsa" size which is a memory limit when the kernel is executed during
   zfcp/nvme dump.

Through out kernel startup and run we juggle all those values at once
but that does not bring any amusement, only confusion and complexity.

Unify all those values to a single one we should really care, that is
our identity mapping size.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-20 19:19:10 +01:00
Heiko Carstens
90178c1900 s390/mm: let vmalloc area size depend on physical memory size
To make sure that the vmalloc area size is for almost all cases large
enough let it depend on the (potential) physical memory size. There is
still the possibility to override this with the vmalloc kernel command
line parameter.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-11-09 11:20:59 +01:00
Linus Torvalds
d590284419 s390 updates for the 5.4 merge window
- Add support for IBM z15 machines.
 
 - Add SHA3 and CCA AES cipher key support in zcrypt and pkey refactoring.
 
 - Move to arch_stack_walk infrastructure for the stack unwinder.
 
 - Various kasan fixes and improvements.
 
 - Various command line parsing fixes.
 
 - Improve decompressor phase debuggability.
 
 - Lift no bss usage restriction for the early code.
 
 - Use refcount_t for reference counters for couple of places in
   mm code.
 
 - Logging improvements and return code fix in vfio-ccw code.
 
 - Couple of zpci fixes and minor refactoring.
 
 - Remove some outdated documentation.
 
 - Fix secure boot detection.
 
 - Other various minor code clean ups.
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Merge tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for IBM z15 machines.

 - Add SHA3 and CCA AES cipher key support in zcrypt and pkey
   refactoring.

 - Move to arch_stack_walk infrastructure for the stack unwinder.

 - Various kasan fixes and improvements.

 - Various command line parsing fixes.

 - Improve decompressor phase debuggability.

 - Lift no bss usage restriction for the early code.

 - Use refcount_t for reference counters for couple of places in mm
   code.

 - Logging improvements and return code fix in vfio-ccw code.

 - Couple of zpci fixes and minor refactoring.

 - Remove some outdated documentation.

 - Fix secure boot detection.

 - Other various minor code clean ups.

* tag 's390-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
  s390: remove pointless drivers-y in drivers/s390/Makefile
  s390/cpum_sf: Fix line length and format string
  s390/pci: fix MSI message data
  s390: add support for IBM z15 machines
  s390/crypto: Support for SHA3 via CPACF (MSA6)
  s390/startup: add pgm check info printing
  s390/crypto: xts-aes-s390 fix extra run-time crypto self tests finding
  vfio-ccw: fix error return code in vfio_ccw_sch_init()
  s390: vfio-ap: fix warning reset not completed
  s390/base: remove unused s390_base_mcck_handler
  s390/sclp: Fix bit checked for has_sipl
  s390/zcrypt: fix wrong handling of cca cipher keygenflags
  s390/kasan: add kdump support
  s390/setup: avoid using strncmp with hardcoded length
  s390/sclp: avoid using strncmp with hardcoded length
  s390/module: avoid using strncmp with hardcoded length
  s390/pci: avoid using strncmp with hardcoded length
  s390/kaslr: reserve memory for kasan usage
  s390/mem_detect: provide single get_mem_detect_end
  s390/cmma: reuse kstrtobool for option value parsing
  ...
2019-09-17 14:04:43 -07:00
Vasily Gorbik
724dc336b7 s390/startup: add pgm check info printing
Try to print out startup pgm check info including exact linux kernel
version, pgm interruption code and ilc, psw and general registers. Like
the following:

Linux version 5.3.0-rc7-07282-ge7b4d41d61bd-dirty (gor@tuxmaker) #3 SMP PREEMPT Thu Sep 5 16:07:34 CEST 2019
Kernel fault: interruption code 0005 ilc:2
PSW : 0000000180000000 0000000000012e52
      R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3
GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 0000000000019a58
      000000000000bf68 0000000000000000 0000000000000000 0000000000000000
      0000000000000000 0000000000000000 000000000001a041 0000000000000000
      0000000004c9c000 0000000000010070 0000000000012e42 000000000000beb0

This info makes it apparent that kernel startup failed and might help
to understand what went wrong without actual standalone dump.

Printing code runs on its own stack of 1 page (at unused 0x5000), which
should be sufficient for sclp_early_printk usage (typical stack usage
observed has been around 512 bytes).

The code has pgm check recursion prevention, despite pgm check info
printing failure (follow on pgm check) or success it restores original
faulty psw and gprs and does disabled wait.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-09-13 12:17:37 +02:00
Vasily Gorbik
868202ce15 s390/boot: add missing declarations and includes
Add __swsusp_reset_dma declaration to avoid the following sparse warnings:
arch/s390/kernel/setup.c:107:15: warning: symbol '__swsusp_reset_dma' was not declared. Should it be static?
arch/s390/boot/startup.c:52:15: warning: symbol '__swsusp_reset_dma' was not declared. Should it be static?

Add verify_facilities declaration to avoid the following sparse warning:
arch/s390/boot/als.c:105:6: warning: symbol 'verify_facilities' was not declared. Should it be static?

Include "boot.h" into arch/s390/boot/kaslr.c to expose get_random_base
function declaration and avoid the following sparse warning:
arch/s390/boot/kaslr.c:90:15: warning: symbol 'get_random_base' was not declared. Should it be static?

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-07-29 18:05:02 +02:00
Vasily Gorbik
6abe281970 s390: enable detection of kernel version from bzImage
Extend "parmarea" to include an offset of the version string, which is
stored as 8-byte big endian value.

To retrieve version string from bzImage reliably, one should check the
presence of "S390EP" ascii string at 0x10008 (available since v3.2),
then read the version string offset from 0x10428 (which has been 0
since v3.2 up to now). The string is null terminated.

Could be retrieved with the following "file" command magic (requires
file v5.34):
8 string \x02\x00\x00\x18\x60\x00\x00\x50\x02\x00\x00\x68\x60\x00\x00\x50\x40\x40\x40\x40\x40\x40\x40\x40 Linux S390
>0x10008       string          S390EP
>>0x10428      bequad          >0
>>>(0x10428.Q) string          >\0             \b, version %s

Reported-by: Petr Tesarik <ptesarik@suse.com>
Suggested-by: Petr Tesarik <ptesarik@suse.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-07-23 10:43:50 +02:00
Gerald Schaefer
b2d24b97b2 s390/kernel: add support for kernel address space layout randomization (KASLR)
This patch adds support for relocating the kernel to a random address.
The random kernel offset is obtained from cpacf, using either TRNG, PRNO,
or KMC_PRNG, depending on supported MSA level.

KERNELOFFSET is added to vmcoreinfo, for crash --kaslr support.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29 10:47:10 +02:00
Martin Schwidefsky
9641b8cc73 s390/ipl: read IPL report at early boot
Read the IPL Report block provided by secure-boot, add the entries
of the certificate list to the system key ring and print the list
of components.

PR: Adjust to Vasilys bootdata_preserved patch set. Preserve ipl_cert_list
for later use in kexec_file.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26 12:34:05 +02:00
Vasily Gorbik
6d85dac2ab s390: warn about clearing als implied facilities
Add a warning about removing required architecture level set facilities
via "facilities=" command line option.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-01 08:00:42 +01:00
Vasily Gorbik
b5e804598d s390: allow overriding facilities via command line
Add "facilities=" command line option which allows to override
facility bits returned by stfle. The main purpose of that is debugging
aids which allows to test specific kernel behaviour depending on
specific facilities presence. It also affects CPU alternatives.

"facilities=" command line option format is comma separated list of
integer values to be additionally set or cleared (if value is starting
with "!"). Values ranges are also supported. e.g.:

facilities=!130-160,159,167-169

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-01 08:00:41 +01:00
Vasily Gorbik
49698745e5 s390: move ipl block and cmd line handling to early boot phase
To distinguish zfcpdump case and to be able to parse some of the kernel
command line arguments early (e.g. mem=) ipl block retrieval and command
line construction code is moved to the early boot phase.

"memory_end" is set up correctly respecting "mem=" and hsa_size in case
of the zfcpdump.

arch/s390/boot/string.c is introduced to provide string handling and
command line parsing functions to early boot phase code for the compressed
kernel image case.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:21:14 +02:00
Vasily Gorbik
6966d604e2 s390/mem_detect: move tprot loop to early boot phase
Move memory detection to early boot phase. To store online memory
regions "struct mem_detect_info" has been introduced together with
for_each_mem_detect_block iterator. mem_detect_info is later converted
to memblock.

Also introduces sclp_early_get_meminfo function to get maximum physical
memory and maximum increment number.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:21:08 +02:00
Vasily Gorbik
8f75582a2f s390: remove decompressor's head.S
Decompressor's head.S provided "data mover" sole purpose of which has
been to safely move uncompressed kernel at 0x100000 and jump to it.

With current bzImage layout entire decompressor's code guaranteed to be
in a safe location under 0x100000, and hence could not be overwritten
during kernel move. For that reason head.S could be replaced with simple
memmove function. To do so introduce early boot code phase which is
executed from arch/s390/boot/head.S after "verify_facilities" and takes
care of optional kernel image decompression and transition to it.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:21:02 +02:00