linux.git/arch/powerpc/kernel/fadump.c, branch v5.4.211

powerpc/fadump: fix PT_LOAD segment for boot memory area

2022-06-14T16:11:40+00:00

[ Upstream commit 15eb77f873255cf9f4d703b63cfbd23c46579654 ]

Boot memory area is setup as separate PT_LOAD segment in the vmcore
as it is moved by f/w, on crash, to a destination address provided by
the kernel. Having separate PT_LOAD segment helps in handling the
different physical address and offset for boot memory area in the
vmcore.

Commit ced1bf52f477 ("powerpc/fadump: merge adjacent memory ranges to
reduce PT_LOAD segements") inadvertly broke this pre-condition for
cases where some of the first kernel memory is available adjacent to
boot memory area. This scenario is rare but possible when memory for
fadump could not be reserved adjacent to boot memory area owing to
memory hole or such. Reading memory from a vmcore exported in such
scenario provides incorrect data.  Fix it by ensuring no other region
is folded into boot memory area.

Fixes: ced1bf52f477 ("powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements")
Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220406093839.206608-2-hbathini@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/fadump: Mark fadump_calculate_reserve_size as __init

2021-05-14T07:44:26+00:00

[ Upstream commit fbced1546eaaab57a32e56c974ea8acf10c6abd8 ]

If fadump_calculate_reserve_size() is not inlined, there is a modpost
warning:

WARNING: modpost: vmlinux.o(.text+0x5196c): Section mismatch in
reference from the function fadump_calculate_reserve_size() to the
function .init.text:parse_crashkernel()
The function fadump_calculate_reserve_size() references
the function __init parse_crashkernel().
This is often because fadump_calculate_reserve_size lacks a __init
annotation or the annotation of parse_crashkernel is wrong.

fadump_calculate_reserve_size() calls parse_crashkernel(), which is
marked as __init and fadump_calculate_reserve_size() is called from
within fadump_reserve_mem(), which is also marked as __init.

Mark fadump_calculate_reserve_size() as __init to fix the section
mismatch. Additionally, remove the inline keyword as it is not necessary
to inline this function; the compiler is still free to do so if it feels
it is worthwhile since commit 889b3c1245de ("compiler: remove
CONFIG_OPTIMIZE_INLINING entirely").

Fixes: 11550dc0a00b ("powerpc/fadump: reuse crashkernel parameter for fadump memory reservation")
Signed-off-by: Nathan Chancellor 
Signed-off-by: Michael Ellerman 
Link: https://github.com/ClangBuiltLinux/linux/issues/1300
Link: https://lore.kernel.org/r/20210302195013.2626335-1-nathan@kernel.org
Signed-off-by: Sasha Levin

powerpc/fadump: Account for memory_limit while reserving memory

2020-06-22T07:31:22+00:00

commit 9a2921e5baca1d25eb8d21f21d1e90581a6d0f68 upstream.

If the memory chunk found for reserving memory overshoots the memory
limit imposed, do not proceed with reserving memory. Default behavior
was this until commit 140777a3d8df ("powerpc/fadump: consider reserved
ranges while reserving memory") changed it unwittingly.

Fixes: 140777a3d8df ("powerpc/fadump: consider reserved ranges while reserving memory")
Cc: stable@vger.kernel.org
Reported-by: kbuild test robot 
Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/159057266320.22331.6571453892066907320.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman

powerpc/fadump: consider reserved ranges while reserving memory

2020-06-22T07:31:21+00:00

commit 140777a3d8dfdb3d3f20ea7707c0f1c0ce1b0aa5 upstream.

Commit 0962e8004e97 ("powerpc/prom: Scan reserved-ranges node for
memory reservations") enabled support to parse reserved-ranges DT
node and reserve kernel memory falling in these ranges for F/W
purposes. Memory reserved for FADump should not overlap with these
ranges as it could corrupt memory meant for F/W or crash'ed kernel
memory to be exported as vmcore.

But since commit 579ca1a27675 ("powerpc/fadump: make use of memblock's
bottom up allocation mode"), memblock_find_in_range() is being used to
find the appropriate area to reserve memory for FADump, which can't
account for reserved-ranges as these ranges are reserved only after
FADump memory reservation.

With reserved-ranges now being populated during early boot, look out
for these memory ranges while reserving memory for FADump. Without
this change, MPIPL on PowerNV systems aborts with hostboot failure,
when memory reserved for FADump is less than 4096MB.

Fixes: 579ca1a27675 ("powerpc/fadump: make use of memblock's bottom up allocation mode")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini 
Reviewed-by: Mahesh Salgaonkar 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/158737297693.26700.16193820746269425424.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman

powerpc/fadump: use static allocation for reserved memory ranges

2020-06-22T07:31:21+00:00

commit 02c04e374e176ae3a3f64a682f80702f8d2fb65d upstream.

At times, memory ranges have to be looked up during early boot, when
kernel couldn't be initialized for dynamic memory allocation. In fact,
reserved-ranges look up is needed during FADump memory reservation.
Without accounting for reserved-ranges in reserving memory for FADump,
MPIPL boot fails with memory corruption issues. So, extend memory
ranges handling to support static allocation and populate reserved
memory ranges during early boot.

Fixes: dda9dbfeeb7a ("powerpc/fadump: consider reserved ranges while releasing memory")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini 
Reviewed-by: Mahesh Salgaonkar 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/158737294432.26700.4830263187856221314.stgit@hbathini.in.ibm.com
Signed-off-by: Greg Kroah-Hartman

powerpc/fadump: support holes in kernel boot memory area

2019-09-13T14:04:46+00:00

With support to copy multiple kernel boot memory regions owing to copy
size limitation, also handle holes in the memory area to be preserved.
Support as many as 128 kernel boot memory regions. This allows having
an adequate FADump capture kernel size for different scenarios.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/156821385448.5656.6124791213910877759.stgit@hbathini.in.ibm.com

powerpc/fadump: remove RMA_START and RMA_END macros

2019-09-13T14:04:46+00:00

RMA_START is defined as '0' and there is even a BUILD_BUG_ON() to
make sure it is never anything else. Remove this macro and use '0'
instead as code change is needed anyway when it has to be something
else. Also, remove unused RMA_END macro.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/156821384096.5656.15026984053970204652.stgit@hbathini.in.ibm.com

powerpc/fadump: consider f/w load area

2019-09-13T14:04:45+00:00

OPAL loads kernel & initrd at 512MB offset (256MB size), also exported
as ibm,opal/dump/fw-load-area. So, if boot memory size of FADump is
less than 768MB, kernel memory to be exported as '/proc/vmcore' would
be overwritten by f/w while loading kernel & initrd. To avoid such a
scenario, enforce a minimum boot memory size of 768MB on OPAL platform
and skip using FADump if a newer F/W version loads kernel & initrd
above 768MB.

Also, irrespective of RMA size, set the minimum boot memory size
expected on pseries platform at 320MB. This is to avoid inflating the
minimum memory requirements on systems with 512M/1024M RMA size.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/156821381414.5656.1592867278535469652.stgit@hbathini.in.ibm.com

powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel

2019-09-13T14:04:45+00:00

Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures
that crash data, from previously crash'ed kernel, is preserved. This
helps in cases where FADump is not enabled but the subsequent memory
preserving kernel boot is likely to process this crash data. One
typical usecase for this config option is petitboot kernel.

As OPAL allows registering address with it in the first kernel and
retrieving it after MPIPL, use it to store the top of boot memory.
A kernel that intends to preserve crash data retrieves it and avoids
using memory beyond this address.

Move arch_reserved_kernel_pages() function as it is needed for both
FA_DUMP and PRESERVE_FA_DUMP configurations.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/156821375751.5656.11459483669542541602.stgit@hbathini.in.ibm.com

powerpc/fadump: improve how crashed kernel's memory is reserved

2019-09-13T14:04:45+00:00

The size parameter to fadump_reserve_crash_area() function is not needed
as all the memory above boot memory size must be preserved anyway. Update
the function by dropping this redundant parameter.

Signed-off-by: Hari Bathini 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/156821374440.5656.2945512543806951766.stgit@hbathini.in.ibm.com