So far powerpc kernel never exported memory limit information which is
reflected by mem= kernel cmdline option. Hence, kexec-tools always use
to build ELF header for entire system RAM generating a dump bigger than
the actual memory used by the first kernel.
The following upstream kernel commits now exports memory limit information
through /proc/device-tree file:
4bc77a5ed - powerpc: Export memory limit via device tree
a84fcd468 - powerpc: Change memory_limit from phys_addr_t to unsigned
long long
This patch series now reads the memory limit information from
device-tree file if present and limits the crash memory ranges accordingly.
Tested these patches on ppc32(ppc440) and ppc64 with a kernel patch by Suzuki.
Changes in v2:
- Fixed few formatting and coding style issues.
- Fixed error handling path and possible buffer overflow issue in patch 1/2.
- Fixed an issue where an additional PT_LOAD section, representing zero size
memory segment (with start address == memory_limit), was getting added to ELF
section.
Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
Tested-by: Suzuki K. Poulose <suzuki at in.ibm.com>
---
Mahesh Salgaonkar (2):
kexec: Respect memory limit while building crash memory ranges on ppc32.
kexec: Respect memory limit while building crash memory ranges on ppc64
kexec/arch/ppc/crashdump-powerpc.c | 14 ++++++++--
kexec/arch/ppc/crashdump-powerpc.h | 1 +
kexec/arch/ppc/kexec-ppc.c | 51 ++++++++++++++++++++++++++++++++++++
kexec/arch/ppc64/crashdump-ppc64.c | 11 +++++++-
kexec/arch/ppc64/crashdump-ppc64.h | 1 +
kexec/arch/ppc64/kexec-ppc64.c | 27 +++++++++++++++++++
6 files changed, 101 insertions(+), 4 deletions(-)
--
-Mahesh
