People reported kernel panic occurs during system boots up with mem boot option. After checking code, several problems are found about memmap= and mem= in boot stage kaslr.
*) In commit f28442497b5c ("x86/boot: Fix KASLR and memmap= collision"), only one memmap entry is considered and only the last one if multiple memmap entries are specified. *) mem= and memmap=nn[KMG] are not considered yet. They are used to limit max address of system. Kernel can't be randomized to be above the limit. *) kernel-parameters.txt doesn't tell the updated behaviour of memmap=. This patchset tries to solve above issues. Baoquan He (4): param: Move function next_arg to lib/cmdline.c for later reuse KASLR: Parse all memmap entries in cmdline KASLR: Handle memory limit specified by memmap and mem option doc: Update description about memmap option in kernel-parameter.txt Documentation/admin-guide/kernel-parameters.txt | 9 ++ arch/x86/boot/compressed/cmdline.c | 2 +- arch/x86/boot/compressed/kaslr.c | 161 ++++++++++++++---------- arch/x86/boot/string.c | 8 ++ include/linux/kernel.h | 1 + kernel/params.c | 52 -------- lib/cmdline.c | 57 +++++++++ 7 files changed, 172 insertions(+), 118 deletions(-) -- 2.5.5