On 04/18/17 at 02:51pm, Ingo Molnar wrote: > > * Baoquan He <[email protected]> wrote: > > > On 04/18/17 at 11:47am, Ingo Molnar wrote: > > > > > > * Baoquan He <[email protected]> wrote: > > > > > > > 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(-) > > > > > > I ported this series to tip:x86/boot (please post future versions against > > > that), > > > and beyond a trivial conflict with e820entry => e820_entry, it fails to > > > build on > > > 32-bit allmodconfig: > > > > > > ld: -r and -shared may not be used together > > > scripts/Makefile.build:294: recipe for target > > > 'arch/x86/boot/compressed/kaslr.o' failed > > > > > > ... which could be due to bad relocations, but I've not dug any further. > > > > Thanks, Ingo! > > > > I will find a x86_32 system to try allmodconfig. > > No need, on a 64-bit system just do: > > make ARCH=i386 allmodconfig > > and build the kernel the regular way.
Sorry for late update. I tried on a x86 64 system with "make ARCH=i386 allmodconfig", and saw the ld warning. I added a '-r' after -pie, the building passed. Seems including lib/ctype.c or lib/cmdline.c caused this. Will dig further to see what's going on. ifeq ($(CONFIG_X86_32),y) LDFLAGS += $(call ld-option, -pie -r) $(call ld-option, --no-dynamic-linker) else Thanks Baoquan
