On 03/14/14 at 02:47pm, Dave Young wrote: > On 03/14/14 at 02:12pm, Dave Young wrote: > > On 03/12/14 at 11:13am, WANG Chao wrote: > > > Currently kexec hard code X86_64_KERNEL_TEXT_SIZE to 512M. With kASLR > > > enabled (CONFIG_RANDOMIZED_BASE=y), kernel image base offset could be > > > randomized from 0 to 1GB and kexec-tools fails to get kernel virtual > > > address from /proc/kcore when the offset is >512M. > > > > > > Now extend X86_64_KERNEL_TEXT_SIZE to 1GB to adapt kASLR. > > > > > > Signed-off-by: WANG Chao <chaowang at redhat.com> > > > --- > > > kexec/arch/i386/crashdump-x86.h | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h > > > index e68b626..a5b2dfd 100644 > > > --- a/kexec/arch/i386/crashdump-x86.h > > > +++ b/kexec/arch/i386/crashdump-x86.h > > > @@ -18,7 +18,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline, > > > #define X86_64_MAXMEM 0x3fffffffffffUL > > > > > > /* Kernel text size */ > > > -#define X86_64_KERNEL_TEXT_SIZE (512UL*1024*1024) > > > +#define X86_64_KERNEL_TEXT_SIZE (1UL*1024*1024*1024) > > > > Should define a new macro such as: X86_KERNEL_TEXT_START_LIMIT (1UL*1024*1024*1024) > > and then check end addr with X86_64_KERNEL_TEXT_SIZE + X86_64_KERNEL_TEXT_SIZE > > I means check ktext with range <1G - 1.5G> You're right. I think it's fine adding new macro X86_64_RANDOMIZE_BASE_MAX_OFFSET as 0x40000000 (1G) and doing the following check: (start >= X86_64__START_KERNEL_map) && (start <= X86_64__START_KERNEL_map + X86_64_RANDOMIZE_MAX_BASE_OFFSET) && (end - start <= X86_64_KERNEL_TEXT_SIZE) What do you think? > > > > > Previously I did not find this problem probably because kernel text happen to randomized > > to a address < 512M.. > > > > BTW since we can get physical start and size from /proc/iomem, why not just get > > vaddr by phys_start + PAGE_OFFSET. > > Ignore above question, /proc/iomem can not get right end addr which includes not only code > and data. > > Current kaslr has a limit up value 0x40000000 in Kconfig so the biggest value is 1G, but > it could be change to other value in the future. It will be ideal that we can export the > end addr somewhere for example /proc/iomem. We have to use kcore to determine start/end until something happens in /proc/iomem or elsewhere. Thanks WANG Chao > > > > > > > > > #define CRASH_MAX_MEMMAP_NR CRASH_MAX_MEMORY_RANGES > > > #define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2) > > > -- > > > 1.8.5.3 > > > > > > > > > _______________________________________________ > > > kexec mailing list > > > kexec at lists.infradead.org > > > http://lists.infradead.org/mailman/listinfo/kexec
