On Mon, Apr 08, 2019 at 01:58:35PM +0800, Pingfan Liu wrote: > crashkernel=x@y or or =range1:size1[,range2:size2,...]@offset option may > fail to reserve the required memory region if KASLR puts kernel into the > region. To avoid this uncertainty, asking KASLR to skip the required > region. > > Signed-off-by: Pingfan Liu <kernelf...@gmail.com> > Cc: Thomas Gleixner <t...@linutronix.de> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Borislav Petkov <b...@alien8.de> > Cc: "H. Peter Anvin" <h...@zytor.com> > Cc: Baoquan He <b...@redhat.com> > Cc: Will Deacon <will.dea...@arm.com> > Cc: Nicolas Pitre <n...@linaro.org> > Cc: Vivek Goyal <vgo...@redhat.com> > Cc: Chao Fan <fanc.f...@cn.fujitsu.com> > Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> > Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> > CC: Hari Bathini <hbath...@linux.vnet.ibm.com> > Cc: linux-kernel@vger.kernel.org > --- > arch/x86/boot/compressed/kaslr.c | 40 > ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > diff --git a/arch/x86/boot/compressed/kaslr.c > b/arch/x86/boot/compressed/kaslr.c > index 2e53c05..765a593 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -107,6 +107,7 @@ enum mem_avoid_index { > MEM_AVOID_BOOTPARAMS, > MEM_AVOID_MEMMAP_BEGIN, > MEM_AVOID_MEMMAP_END = MEM_AVOID_MEMMAP_BEGIN + MAX_MEMMAP_REGIONS - 1, > + MEM_AVOID_CRASHKERNEL, > MEM_AVOID_MAX, > }; > > @@ -131,6 +132,11 @@ char *skip_spaces(const char *str) > } > #include "../../../../lib/ctype.c" > #include "../../../../lib/cmdline.c" > +#ifdef CONFIG_CRASH_CORE > +#define printk > +#define _BOOT_KASLR > +#include "../../../../lib/parse_crashkernel.c" > +#endif > > static int > parse_memmap(char *p, unsigned long long *start, unsigned long long *size) > @@ -292,6 +298,39 @@ static void handle_mem_options(void) > return; > } > > +static u64 mem_ram_size(void) > +{ > + struct boot_e820_entry *entry; > + u64 total_sz = 0; > + int i; > + > + for (i = 0; i < boot_params->e820_entries; i++) { > + entry = &boot_params->e820_table[i]; > + /* Skip non-RAM entries. */ > + if (entry->type != E820_TYPE_RAM) > + continue; > + total_sz += entry->size; > + } > + return total_sz; > +} > + > +/* > + * For crashkernel=size@offset or =range1:size1[,range2:size2,...]@offset > + * options, recording mem_avoid for them. > + */ > +static void handle_crashkernel_options(void) > +{ > + unsigned long long crash_size, crash_base = 0; > + char *cmdline = (char *)get_cmd_line_ptr(); > + u64 total_sz = mem_ram_size(); > + > + parse_crashkernel(cmdline, total_sz, &crash_size, &crash_base);
That function has a return value which you could test. And then you don't need to set crash_base to 0 above. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.