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 ++++++++++++++++++++++++++++++++++++++++ lib/parse_crashkernel.c | 10 ++++++++++ 2 files changed, 50 insertions(+) diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c index 2e53c05..12f72a3 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; + char *cmdline = (char *)get_cmd_line_ptr(); + u64 total_sz = mem_ram_size(); + + parse_crashkernel(cmdline, total_sz, &crash_size, &crash_base); + if (crash_base) { + mem_avoid[MEM_AVOID_CRASHKERNEL].start = crash_base; + mem_avoid[MEM_AVOID_CRASHKERNEL].size = crash_size; + } +} + /* * In theory, KASLR can put the kernel anywhere in the range of [16M, 64T). * The mem_avoid array is used to store the ranges that need to be avoided @@ -414,6 +453,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size, /* Mark the memmap regions we need to avoid */ handle_mem_options(); + handle_crashkernel_options(); /* Enumerate the immovable memory regions */ num_immovable_mem = count_immovable_mem_regions(); diff --git a/lib/parse_crashkernel.c b/lib/parse_crashkernel.c index b9a8dc6..4644379 100644 --- a/lib/parse_crashkernel.c +++ b/lib/parse_crashkernel.c @@ -137,6 +137,7 @@ static __initdata char *suffix_tbl[] = { [SUFFIX_NULL] = NULL, }; +#ifndef _BOOT_KASLR /* * That function parses "suffix" crashkernel command lines like * @@ -169,6 +170,7 @@ static int __init parse_crashkernel_suffix(char *cmdline, return 0; } +#endif static __init char *get_last_crashkernel(char *cmdline, const char *name, @@ -232,9 +234,11 @@ static int __init __parse_crashkernel(char *cmdline, ck_cmdline += strlen(name); +#ifndef _BOOT_KASLR if (suffix) return parse_crashkernel_suffix(ck_cmdline, crash_size, suffix); +#endif /* * if the commandline contains a ':', then that's the extended * syntax -- if not, it must be the classic syntax @@ -261,6 +265,11 @@ int __init parse_crashkernel(char *cmdline, "crashkernel=", NULL); } +/* + * At boot stage, KASLR does not care about crashkernel=size,[high|low], which + * never specifies the offset of region. + */ +#ifndef _BOOT_KASLR int __init parse_crashkernel_high(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, @@ -278,3 +287,4 @@ int __init parse_crashkernel_low(char *cmdline, return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, "crashkernel=", suffix_tbl[SUFFIX_LOW]); } +#endif -- 2.7.4