diff options
| -rw-r--r-- | kexec/arch/i386/kexec-x86-common.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/kexec/arch/i386/kexec-x86-common.c b/kexec/arch/i386/kexec-x86-common.c index ba54973..474e680 100644 --- a/kexec/arch/i386/kexec-x86-common.c +++ b/kexec/arch/i386/kexec-x86-common.c @@ -202,6 +202,28 @@ again: } /** + * Detect the add_efi_memmap kernel parameter. + * + * On some EFI-based systems, the e820 map is empty, or does not contain a + * complete memory map. The add_efi_memmap parameter adds these entries to + * the kernel's memory map, but does not add them under sysfs, which causes + * kexec to fail in a way similar to how it does not work on Xen. + * + * @return 1 if parameter is present, 0 if not or if an error occurs. + */ +int efi_map_added( void ) { + char buf[512], *res; + FILE *fp = fopen( "/proc/cmdline", "r" ); + if( fp ) { + res = fgets( buf, 512, fp ); + fclose( fp ); + return strstr( buf, "add_efi_memmap" ) != NULL; + } else { + return 0; + } +} + +/** * Return a sorted list of memory ranges. * * If we have the /sys/firmware/memmap interface, then use that. If not, @@ -227,7 +249,7 @@ int get_memory_ranges(struct memory_range **range, int *ranges, * even if we have /sys/firmware/memmap. Without that, /proc/vmcore * is empty in the kdump kernel. */ - if (!xen_present() && have_sys_firmware_memmap()) { + if (!efi_map_added() && !xen_present() && have_sys_firmware_memmap()) { ret = get_memory_ranges_sysfs(range, ranges); if (!ret) ret = fixup_memory_ranges_sysfs(range, ranges); |