From: Yinghai Lu <yinghai@xxxxxxxxxx> memmap=exactmap will throw away all original, but also until then user defined (through other provided memmap= parameters) areas. That means all memmap= boot parameters passed before a memmap=exactmap parameter are not recognized. Without this fix: memmap=x at y memmap=exactmap memmap=i#k only i#k would get recognized. This is wrong, this fix will only throw away all original e820 areas once when memmap=exactmap is found in the whole boot command line and before any other memmap= option is parsed. Reviewed-by: Thomas Renninger <trenn at suse.de> Signed-off-by: Thomas Renninger <trenn at suse.de> --- arch/x86/kernel/e820.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index d32abea..dc0b9f0 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -835,6 +835,8 @@ static int __init parse_memopt(char *p) } early_param("mem", parse_memopt); +static bool __initdata exactmap_parsed; + static int __init parse_memmap_one(char *p) { char *oldp; @@ -844,6 +846,10 @@ static int __init parse_memmap_one(char *p) return -EINVAL; if (!strncmp(p, "exactmap", 8)) { + if (exactmap_parsed) + return 0; + + exactmap_parsed = true; #ifdef CONFIG_CRASH_DUMP /* * If we are doing a crash dump, we still need to know @@ -879,6 +885,12 @@ static int __init parse_memmap_one(char *p) } static int __init parse_memmap_opt(char *str) { + char *p = boot_command_line; + + p = strstr(p, "exactmap"); + if (p) + parse_memmap_one("exactmap"); + while (str) { char *k = strchr(str, ','); -- 1.7.6.1