From: Mike Rapoport <[email protected]> Currently the first several pages are reserved both to avoid leaking their contents on systems with L1TF and to avoid corrupting BIOS memory.
Merge the two memory reservations. Signed-off-by: Mike Rapoport <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Acked-by: Borislav Petkov <[email protected]> --- arch/x86/kernel/setup.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 3b582406363a..b36624e3dc9e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -703,20 +703,6 @@ static int __init parse_reservelow(char *p) early_param("reservelow", parse_reservelow); -static void __init trim_low_memory_range(void) -{ - /* - * A special case is the first 4Kb of memory; - * This is a BIOS owned area, not kernel ram, but generally - * not listed as such in the E820 table. - * - * This typically reserves additional memory (64KiB by default) - * since some BIOSes are known to corrupt low memory. See the - * Kconfig help text for X86_RESERVE_LOW. - */ - memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE)); -} - static void __init early_reserve_memory(void) { /* @@ -729,10 +715,17 @@ static void __init early_reserve_memory(void) (unsigned long)__end_of_kernel_reserve - (unsigned long)_text); /* - * Make sure page 0 is always reserved because on systems with - * L1TF its contents can be leaked to user processes. + * The first 4Kb of memory is a BIOS owned area, but generally it is + * not listed as such in the E820 table. + * + * Reserve the first memory page and typically some additional + * memory (64KiB by default) since some BIOSes are known to corrupt + * low memory. See the Kconfig help text for X86_RESERVE_LOW. + * + * In addition, make sure page 0 is always reserved because on + * systems with L1TF its contents can be leaked to user processes. */ - memblock_reserve(0, PAGE_SIZE); + memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE)); early_reserve_initrd(); @@ -745,7 +738,6 @@ static void __init early_reserve_memory(void) reserve_bios_regions(); trim_snb_memory(); - trim_low_memory_range(); } /* -- 2.28.0
