From 9d6c0b6fbb95bbf793c44625fd39b3a583028ada Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Wed, 7 Aug 2019 15:27:33 -0700 Subject: [PATCH] Revert "Revert "Revert "Revert "x86/mm: Identify the end of the kernel area to be reserved"""" This reverts commit e78f95acac98aa2bc8b655a8873f7b8755f72b70. This adds back the original commit c603a309cc75 ("x86/mm: Identify the end of the kernel area to be reserved") Bug: 138463564 Signed-off-by: Nick Desaulniers Change-Id: Ia01a9b914beebf392a670f8b8238ebceeb361a1d --- arch/x86/include/asm/sections.h | 2 ++ arch/x86/kernel/setup.c | 8 +++++++- arch/x86/kernel/vmlinux.lds.S | 9 ++++++++- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h index 8ea1cfdbeabc..71b32f2570ab 100644 --- a/arch/x86/include/asm/sections.h +++ b/arch/x86/include/asm/sections.h @@ -13,4 +13,6 @@ extern char __end_rodata_aligned[]; extern char __end_rodata_hpage_align[]; #endif +extern char __end_of_kernel_reserve[]; + #endif /* _ASM_X86_SECTIONS_H */ diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index f007d910a6e6..77ea96b794bd 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -836,8 +836,14 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) void __init setup_arch(char **cmdline_p) { + /* + * Reserve the memory occupied by the kernel between _text and + * __end_of_kernel_reserve symbols. Any kernel sections after the + * __end_of_kernel_reserve symbol must be explicitly reserved with a + * separate memblock_reserve() or they will be discarded. + */ memblock_reserve(__pa_symbol(_text), - (unsigned long)__bss_stop - (unsigned long)_text); + (unsigned long)__end_of_kernel_reserve - (unsigned long)_text); /* * Make sure page 0 is always reserved because on systems with diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 4f062d33ef73..e2feacf921a0 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -368,6 +368,14 @@ SECTIONS __bss_stop = .; } + /* + * The memory occupied from _text to here, __end_of_kernel_reserve, is + * automatically reserved in setup_arch(). Anything after here must be + * explicitly reserved using memblock_reserve() or it will be discarded + * and treated as available memory. + */ + __end_of_kernel_reserve = .; + . = ALIGN(PAGE_SIZE); .brk : AT(ADDR(.brk) - LOAD_OFFSET) { __brk_base = .; @@ -407,7 +415,6 @@ SECTIONS STABS_DEBUG DWARF_DEBUG - /* Sections to be discarded */ DISCARDS /DISCARD/ : { *(.eh_frame)