Final patch: --- From: Yinghai Lu <ying...@kernel.org> Date: Sat, 7 Mar 2015 14:07:17 -0800 Subject: [PATCH] x86/setup: Don't overlap vmlinux's brk with compressed kernel's data
We already do move the compressed kernel close to the end of the buffer. However, there's still overlapping beween kernel proper's .brk/.bss and compressed kernel's data section. Extend init_size so that kernel proper's .bss and .brk sections do not overlap with compressed kernel's data section (see arch/x86/boot/compressed/misc.c). The increase is from _rodata to _end in the compressed kernel (arch/x86/boot/compressed/vmlinux) which is something around ~90K on a kernel with everything enabled in arch/x86/boot/ which gets linked into vmlinux. Signed-off-by: Yinghai Lu <ying...@kernel.org> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Matt Fleming <matt.flem...@intel.com> Cc: Kees Cook <keesc...@chromium.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Jiri Kosina <jkos...@suse.cz> Cc: linux-...@vger.kernel.org Cc: Ingo Molnar <mi...@redhat.com> Cc: Baoquan He <b...@redhat.com> Link: http://lkml.kernel.org/r/1425766041-6551-4-git-send-email-ying...@kernel.org Fixes: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation") [ Rewrite commit message; rename ADDON_ZO_SIZE to INIT_SIZE_PAD; improve comments; measure size increase ] Signed-off-by: --- arch/x86/boot/Makefile | 2 +- arch/x86/boot/compressed/vmlinux.lds.S | 1 + arch/x86/boot/header.S | 13 +++++++++++-- 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 57bbf2fb21f6..863ef25dcf60 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -86,7 +86,7 @@ targets += voffset.h $(obj)/voffset.h: vmlinux FORCE $(call if_changed,voffset) -sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|z_.*\)$$/\#define ZO_\2 0x\1/p' +sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [ABCDGRSTVW] \(startup_32\|startup_64\|efi32_stub_entry\|efi64_stub_entry\|efi_pe_entry\|input_data\|_end\|_rodata\|z_.*\)$$/\#define ZO_\2 0x\1/p' quiet_cmd_zoffset = ZOFFSET $@ cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@ diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index a80acabb80ec..45081235ce64 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -35,6 +35,7 @@ SECTIONS *(.text.*) _etext = . ; } + . = ALIGN(PAGE_SIZE); /* keep INIT_SIZE_PAD in header.S page-aligned */ .rodata : { _rodata = . ; *(.rodata) /* read-only data */ diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S index 9bfab22efdf7..db46aa45906d 100644 --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -440,13 +440,22 @@ setup_data: .quad 0 # 64-bit physical pointer to pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr + #define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset) + +/* + * Additional padding so that compressed kernel's .data section doesn't overlap + * with kernel proper's .bss/.brk sections. + */ +#define INIT_SIZE_PAD (ZO__end - ZO__rodata) #define VO_INIT_SIZE (VO__end - VO__text) + #if ZO_INIT_SIZE > VO_INIT_SIZE -#define INIT_SIZE ZO_INIT_SIZE +#define INIT_SIZE (ZO_INIT_SIZE + INIT_SIZE_PAD) #else -#define INIT_SIZE VO_INIT_SIZE +#define INIT_SIZE (VO_INIT_SIZE + INIT_SIZE_PAD) #endif + init_size: .long INIT_SIZE # kernel initialization size handover_offset: .long 0 # Filled in by build.c -- 2.2.0.33.gc18b867 -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
