From 22a57f5896df218356bae6203dfaf04bcfd6c88c Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 2 Aug 2010 15:34:44 -0700 Subject: x86, setup: Allow global variables and functions in the decompressor In order for global variables and functions to work in the decompressor, we need to fix up the GOT in assembly code. Signed-off-by: H. Peter Anvin LKML-Reference: <4C57382E.8050501@zytor.com> --- arch/x86/boot/compressed/head_32.S | 13 +++++++++++++ arch/x86/boot/compressed/head_64.S | 13 +++++++++++++ arch/x86/boot/compressed/vmlinux.lds.S | 6 ++++++ 3 files changed, 32 insertions(+) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index f543b70ffae2..67a655a39ce4 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -123,6 +123,19 @@ relocated: shrl $2, %ecx rep stosl +/* + * Adjust our own GOT + */ + leal _got(%ebx), %edx + leal _egot(%ebx), %ecx +1: + cmpl %ecx, %edx + jae 2f + addl %ebx, (%edx) + addl $4, %edx + jmp 1b +2: + /* * Do the decompression, and jump to the new kernel.. */ diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index faff0dc9c06a..52f85a196fa0 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -279,6 +279,19 @@ relocated: shrq $3, %rcx rep stosq +/* + * Adjust our own GOT + */ + leaq _got(%rip), %rdx + leaq _egot(%rip), %rcx +1: + cmpq %rcx, %rdx + jae 2f + addq %rbx, (%rdx) + addq $8, %rdx + jmp 1b +2: + /* * Do the decompression, and jump to the new kernel.. */ diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 5ddabceee124..34d047c98284 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -41,6 +41,12 @@ SECTIONS *(.rodata.*) _erodata = . ; } + .got : { + _got = .; + KEEP(*(.got.plt)) + KEEP(*(.got)) + _egot = .; + } .data : { _data = . ; *(.data) -- cgit v1.2.3