From af09ab5e3fa7b6e137b135325a2ca00d57b4aea2 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Thu, 31 Mar 2016 10:05:37 +0100 Subject: [PATCH] MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y If CONFIG_RELOCATABLE is enabled, call relocate_kernel. This function will return the entry point of the relocated kernel if copy/relocate is sucessful or the original entry point if not. The stack pointer must then be pointed into the new image. Signed-off-by: Matt Redfearn Cc: Jonas Gorski Cc: linux-mips@linux-mips.org Cc: kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12984/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/head.S | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S index 4e4cc5b9a771..7dc043349d66 100644 --- a/arch/mips/kernel/head.S +++ b/arch/mips/kernel/head.S @@ -132,7 +132,27 @@ not_found: set_saved_sp sp, t0, t1 PTR_SUBU sp, 4 * SZREG # init stack pointer +#ifdef CONFIG_RELOCATABLE + /* Copy kernel and apply the relocations */ + jal relocate_kernel + + /* Repoint the sp into the new kernel image */ + PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE + PTR_ADDU sp, $28 + set_saved_sp sp, t0, t1 + PTR_SUBU sp, 4 * SZREG # init stack pointer + + /* + * relocate_kernel returns the entry point either + * in the relocated kernel or the original if for + * some reason relocation failed - jump there now + * with instruction hazard barrier because of the + * newly sync'd icache. + */ + jr.hb v0 +#else j start_kernel +#endif END(kernel_entry) #ifdef CONFIG_SMP -- 2.20.1