From 5e5881143297c97207486349ec1cf9fd833b1510 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Fri, 28 Jul 2017 18:48:48 -0400 Subject: ARM: start_thread(): don't always clear all regs The elf_fdpic binary format driver has to initialize extra registers beside the stack and program counter as required by the corresponding ABI. So reinstate them after the regs structure has been cleared. While at it let's get rid of start_thread_nommu(). Signed-off-by: Nicolas Pitre Acked-by: Mickael GUENE Tested-by: Vincent Abriou Tested-by: Andras Szemzo --- arch/arm/include/asm/processor.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) (limited to 'arch/arm/include/asm/processor.h') diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index c3d5fc124a05..338cbe0a18ef 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -47,15 +47,24 @@ struct thread_struct { #define INIT_THREAD { } -#ifdef CONFIG_MMU -#define nommu_start_thread(regs) do { } while (0) -#else -#define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data -#endif - #define start_thread(regs,pc,sp) \ ({ \ + unsigned long r7, r8, r9; \ + \ + if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC)) { \ + r7 = regs->ARM_r7; \ + r8 = regs->ARM_r8; \ + r9 = regs->ARM_r9; \ + } \ memset(regs->uregs, 0, sizeof(regs->uregs)); \ + if (IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) && \ + current->personality & FDPIC_FUNCPTRS) { \ + regs->ARM_r7 = r7; \ + regs->ARM_r8 = r8; \ + regs->ARM_r9 = r9; \ + regs->ARM_r10 = current->mm->start_data; \ + } else if (!IS_ENABLED(CONFIG_MMU)) \ + regs->ARM_r10 = current->mm->start_data; \ if (current->personality & ADDR_LIMIT_32BIT) \ regs->ARM_cpsr = USR_MODE; \ else \ @@ -65,7 +74,6 @@ struct thread_struct { regs->ARM_cpsr |= PSR_ENDSTATE; \ regs->ARM_pc = pc & ~1; /* pc */ \ regs->ARM_sp = sp; /* sp */ \ - nommu_start_thread(regs); \ }) /* Forward declaration, a strange C thing */ -- cgit v1.2.1