From facd04a904ff6cdc6ee85d6e85d500f478a1bec4 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 27 Aug 2019 13:30:06 +1000 Subject: [PATCH] powerpc: convert to copy_thread_tls Commit 3033f14ab78c3 ("clone: support passing tls argument via C rather than pt_regs magic") introduced the HAVE_COPY_THREAD_TLS option. Use it to avoid a subtle assumption about the argument ordering of clone type syscalls. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190827033010.28090-2-npiggin@gmail.com --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/process.c | 9 +++++---- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3d65084..cfb2185 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -184,6 +184,7 @@ config PPC select HAVE_STACKPROTECTOR if PPC64 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13) select HAVE_STACKPROTECTOR if PPC32 && $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r2) select HAVE_CONTEXT_TRACKING if PPC64 + select HAVE_COPY_THREAD_TLS select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_STACKOVERFLOW select HAVE_DYNAMIC_FTRACE diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 8fc4de0..24621e7 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1600,8 +1600,9 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) /* * Copy architecture-specific thread state */ -int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long kthread_arg, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long usp, + unsigned long kthread_arg, struct task_struct *p, + unsigned long tls) { struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); @@ -1642,10 +1643,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, if (clone_flags & CLONE_SETTLS) { #ifdef CONFIG_PPC64 if (!is_32bit_task()) - childregs->gpr[13] = childregs->gpr[6]; + childregs->gpr[13] = tls; else #endif - childregs->gpr[2] = childregs->gpr[6]; + childregs->gpr[2] = tls; } f = ret_from_fork; -- 2.7.4