From b029ef7fe618c6fa0482958422cc362905c15376 Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Mon, 13 Sep 2021 15:24:34 +0000 Subject: Restrict spsr updated in the arm64 set_regs* When using ptrace(2) on arm64 to set registers in a 32-bit program we need to take care to only set some of the fields. Follow the existing arm64 path and only let the user set the flags fields. This is also the case in the arm kernel so fixes a change in behaviour between the two. While here update set_regs to only set spsr and elr once. Sponsored by: The FreeBSD Foundation --- sys/arm64/arm64/machdep.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/sys/arm64/arm64/machdep.c b/sys/arm64/arm64/machdep.c index ee6f5157f5f3..89c4f21134f8 100644 --- a/sys/arm64/arm64/machdep.c +++ b/sys/arm64/arm64/machdep.c @@ -254,9 +254,7 @@ set_regs(struct thread *td, struct reg *regs) frame = td->td_frame; frame->tf_sp = regs->sp; frame->tf_lr = regs->lr; - frame->tf_elr = regs->elr; frame->tf_spsr &= ~PSR_FLAGS; - frame->tf_spsr |= regs->spsr & PSR_FLAGS; memcpy(frame->tf_x, regs->x, sizeof(frame->tf_x)); @@ -268,9 +266,13 @@ set_regs(struct thread *td, struct reg *regs) * it put it. */ frame->tf_elr = regs->x[15]; - frame->tf_spsr = regs->x[16] & PSR_FLAGS; - } + frame->tf_spsr |= regs->x[16] & PSR_FLAGS; + } else #endif + { + frame->tf_elr = regs->elr; + frame->tf_spsr |= regs->spsr & PSR_FLAGS; + } return (0); } @@ -490,7 +492,8 @@ set_regs32(struct thread *td, struct reg32 *regs) tf->tf_x[13] = regs->r_sp; tf->tf_x[14] = regs->r_lr; tf->tf_elr = regs->r_pc; - tf->tf_spsr = regs->r_cpsr; + tf->tf_spsr &= ~PSR_FLAGS; + tf->tf_spsr |= regs->r_cpsr & PSR_FLAGS; return (0); } -- cgit v1.2.3