From 0f72efaac7becb2c0b49537cfaae3d7efd74d568 Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Thu, 27 Dec 2018 14:14:41 +0000 Subject: [PATCH] Pass VM_PROT_EXECUTE to vm_fault for instruction faults. We need to tell vm_fault the reason for the fault was because we tried to execute from the memory location. Without this it may return with success as we only request read-only memory, then we return to the same location and try to execute from the same memory address. This leads to an infinite loop raising the same fault and returning to the same invalid location. MFC after: 1 week Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D18511 --- sys/arm64/arm64/trap.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/sys/arm64/arm64/trap.c b/sys/arm64/arm64/trap.c index 8de175fb387..5740af92170 100644 --- a/sys/arm64/arm64/trap.c +++ b/sys/arm64/arm64/trap.c @@ -149,7 +149,7 @@ svc_handler(struct thread *td, struct trapframe *frame) static void data_abort(struct thread *td, struct trapframe *frame, uint64_t esr, - uint64_t far, int lower) + uint64_t far, int lower, int exec) { struct vm_map *map; struct proc *p; @@ -229,6 +229,8 @@ no_pmap_fault: va = trunc_page(far); ftype = ((esr >> 6) & 1) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; + if (exec) + ftype |= VM_PROT_EXECUTE; /* Fault in the page. */ error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); @@ -336,7 +338,8 @@ do_el1h_sync(struct thread *td, struct trapframe *frame) case EXCP_DATA_ABORT: far = READ_SPECIALREG(far_el1); intr_enable(); - data_abort(td, frame, esr, far, 0); + data_abort(td, frame, esr, far, 0, + exception == EXCP_INSN_ABORT); break; case EXCP_BRK: #ifdef KDTRACE_HOOKS @@ -433,7 +436,8 @@ do_el0_sync(struct thread *td, struct trapframe *frame) case EXCP_INSN_ABORT_L: case EXCP_DATA_ABORT_L: case EXCP_DATA_ABORT: - data_abort(td, frame, esr, far, 1); + data_abort(td, frame, esr, far, 1, + exception == EXCP_INSN_ABORT_L); break; case EXCP_UNKNOWN: if (!undef_insn(0, frame))