The branch main has been updated by kd:
URL:
https://cgit.FreeBSD.org/src/commit/?id=4d2427f2c4451babe1bad600ae02c8a7c66031fe
commit 4d2427f2c4451babe1bad600ae02c8a7c66031fe
Author: Kornel Dulęba <k...@freebsd.org>
AuthorDate: 2023-02-20 14:44:36 +0000
Commit: Kornel Dulęba <k...@freebsd.org>
CommitDate: 2023-02-23 16:50:26 +0000
arm: Unbreak debugging programs that use FP instructions
Contrary to arm64, on armv7 get_vfpcontext/set_vfpcontext can be called
from cpu_ptrace. This can be triggered when gdb hits a breakpoint
in a userspace program.
Relax td == currthread assertion to account for that situation.
While here update an outdated comment in vfp_discard.
Reported by: Mark Millard <mark...@yahoo.com>
Tested by: Mark Millard <mark...@yahoo.com>
Differential Revision: https://reviews.freebsd.org/D38696
---
sys/arm/arm/exec_machdep.c | 17 ++++++-----------
sys/arm/arm/vfp.c | 2 --
2 files changed, 6 insertions(+), 13 deletions(-)
diff --git a/sys/arm/arm/exec_machdep.c b/sys/arm/arm/exec_machdep.c
index c14bd51146ef..96b382c9083f 100644
--- a/sys/arm/arm/exec_machdep.c
+++ b/sys/arm/arm/exec_machdep.c
@@ -100,19 +100,18 @@ get_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
{
struct pcb *pcb;
- MPASS(td == curthread);
+ MPASS(td == curthread || TD_IS_SUSPENDED(td) ||
+ P_SHOULDSTOP(td->td_proc));
pcb = td->td_pcb;
- if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
+ if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0 && td == curthread) {
critical_enter();
vfp_store(&pcb->pcb_vfpstate, false);
critical_exit();
}
KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
("Called get_vfpcontext while the kernel is using the VFP"));
- memcpy(vfp->mcv_reg, pcb->pcb_vfpstate.reg,
- sizeof(vfp->mcv_reg));
- vfp->mcv_fpscr = pcb->pcb_vfpstate.fpscr;
+ memcpy(vfp, &pcb->pcb_vfpstate, sizeof(*vfp));
}
/*
@@ -123,19 +122,15 @@ set_vfpcontext(struct thread *td, mcontext_vfp_t *vfp)
{
struct pcb *pcb;
- MPASS(td == curthread);
-
pcb = td->td_pcb;
- if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) {
+ if (td == curthread) {
critical_enter();
vfp_discard(td);
critical_exit();
}
KASSERT(pcb->pcb_vfpsaved == &pcb->pcb_vfpstate,
("Called set_vfpcontext while the kernel is using the VFP"));
- memcpy(pcb->pcb_vfpstate.reg, vfp->mcv_reg,
- sizeof(pcb->pcb_vfpstate.reg));
- pcb->pcb_vfpstate.fpscr = vfp->mcv_fpscr;
+ memcpy(&pcb->pcb_vfpstate, vfp, sizeof(*vfp));
}
#endif
diff --git a/sys/arm/arm/vfp.c b/sys/arm/arm/vfp.c
index 915d65c1b790..d51c4b6e0618 100644
--- a/sys/arm/arm/vfp.c
+++ b/sys/arm/arm/vfp.c
@@ -334,8 +334,6 @@ vfp_store(struct vfp_state *vfpsave, boolean_t disable_vfp)
* The current thread is dying. If the state currently in the hardware belongs
* to the current thread, set fpcurthread to NULL to indicate that the VFP
* hardware state does not belong to any thread. If the VFP is on, turn it
off.
- * Called only from cpu_throw(), so we don't have to worry about a context
- * switch here.
*/
void
vfp_discard(struct thread *td)
