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ARM64: Treat alignment faults as bus errors

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Summary:
ARM64 currently treats all data abort exceptions as page faults.  This
can cause infinite loops on non-page fault faults, such as alignment faults.

Since kernel-side alignment faults should be avoided, this adds support directly
to the el0 fault handler, instead of the data_abort() handler.

Test Plan: Tested on rpi3, with a misaligned ldm test.

Reviewed by:	andrew
Differential Revision:	https://reviews.freebsd.org/D22133
This commit is contained in:
Justin Hibbits 2019-10-30 15:30:40 +00:00
parent 1bce6aaf96
commit c7bb190966
1 changed files with 13 additions and 0 deletions
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13
sys/arm64/arm64/trap.c
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@ -87,6 +87,7 @@ int (*dtrace_invop_jump_addr)(struct trapframe *);
typedef void (abort_handler)(struct thread *, struct trapframe *, uint64_t,
uint64_t, int);
static abort_handler align_abort;
static abort_handler data_abort;
static abort_handler *abort_handlers[] = {
@ -100,6 +101,7 @@ static abort_handler *abort_handlers[] = {
[ISS_DATA_DFSC_PF_L1] = data_abort,
[ISS_DATA_DFSC_PF_L2] = data_abort,
[ISS_DATA_DFSC_PF_L3] = data_abort,
[ISS_DATA_DFSC_ALIGN] = align_abort,
};
static __inline void
@ -165,6 +167,17 @@ svc_handler(struct thread *td, struct trapframe *frame)
}
}
static void
align_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
uint64_t far, int lower)
{
if (!lower)
panic("Misaligned access from kernel space!");
call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr);
userret(td, frame);
}
static void
data_abort(struct thread *td, struct trapframe *frame, uint64_t esr,
uint64_t far, int lower)