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Add some more checking to the RISC-V page fault handler.

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- Panic immediately if witness says we're holding non-sleepable locks.
  This helps ensure that we don't recurse on the pmap lock in
  pmap_fault_fixup().
- Panic if the kernel faults on a user address without setting an
  onfault handler.
- Panic if the fault occurred in a critical section or interrupt
  handler, like we do on other platforms.
- Fix some style issues in trap_pfault().

Reviewed by:	jhb
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18561
This commit is contained in:
Mark Johnston 2018-12-14 21:07:12 +00:00
parent 105c317166
commit 3ec68206f5
1 changed files with 22 additions and 18 deletions
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40
sys/riscv/riscv/trap.c
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@ -167,7 +167,7 @@ svc_handler(struct trapframe *frame)
}
static void
data_abort(struct trapframe *frame, int lower)
data_abort(struct trapframe *frame, int usermode)
{
struct vm_map *map;
uint64_t sbadaddr;
@ -176,9 +176,7 @@ data_abort(struct trapframe *frame, int lower)
vm_prot_t ftype;
vm_offset_t va;
struct proc *p;
int ucode;
int error;
int sig;
int error, sig, ucode;
#ifdef KDB
if (kdb_active) {
@ -188,19 +186,23 @@ data_abort(struct trapframe *frame, int lower)
#endif
td = curthread;
p = td->td_proc;
pcb = td->td_pcb;
sbadaddr = frame->tf_sbadaddr;
p = td->td_proc;
if (td->td_critnest != 0 || td->td_intr_nesting_level != 0 ||
WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
"Kernel page fault") != 0)
goto fatal;
if (lower)
if (usermode)
map = &td->td_proc->p_vmspace->vm_map;
else if (sbadaddr >= VM_MAX_USER_ADDRESS)
map = kernel_map;
else {
/* The top bit tells us which range to use */
if ((sbadaddr >> 63) == 1)
map = kernel_map;
else
map = &td->td_proc->p_vmspace->vm_map;
if (pcb->pcb_onfault == 0)
goto fatal;
map = &td->td_proc->p_vmspace->vm_map;
}
va = trunc_page(sbadaddr);
@ -241,7 +243,7 @@ data_abort(struct trapframe *frame, int lower)
}
if (error != KERN_SUCCESS) {
if (lower) {
if (usermode) {
sig = SIGSEGV;
if (error == KERN_PROTECTION_FAILURE)
ucode = SEGV_ACCERR;
@ -249,21 +251,23 @@ data_abort(struct trapframe *frame, int lower)
ucode = SEGV_MAPERR;
call_trapsignal(td, sig, ucode, (void *)sbadaddr);
} else {
if (td->td_intr_nesting_level == 0 &&
pcb->pcb_onfault != 0) {
if (pcb->pcb_onfault != 0) {
frame->tf_a[0] = error;
frame->tf_sepc = pcb->pcb_onfault;
return;
}
dump_regs(frame);
panic("vm_fault failed: %lx, va 0x%016lx",
frame->tf_sepc, sbadaddr);
goto fatal;
}
}
done:
if (lower)
if (usermode)
userret(td, frame);
return;
fatal:
dump_regs(frame);
panic("Fatal page fault at %#lx: %#016lx", frame->tf_sepc, sbadaddr);
}
void