github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-03 03:53:37 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: arm64: Avoid BUG-ing from the host abort path

Browse Source 
Under certain circumstances __get_fault_info() may resolve the faulting
address using the AT instruction. Given that this is being done outside
of the host lock critical section, it is racy and the resolution via AT
may fail. We currently BUG() in this situation, which is obviously less
than ideal. Moving the address resolution to the critical section may
have a performance impact, so let's keep it where it is, but bail out
and return to the host to try a second time.

Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-7-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Quentin Perret 2024-04-23 16:05:14 +01:00 committed by Marc Zyngier
parent cb16301626
commit 02949f36bc
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/arm64/kvm/hyp/nvhe/mem_protect.c
View File

@ -533,7 +533,13 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
int ret = 0;
esr = read_sysreg_el2(SYS_ESR);
BUG_ON(!__get_fault_info(esr, &fault));
if (!__get_fault_info(esr, &fault)) {
/*
* We've presumably raced with a page-table change which caused
* AT to fail, try again.
*/
return;
}
addr = (fault.hpfar_el2 & HPFAR_MASK) << 8;
ret = host_stage2_idmap(addr);