On Tue, Apr 19, 2022 at 11:19 PM Tony Luck <tony.luck@xxxxxxxxx> wrote: > > Some validation tests dynamically inject errors into memory used by > applications to check that the system can recover from a variety of > poison consumption sceenarios. > > But sometimes the virtual address picked by these tests is mapped to > the zero page. > > This causes additional unexpected machine checks as other processes that > map the zero page also consume the poison. > > Disallow injection to the zero page. > > Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> > > --- > I picked -EADDRINUSE as a somewhat descriptive error code distinct > fromm -EINVAL used elsewhere in EINJ, but I'm not strongly attached > to it. Any other non -EINVAL value would be as good an indicator to > the validation tests that they shouldn't inject to this address. > --- > drivers/acpi/apei/einj.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c > index 95cc2a9f3e05..d4326ec12d29 100644 > --- a/drivers/acpi/apei/einj.c > +++ b/drivers/acpi/apei/einj.c > @@ -549,6 +549,9 @@ static int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2, > !arch_is_platform_page(base_addr))) > return -EINVAL; > > + if (is_zero_pfn(base_addr >> PAGE_SHIFT)) > + return -EADDRINUSE; > + > inject: > mutex_lock(&einj_mutex); > rc = __einj_error_inject(type, flags, param1, param2, param3, param4); > -- Applied as 5.19 material, thanks!
