> On May 7, 2020, at 2:30 PM, Nick Desaulniers <[email protected]> wrote:
>
> On Thu, May 7, 2020 at 6:42 AM Qian Cai <[email protected]> wrote:
>>
>> Running a Clang (9.0.1) build kernel with UBSAN generated a few warnings
>> during boot,
>
> Very cool, these reports are so nice! They hand you everything on a
> silver platter. Thanks for testing/sending! Let's take a look.
>
>>
>> [ 0.000000] UBSAN: null-ptr-deref in drivers/acpi/acpica/tbfadt.c:459:37
>> [ 0.000000] member access within null pointer of type 'struct
>> acpi_table_fadt'
>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted
>> 5.7.0-rc4-next-20200507 #2
>> [ 0.000000] Call trace:
>> [ 0.000000] dump_backtrace+0x0/0x22c
>> [ 0.000000] show_stack+0x28/0x34
>> [ 0.000000] dump_stack+0x104/0x194
>> [ 0.000000] handle_null_ptr_deref+0xdc/0x10c
>> [ 0.000000] __ubsan_handle_type_mismatch_v1+0x64/0x78
>> [ 0.000000] acpi_tb_create_local_fadt+0x104/0x6ec
>
> ok so acpi_tb_create_local_fadt() dereferenced a `null pointer of type
> 'struct acpi_table_fadt'` in null-ptr-deref in
> drivers/acpi/acpica/tbfadt.c:459.
>
> That line number doesn't line up with linux-next; which tree was this?
> That will probably help track these down faster.
It is linux-next indeed as in the signature.
next-20200507
# ./scripts/faddr2line vmlinux acpi_tb_create_local_fadt+0x104/0x6ec
acpi_tb_create_local_fadt+0x104/0x6ec:
acpi_tb_convert_fadt at drivers/acpi/acpica/tbfadt.c:459
(inlined by) acpi_tb_create_local_fadt at drivers/acpi/acpica/tbfadt.c:388
This line,
if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {
acpi_gbl_FADT was defined in,
.//include/acpi/acpixf.h:266:ACPI_GLOBAL(struct acpi_table_fadt, acpi_gbl_FADT);
#ifdef DEFINE_ACPI_GLOBALS
#define ACPI_GLOBAL(type,name) \
extern type name; \
type name
#define ACPI_INIT_GLOBAL(type,name,value) \
type name=value
#else
#ifndef ACPI_GLOBAL
#define ACPI_GLOBAL(type,name) \
extern type name
#endif
#ifndef ACPI_INIT_GLOBAL
#define ACPI_INIT_GLOBAL(type,name,value) \
extern type name
#endif
#endif
I looks like DEFINE_ACPI_GLOBALS should be set in
drivers/acpi/acpica/utglobal.c.
