On 2022/06/01 1:41, Linus Torvalds wrote:
On Tue, May 31, 2022 at 1:04 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
As an experiment: what kind of results would we get when looking
for packed structures and unions that contain any of these:
I don't think we have that. Not only because it would already cause
breakage, but simply because the kinds of structures that people pack
aren't generally the kind that contain these kinds of things.
That said, you might have a struct that is packed, but that
intentionally aligns parts of itself, so it *could* be valid.
But it would probably not be a bad idea to check that packed
structures/unions don't have atomic types or locks in them. I _think_
we're all good, but who knows..
I am Julia's student at INRIA and I heard from her that there is an
opportunity to use Coccinelle to find specific types in packed struct or
enum.
I found 13 definitions of packed structure that contains:
> - spinlock_t
> - atomic_t
> - dma_addr_t
> - phys_addr_t
> - size_t
> - struct mutex
> - struct device
- raw_spinlock_t
== Results ==
security/tomoyo/common.h: atomic_t in tomoyo_shared_acl_head
drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls.h: spinlock_t in
key_map
include/linux/ti-emif-sram.h: phys_addr_t in ti_emif_pm_data
drivers/scsi/wd719x.h: dma_addr_t in wd719x_scb
drivers/net/wireless/intel/ipw2x00/ipw2200.h: dma_addr_t in clx2_queue
drivers/infiniband/hw/irdma/osdep.h: dma_addr_t in irdma_dma_mem
drivers/infiniband/core/mad_priv.h: size_t in ib_mad_private
drivers/crypto/qat/qat_common/qat_asym_algs.c:
- dma_addr_t in qat_rsa_ctx
- dma_addr_t in qat_dh_ctx
drivers/atm/idt77252.h: dma_addr_t in idt77252_skb_prv
arch/s390/include/asm/kvm_host.h: atomic_t in kvm_s390_sie_block
drivers/net/wireless/ath/ath10k/core.h: dma_addr_t in ath10k_skb_cb
drivers/net/wireless/ath/ath11k/core.h: dma_addr_t in ath10k_skb_cb
drivers/crypto/ccp/ccp-dev.h: dma_addr_t in ccp_dma_info
The last 3 structures have a dma_adddr_t member defined as the first
member variable. Most of the others also seems valid.
I used this SmPL script to find them:
@e1@
type T;
identifier i;
position p;
attribute name __packed;
@@
T@p {
...
(
atomic_t i;
|
raw_spinlock_t i;
|
struct mutex i;
|
spinlock_t i;
|
dma_addr_t i;
|
phys_addr_t i;
|
size_t i;
|
struct device i;
)
...
}
__packed;
@e2@
type T;
identifier i;
position p;
@@
T@p {
...
(
atomic_t i;
|
raw_spinlock_t i;
|
struct mutex i;
|
spinlock_t i;
|
dma_addr_t i;
|
phys_addr_t i;
|
size_t i;
|
struct device i;
)
...
}
__attribute__((
(
pack
|
__pack__
)
,... ));
@script:python@
ps <<e1.p;
@@
for p in ps:
print p.file, p.line
@script:python@
ps <<e2.p;
@@
for p in ps:
print p.file, p.line
Keisuke
