[PATCH 1/2] scsi: bfa: fix function pointer type mismatch for hcb_qe->cbfn

Arnd Bergmann
2023-06-16T09:22:44Z

From: Arnd Bergmann <arnd@arndb.de>

Some callback functions used here take a boolean argument, others
take a status argument. This breaks KCFI type checking, so clang
now warns about the function pointer cast:

drivers/scsi/bfa/bfad_bsg.c:2138:29: error: cast from 'void (*)(void *, enum bfa_status)' to 'bfa_cb_cbfn_t' (aka 'void (*)(void *, enum bfa_boolean)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]

Assuming the code is actually correct here and the callers always match
the argument types of the callee, rework this to replace the explicit
cast with a union of the two pointer types. This does not change the
behavior of the code, so if something is actually broken here, a larger
rework may be necessary.

Fixes: 37ea0558b87ab ("[SCSI] bfa: Added support to collect and reset fcport stats")
Fixes: 3ec4f2c8bff25 ("[SCSI] bfa: Added support to configure QOS and collect stats.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/scsi/bfa/bfa.h | 9 ++++++++-
drivers/scsi/bfa/bfa_core.c | 4 +---
drivers/scsi/bfa/bfa_ioc.h | 8 ++++++--
drivers/scsi/bfa/bfad_bsg.c | 11 ++++-------
4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/bfa/bfa.h b/drivers/scsi/bfa/bfa.h
index 7bd2ba1ad4d11..f30fe324e6ecc 100644
--- a/drivers/scsi/bfa/bfa.h
+++ b/drivers/scsi/bfa/bfa.h
@@ -20,7 +20,6 @@
struct bfa_s;

typedef void (*bfa_isr_func_t) (struct bfa_s *bfa, struct bfi_msg_s *m);
-typedef void (*bfa_cb_cbfn_status_t) (void *cbarg, bfa_status_t status);

/*
* Interrupt message handlers
@@ -437,4 +436,12 @@ struct bfa_cb_pending_q_s {
(__qe)->data = (__data); \
} while (0)

+#define bfa_pending_q_init_status(__qe, __cbfn, __cbarg, __data) do { \
+ bfa_q_qe_init(&((__qe)->hcb_qe.qe)); \
+ (__qe)->hcb_qe.cbfn_status = (__cbfn); \
+ (__qe)->hcb_qe.cbarg = (__cbarg); \
+ (__qe)->hcb_qe.pre_rmv = BFA_TRUE; \
+ (__qe)->data = (__data); \
+} while (0)
+
#endif /* __BFA_H__ */
diff --git a/drivers/scsi/bfa/bfa_core.c b/drivers/scsi/bfa/bfa_core.c
index 6846ca8f7313c..3438d0b8ba062 100644
--- a/drivers/scsi/bfa/bfa_core.c
+++ b/drivers/scsi/bfa/bfa_core.c
@@ -1907,15 +1907,13 @@ bfa_comp_process(struct bfa_s *bfa, struct list_head *comp_q)
struct list_head *qe;
struct list_head *qen;
struct bfa_cb_qe_s *hcb_qe;
- bfa_cb_cbfn_status_t cbfn;

list_for_each_safe(qe, qen, comp_q) {
hcb_qe = (struct bfa_cb_qe_s *) qe;
if (hcb_qe->pre_rmv) {
/* qe is invalid after return, dequeue before cbfn() */
list_del(qe);
- cbfn = (bfa_cb_cbfn_status_t)(hcb_qe->cbfn);
- cbfn(hcb_qe->cbarg, hcb_qe->fw_status);
+ hcb_qe->cbfn_status(hcb_qe->cbarg, hcb_qe->fw_status);
} else
hcb_qe->cbfn(hcb_qe->cbarg, BFA_TRUE);
}
diff --git a/drivers/scsi/bfa/bfa_ioc.h b/drivers/scsi/bfa/bfa_ioc.h
index 933a1c3890ff5..5e568d6d7b261 100644
--- a/drivers/scsi/bfa/bfa_ioc.h
+++ b/drivers/scsi/bfa/bfa_ioc.h
@@ -361,14 +361,18 @@ struct bfa_reqq_wait_s {
void *cbarg;
};

-typedef void (*bfa_cb_cbfn_t) (void *cbarg, bfa_boolean_t complete);
+typedef void (*bfa_cb_cbfn_t) (void *cbarg, bfa_boolean_t complete);
+typedef void (*bfa_cb_cbfn_status_t) (void *cbarg, bfa_status_t status);

/*
* Generic BFA callback element.
*/
struct bfa_cb_qe_s {
struct list_head qe;
- bfa_cb_cbfn_t cbfn;
+ union {
+ bfa_cb_cbfn_status_t cbfn_status;
+ bfa_cb_cbfn_t cbfn;
+ };
bfa_boolean_t once;
bfa_boolean_t pre_rmv; /* set for stack based qe(s) */
bfa_status_t fw_status; /* to access fw status in comp proc */
diff --git a/drivers/scsi/bfa/bfad_bsg.c b/drivers/scsi/bfa/bfad_bsg.c
index 520f9152f3bf2..c4b78ffb723bd 100644
--- a/drivers/scsi/bfa/bfad_bsg.c
+++ b/drivers/scsi/bfa/bfad_bsg.c
@@ -2135,8 +2135,7 @@ bfad_iocmd_fcport_get_stats(struct bfad_s *bfad, void *cmd)
struct bfa_cb_pending_q_s cb_qe;

init_completion(&fcomp.comp);
- bfa_pending_q_init(&cb_qe, (bfa_cb_cbfn_t)bfad_hcb_comp,
- &fcomp, &iocmd->stats);
+ bfa_pending_q_init_status(&cb_qe, bfad_hcb_comp, &fcomp, &iocmd->stats);
spin_lock_irqsave(&bfad->bfad_lock, flags);
iocmd->status = bfa_fcport_get_stats(&bfad->bfa, &cb_qe);
spin_unlock_irqrestore(&bfad->bfad_lock, flags);
@@ -2159,7 +2158,7 @@ bfad_iocmd_fcport_reset_stats(struct bfad_s *bfad, void *cmd)
struct bfa_cb_pending_q_s cb_qe;

init_completion(&fcomp.comp);
- bfa_pending_q_init(&cb_qe, (bfa_cb_cbfn_t)bfad_hcb_comp, &fcomp, NULL);
+ bfa_pending_q_init_status(&cb_qe, bfad_hcb_comp, &fcomp, NULL);

spin_lock_irqsave(&bfad->bfad_lock, flags);
iocmd->status = bfa_fcport_clear_stats(&bfad->bfa, &cb_qe);
@@ -2443,8 +2442,7 @@ bfad_iocmd_qos_get_stats(struct bfad_s *bfad, void *cmd)
struct bfa_fcport_s *fcport = BFA_FCPORT_MOD(&bfad->bfa);

init_completion(&fcomp.comp);
- bfa_pending_q_init(&cb_qe, (bfa_cb_cbfn_t)bfad_hcb_comp,
- &fcomp, &iocmd->stats);
+ bfa_pending_q_init_status(&cb_qe, bfad_hcb_comp, &fcomp, &iocmd->stats);

spin_lock_irqsave(&bfad->bfad_lock, flags);
WARN_ON(!bfa_ioc_get_fcmode(&bfad->bfa.ioc));
@@ -2474,8 +2472,7 @@ bfad_iocmd_qos_reset_stats(struct bfad_s *bfad, void *cmd)
struct bfa_fcport_s *fcport = BFA_FCPORT_MOD(&bfad->bfa);

init_completion(&fcomp.comp);
- bfa_pending_q_init(&cb_qe, (bfa_cb_cbfn_t)bfad_hcb_comp,
- &fcomp, NULL);
+ bfa_pending_q_init_status(&cb_qe, bfad_hcb_comp, &fcomp, NULL);

spin_lock_irqsave(&bfad->bfad_lock, flags);
WARN_ON(!bfa_ioc_get_fcmode(&bfad->bfa.ioc));
--
2.39.2