diff mbox series

[net-next,v2,11/15] ice: cleanup allocations in ice_ptp_alloc_tx_tracker

Message ID 20221207210937.1099650-12-anthony.l.nguyen@intel.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2022-12-07 (ice) | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 28 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Tony Nguyen Dec. 7, 2022, 9:09 p.m. UTC 
From: Jacob Keller <jacob.e.keller@intel.com>

The ice_ptp_alloc_tx_tracker function must allocate the timestamp array and
the bitmap for tracking the currently in use indexes. A future change is
going to add yet another allocation to this function.

If these allocations fail we need to ensure that we properly cleanup and
ensure that the pointers in the ice_ptp_tx structure are NULL.

Simplify this logic by allocating to local variables first. If any
allocation fails, then free everything and exit. Only update the ice_ptp_tx
structure if all allocations succeed.

This ensures that we have no side effects on the Tx structure unless all
allocations have succeeded. Thus, no code will see an invalid pointer and
we don't need to re-assign NULL on cleanup.

This is safe because kernel "free" functions are designed to be NULL safe
and perform no action if passed a NULL pointer. Thus its safe to simply
always call kfree or bitmap_free even if one of those pointers was NULL.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index dffcd50bac3f..fbafa82ea1ed 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -794,17 +794,21 @@  static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 static int
 ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 {
-	tx->tstamps = kcalloc(tx->len, sizeof(*tx->tstamps), GFP_KERNEL);
-	if (!tx->tstamps)
-		return -ENOMEM;
+	struct ice_tx_tstamp *tstamps;
+	unsigned long *in_use;
+
+	tstamps = kcalloc(tx->len, sizeof(*tstamps), GFP_KERNEL);
+	in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
+
+	if (!tstamps || !in_use) {
+		kfree(tstamps);
+		bitmap_free(in_use);
 
-	tx->in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
-	if (!tx->in_use) {
-		kfree(tx->tstamps);
-		tx->tstamps = NULL;
 		return -ENOMEM;
 	}
 
+	tx->tstamps = tstamps;
+	tx->in_use = in_use;
 	tx->init = 1;
 	tx->link_down = 0;
 	tx->calibrating = 0;