diff mbox series

[net-next,v2,2/4] bnxt_en: Report the ethtool coredump length after copying the coredump

Message ID 20250417172448.1206107-3-michael.chan@broadcom.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: Update for net-next | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 2 this patch: 2
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 18 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-04-18--09-00 (tests: 916)

Commit Message

Michael Chan April 17, 2025, 5:24 p.m. UTC 
From: Shruti Parab <shruti.parab@broadcom.com>

ethtool first calls .get_dump_flags() to get the dump length.  For
coredump, the driver calls the FW to get the coredump length (L1).  The
min. of L1 and the user specified length is then passed to
.get_dump_data() (L2) to get the coredump.  The actual coredump length
retrieved by the FW (L3) during .get_dump_data() may be smaller than L1.
This length discrepancy will trigger a WARN_ON() in
ethtool_get_dump_data().

ethtool has already vzalloc'ed a buffer with size L1.  Just report
the coredump length as L2 even though the actual coredump length L3
may be smaller.  The extra zero padding does not matter.  This will
prevent the warning that may alarm the user.

For correctness, only do the final length update if there is no error.

Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Signed-off-by: Shruti Parab <shruti.parab@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
index 5576e7cf8463..9b6489e417fc 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_coredump.c
@@ -496,9 +496,16 @@  static int __bnxt_get_coredump(struct bnxt *bp, u16 dump_type, void *buf,
 					  start_utc, coredump.total_segs + 1,
 					  rc);
 	kfree(coredump.data);
-	*dump_len += sizeof(struct bnxt_coredump_record);
-	if (rc == -ENOBUFS)
+	if (!rc) {
+		*dump_len += sizeof(struct bnxt_coredump_record);
+		/* The actual coredump length can be smaller than the FW
+		 * reported length earlier.  Use the ethtool provided length.
+		 */
+		if (buf_len)
+			*dump_len = buf_len;
+	} else if (rc == -ENOBUFS) {
 		netdev_err(bp->dev, "Firmware returned large coredump buffer\n");
+	}
 	return rc;
 }