diff mbox series

[net,4/6] bnxt_en: Fix receive ring space parameters when XDP is active

Message ID 20241122224547.984808-5-michael.chan@broadcom.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: Bug fixes | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 5 maintainers not CCed: bpf@vger.kernel.org ast@kernel.org hawk@kernel.org john.fastabend@gmail.com daniel@iogearbox.net
netdev/build_clang success Errors and warnings before: 3 this patch: 3
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 Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 4 this patch: 4
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 2 this patch: 2
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-11-23--03-00 (tests: 788)

Commit Message

Michael Chan Nov. 22, 2024, 10:45 p.m. UTC 
From: Shravya KN <shravya.k-n@broadcom.com>

The MTU setting at the time an XDP multi-buffer is attached
determines whether the aggregation ring will be used and the
rx_skb_func handler.  This is done in bnxt_set_rx_skb_mode().

If the MTU is later changed, the aggregation ring setting may need
to be changed and it may become out-of-sync with the settings
initially done in bnxt_set_rx_skb_mode().  This may result in
random memory corruption and crashes as the HW may DMA data larger
than the allocated buffer size, such as:

BUG: kernel NULL pointer dereference, address: 00000000000003c0
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 17 PID: 0 Comm: swapper/17 Kdump: loaded Tainted: G S         OE      6.1.0-226bf9805506 #1
Hardware name: Wiwynn Delta Lake PVT BZA.02601.0150/Delta Lake-Class1, BIOS F0E_3A12 08/26/2021
RIP: 0010:bnxt_rx_pkt+0xe97/0x1ae0 [bnxt_en]
Code: 8b 95 70 ff ff ff 4c 8b 9d 48 ff ff ff 66 41 89 87 b4 00 00 00 e9 0b f7 ff ff 0f b7 43 0a 49 8b 95 a8 04 00 00 25 ff 0f 00 00 <0f> b7 14 42 48 c1 e2 06 49 03 95 a0 04 00 00 0f b6 42 33f
RSP: 0018:ffffa19f40cc0d18 EFLAGS: 00010202
RAX: 00000000000001e0 RBX: ffff8e2c805c6100 RCX: 00000000000007ff
RDX: 0000000000000000 RSI: ffff8e2c271ab990 RDI: ffff8e2c84f12380
RBP: ffffa19f40cc0e48 R08: 000000000001000d R09: 974ea2fcddfa4cbf
R10: 0000000000000000 R11: ffffa19f40cc0ff8 R12: ffff8e2c94b58980
R13: ffff8e2c952d6600 R14: 0000000000000016 R15: ffff8e2c271ab990
FS:  0000000000000000(0000) GS:ffff8e3b3f840000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000003c0 CR3: 0000000e8580a004 CR4: 00000000007706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 __bnxt_poll_work+0x1c2/0x3e0 [bnxt_en]

To address the issue, we now call bnxt_set_rx_skb_mode() within
bnxt_change_mtu() to properly set the AGG rings configuration and
update rx_skb_func based on the new MTU value.
Additionally, BNXT_FLAG_NO_AGG_RINGS is cleared at the beginning of
bnxt_set_rx_skb_mode() to make sure it gets set or cleared based on
the current MTU.

Fixes: 08450ea98ae9 ("bnxt_en: Fix max_mtu setting for multi-buf XDP")
Co-developed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Shravya KN <shravya.k-n@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 3bee485b50f0..b7541156fe46 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4661,7 +4661,7 @@  int bnxt_set_rx_skb_mode(struct bnxt *bp, bool page_mode)
 	struct net_device *dev = bp->dev;
 
 	if (page_mode) {
-		bp->flags &= ~BNXT_FLAG_AGG_RINGS;
+		bp->flags &= ~(BNXT_FLAG_AGG_RINGS | BNXT_FLAG_NO_AGG_RINGS);
 		bp->flags |= BNXT_FLAG_RX_PAGE_MODE;
 
 		if (bp->xdp_prog->aux->xdp_has_frags)
@@ -14740,6 +14740,14 @@  static int bnxt_change_mtu(struct net_device *dev, int new_mtu)
 		bnxt_close_nic(bp, true, false);
 
 	WRITE_ONCE(dev->mtu, new_mtu);
+
+	/* MTU change may change the AGG ring settings if an XDP multi-buffer
+	 * program is attached.  We need to set the AGG rings settings and
+	 * rx_skb_func accordingly.
+	 */
+	if (READ_ONCE(bp->xdp_prog))
+		bnxt_set_rx_skb_mode(bp, true);
+
 	bnxt_set_ring_params(bp);
 
 	if (netif_running(dev))