[PATCH 5.16 075/126] net: stmmac: dump gmac4 DMA registers correctly

Greg Kroah-Hartman
2022-02-07T11:59:03Z

From: Camel Guo <camelg@axis.com>

commit 7af037c39b600bac2c716dd1228e8ddbe149573f upstream.

Unlike gmac100, gmac1000, gmac4 has 27 DMA registers and they are
located at DMA_CHAN_BASE_ADDR (0x1100). In order for ethtool to dump
gmac4 DMA registers correctly, this commit checks if a net_device has
gmac4 and uses different logic to dump its DMA registers.

This fixes the following KASAN warning, which can normally be triggered
by a command similar like "ethtool -d eth0":

BUG: KASAN: vmalloc-out-of-bounds in dwmac4_dump_dma_regs+0x6d4/0xb30
Write of size 4 at addr ffffffc010177100 by task ethtool/1839
kasan_report+0x200/0x21c
__asan_report_store4_noabort+0x34/0x60
dwmac4_dump_dma_regs+0x6d4/0xb30
stmmac_ethtool_gregs+0x110/0x204
ethtool_get_regs+0x200/0x4b0
dev_ethtool+0x1dac/0x3800
dev_ioctl+0x7c0/0xb50
sock_ioctl+0x298/0x6c4
...

Fixes: fbf68229ffe7 ("net: stmmac: unify registers dumps methods")
Signed-off-by: Camel Guo <camelg@axis.com>
Link: https://lore.kernel.org/r/20220131083841.3346801-1-camel.guo@axis.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h | 1 +
drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 19 +++++++++++++++++--
2 files changed, 18 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
@@ -150,6 +150,7 @@

#define NUM_DWMAC100_DMA_REGS 9
#define NUM_DWMAC1000_DMA_REGS 23
+#define NUM_DWMAC4_DMA_REGS 27

void dwmac_enable_dma_transmission(void __iomem *ioaddr);
void dwmac_enable_dma_irq(void __iomem *ioaddr, u32 chan, bool rx, bool tx);
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -21,10 +21,18 @@
#include "dwxgmac2.h"

#define REG_SPACE_SIZE 0x1060
+#define GMAC4_REG_SPACE_SIZE 0x116C
#define MAC100_ETHTOOL_NAME "st_mac100"
#define GMAC_ETHTOOL_NAME "st_gmac"
#define XGMAC_ETHTOOL_NAME "st_xgmac"

+/* Same as DMA_CHAN_BASE_ADDR defined in dwmac4_dma.h
+ *
+ * It is here because dwmac_dma.h and dwmac4_dam.h can not be included at the
+ * same time due to the conflicting macro names.
+ */
+#define GMAC4_DMA_CHAN_BASE_ADDR 0x00001100
+
#define ETHTOOL_DMA_OFFSET 55

struct stmmac_stats {
@@ -435,6 +443,8 @@ static int stmmac_ethtool_get_regs_len(s

if (priv->plat->has_xgmac)
return XGMAC_REGSIZE * 4;
+ else if (priv->plat->has_gmac4)
+ return GMAC4_REG_SPACE_SIZE;
return REG_SPACE_SIZE;
}

@@ -447,8 +457,13 @@ static void stmmac_ethtool_gregs(struct
stmmac_dump_mac_regs(priv, priv->hw, reg_space);
stmmac_dump_dma_regs(priv, priv->ioaddr, reg_space);

- if (!priv->plat->has_xgmac) {
- /* Copy DMA registers to where ethtool expects them */
+ /* Copy DMA registers to where ethtool expects them */
+ if (priv->plat->has_gmac4) {
+ /* GMAC4 dumps its DMA registers at its DMA_CHAN_BASE_ADDR */
+ memcpy(&reg_space[ETHTOOL_DMA_OFFSET],
+ &reg_space[GMAC4_DMA_CHAN_BASE_ADDR / 4],
+ NUM_DWMAC4_DMA_REGS * 4);
+ } else if (!priv->plat->has_xgmac) {
memcpy(&reg_space[ETHTOOL_DMA_OFFSET],
&reg_space[DMA_BUS_MODE / 4],
NUM_DWMAC1000_DMA_REGS * 4);