RE: [PATCH net-next] net: stmmac: support FPE link partner hand-shaking procedure

On Thu, 25 March 2021, 11:13PM +800, Marek Szyprowski wrote: 

This patch landed in today's linux-next as commit 5a5586112b92 ("net:
stmmac: support FPE link partner hand-shaking procedure"). It causes the
following NULL pointer dereference issue on various Amlogic SoC based
boards:

  meson8b-dwmac ff3f0000.ethernet eth0: PHY [0.0:00] driver [RTL8211F
Gigabit Ethernet] (irq=35)
  meson8b-dwmac ff3f0000.ethernet eth0: No Safety Features support
found
  meson8b-dwmac ff3f0000.ethernet eth0: PTP not supported by HW
  meson8b-dwmac ff3f0000.ethernet eth0: configuring for phy/rgmii link
mode
  Unable to handle kernel NULL pointer dereference at virtual address
0000000000000001
  Mem abort info:
...
  user pgtable: 4k pages, 48-bit VAs, pgdp=00000000044eb000
  [0000000000000001] pgd=0000000000000000, p4d=0000000000000000
  Internal error: Oops: 96000004 [#1] PREEMPT SMP
  Modules linked in: dw_hdmi_i2s_audio dw_hdmi_cec meson_gxl realtek
meson_gxbb_wdt snd_soc_meson_axg_sound_card dwmac_generic
axg_audio
meson_dw_hdmi crct10dif_ce snd_soc_meson_card_utils
snd_soc_meson_axg_tdmout panfrost rc_odroid gpu_sched
reset_meson_audio_arb meson_ir snd_soc_meson_g12a_tohdmitx
snd_soc_meson_axg_frddr sclk_div clk_phase snd_soc_meson_codec_glue
dwmac_meson8b snd_soc_meson_axg_fifo stmmac_platform meson_rng
meson_drm
stmmac rtc_meson_vrtc rng_core meson_canvas pwm_meson dw_hdmi
mdio_mux_meson_g12a pcs_xpcs snd_soc_meson_axg_tdm_interface
snd_soc_meson_axg_tdm_formatter nvmem_meson_efuse
display_connector
  CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.12.0-rc4-next-20210325+
#2747
  Hardware name: Hardkernel ODROID-C4 (DT)
  Workqueue: events_power_efficient phylink_resolve
  pstate: 20400009 (nzCv daif +PAN -UAO -TCO BTYPE=--)
  pc : stmmac_mac_link_up+0x14c/0x348 [stmmac]
  lr : stmmac_mac_link_up+0x284/0x348 [stmmac]
...
  Call trace:
   stmmac_mac_link_up+0x14c/0x348 [stmmac]
   phylink_resolve+0x104/0x420
   process_one_work+0x2a8/0x718
   worker_thread+0x48/0x460
   kthread+0x134/0x160
   ret_from_fork+0x10/0x18
  Code: b971ba60 350007c0 f958c260 f9402000 (39400401)
  ---[ end trace 0c9deb6c510228aa ]---


Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Sorry for that, we will submit a fix for this.

VK