> -----Original Message----- > From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> > Sent: 2022年1月28日 16:29 > To: Hongxing Zhu <hongxing.zhu@xxxxxxx>; Lucas Stach > <l.stach@xxxxxxxxxxxxxx>; Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>; Rob > Herring <robh@xxxxxxxxxx>; Krzysztof Wilczy?ski <kw@xxxxxxxxx>; Sascha > Hauer <s.hauer@xxxxxxxxxxxxxx>; Pengutronix Kernel Team > <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <festevam@xxxxxxxxx>; > dl-linux-imx <linux-imx@xxxxxxx>; Jason Liu <jason.hui.liu@xxxxxxx> > Cc: linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; Bjorn Helgaas <bhelgaas@xxxxxxxxxx>; Shawn > Guo <shawnguo@xxxxxxxxxx>; Francesco Dolcini > <francesco.dolcini@xxxxxxxxxxx> > Subject: [RFC PATCH] PCI: imx6: Handle the abort from user-space > > From: Jason Liu <jason.hui.liu@xxxxxxx> > > The driver install one hook to handle the external abort, but issue is that if the > abort introduced from user space code, the following code unsigned long instr > = *(unsigned long *)pc; which will created another data-abort(page domain > fault) if CONFIG_CPU_SW_DOMAIN_PAN. > > The patch does not intent to use copy_from_user and then do the hack due to > the security consideration. In fact, we can just return and report the external > abort to user-space. > > Signed-off-by: Jason Liu <jason.hui.liu@xxxxxxx> > Reviewed-by: Richard Zhu <hongxing.zhu@xxxxxxx> > Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx> > --- > We have this patch from NXP downstream kernel [1] in our kernel branch [2] > since a long time, to me it would make sense to upstream it. Any concern? > > [1] > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsource. > codeaurora.org%2Fexternal%2Fimxsupport%2Flinux-imx%2Fcommit%2F%3Fid > %3D62dfb2fb953463dd1b6710567c9e174672a98f24&data=04%7C01%7 > Chongxing.zhu%40nxp.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C68 > 6ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637789553659549198%7 > CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT > iI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Mwhx8DFF7EDJdpqTsHT > %2BBAGzhQadDOqcgJnVjeoi1yk%3D&reserved=0 > [2] > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.tora > dex.com%2Fcgit%2Flinux-toradex.git%2Fcommit%2F%3Fid%3D2b42547cf659f > 979be2defdff6a99f921b33d0f1&data=04%7C01%7Chongxing.zhu%40nx > p.com%7Ccbe193ab4c3e4ad11bcb08d9e2384a1f%7C686ea1d3bc2b4c6fa92c > d99c5c301635%7C0%7C0%7C637789553659549198%7CUnknown%7CTWFp > bGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI > 6Mn0%3D%7C3000&sdata=QEW1frh8WacCzniWo4ng1cy3Z1UZ9uMRFw > GBKuIh7zE%3D&reserved=0 > --- > drivers/pci/controller/dwc/pci-imx6.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > b/drivers/pci/controller/dwc/pci-imx6.c > index 6974bd5aa116..6b178a29e253 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -27,6 +27,7 @@ > #include <linux/resource.h> > #include <linux/signal.h> > #include <linux/types.h> > +#include <linux/uaccess.h> [Richard Zhu] Thanks for your kindly help. This header include is not required actually, please remove it. Best Regards Richard > #include <linux/interrupt.h> > #include <linux/reset.h> > #include <linux/phy/phy.h> > @@ -297,8 +298,15 @@ static int imx6q_pcie_abort_handler(unsigned long > addr, > unsigned int fsr, struct pt_regs *regs) { > unsigned long pc = instruction_pointer(regs); > - unsigned long instr = *(unsigned long *)pc; > - int reg = (instr >> 12) & 15; > + unsigned long instr; > + int reg; > + > + /* if the abort from user-space, just return and report it */ > + if (user_mode(regs)) > + return 1; > + > + instr = *(unsigned long *)pc; > + reg = (instr >> 12) & 15; > > /* > * If the instruction being executed was a read, > -- > 2.25.1
