>
> On 09/01/2019 16:38, Jeffrey Hugo wrote:
>
> >> On 11/12/2018 15:18, Marc Gonzalez wrote:
> >>
> >>> memcpy_fromio() doesn't provide any control over access size.
> >>> For example, on arm64, it is implemented using readb and readq.
> >>> This may trigger a synchronous external abort:
> >>>
> >>> [ 3.729943] Internal error: synchronous external abort: 96000210 [#1]
> PREEMPT SMP
> >>> [ 3.737000] Modules linked in:
> >>> [ 3.744371] CPU: 2 PID: 1 Comm: swapper/0 Tainted: G S
> >>> 4.20.0-
> rc4 #16
> >>> [ 3.747413] Hardware name: Qualcomm Technologies, Inc. MSM8998 v1
> MTP (DT)
> >>> [ 3.755295] pstate: 00000005 (nzcv daif -PAN -UAO)
> >>> [ 3.761978] pc : __memcpy_fromio+0x68/0x80
> >>> [ 3.766718] lr : ufshcd_dump_regs+0x50/0xb0
> >>> [ 3.770767] sp : ffff00000807ba00
> >>> [ 3.774830] x29: ffff00000807ba00 x28: 00000000fffffffb
> >>> [ 3.778344] x27: ffff0000089db068 x26: ffff8000f6e58000
> >>> [ 3.783728] x25: 000000000000000e x24: 0000000000000800
> >>> [ 3.789023] x23: ffff8000f6e587c8 x22: 0000000000000800
> >>> [ 3.794319] x21: ffff000008908368 x20: ffff8000f6e1ab80
> >>> [ 3.799615] x19: 000000000000006c x18: ffffffffffffffff
> >>> [ 3.804910] x17: 0000000000000000 x16: 0000000000000000
> >>> [ 3.810206] x15: ffff000009199648 x14: ffff000089244187
> >>> [ 3.815502] x13: ffff000009244195 x12: ffff0000091ab000
> >>> [ 3.820797] x11: 0000000005f5e0ff x10: ffff0000091998a0
> >>> [ 3.826093] x9 : 0000000000000000 x8 : ffff8000f6e1ac00
> >>> [ 3.831389] x7 : 0000000000000000 x6 : 0000000000000068
> >>> [ 3.836676] x5 : ffff8000f6e1abe8 x4 : 0000000000000000
> >>> [ 3.841971] x3 : ffff00000928c868 x2 : ffff8000f6e1abec
> >>> [ 3.847267] x1 : ffff00000928c868 x0 : ffff8000f6e1abe8
> >>> [ 3.852567] Process swapper/0 (pid: 1, stack limit =
> >>> 0x(____ptrval____))
> >>> [ 3.857900] Call trace:
> >>> [ 3.864473] __memcpy_fromio+0x68/0x80
> >>> [ 3.866683] ufs_qcom_dump_dbg_regs+0x1c0/0x370
> >>> [ 3.870522] ufshcd_print_host_regs+0x168/0x190
> >>> [ 3.874946] ufshcd_init+0xd4c/0xde0
> >>> [ 3.879459] ufshcd_pltfrm_init+0x3c8/0x550
> >>> [ 3.883264] ufs_qcom_probe+0x24/0x60
> >>> [ 3.887188] platform_drv_probe+0x50/0xa0
> >>>
> >>> Assuming aligned 32-bit registers, let's use readl, after making
> >>> sure that 'offset' and 'len' are indeed multiples of 4.
> >>>
> >>> Fixes: ba80917d9932d ("scsi: ufs: ufshcd_dump_regs to use
> >>> memcpy_fromio")
> >>> Signed-off-by: Marc Gonzalez <[email protected]>
> >>> ---
> >>> drivers/scsi/ufs/ufshcd.c | 10 ++++++++--
> >>> 1 file changed, 8 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> >>> index 535180c01ce8..320bbd9849bc 100644
> >>> --- a/drivers/scsi/ufs/ufshcd.c
> >>> +++ b/drivers/scsi/ufs/ufshcd.c
> >>> @@ -112,13 +112,19 @@
> >>> int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len,
> >>> const char *prefix)
> >>> {
> >>> - u8 *regs;
> >>> + u32 *regs;
> >>> + size_t pos;
> >>> +
> >>> + if (offset % 4 != 0 || len % 4 != 0) /* keep readl happy */
> >>> + return -EINVAL;
> >
> > Hmm. It seems like these cases could be handled, but I guess we
> > cannot necessarily assume that reading past the bounds specified by
> > the client is safe, so this seems reasonable.
> >
> >>>
> >>> regs = kzalloc(len, GFP_KERNEL);
> >>> if (!regs)
> >>> return -ENOMEM;
> >>>
> >>> - memcpy_fromio(regs, hba->mmio_base + offset, len);
> >>> + for (pos = 0; pos < len; pos += 4)
> >>> + regs[pos / 4] = ufshcd_readl(hba, offset + pos);
> >>> +
> >>> ufshcd_hex_dump(prefix, regs, len);
> >>> kfree(regs);
> >>>
> >
> > Reviewed-by: Jeffrey Hugo <[email protected]>
>
> James, Martin,
>
> I haven't heard back from Vinayak. (In fact, his last review dates back to
> 2016.
> Should MAINTAINERS be updated? I can send a patch.)
>
> Would you mind taking this patch through the SCSI tree?
>
> Tomas, does "LGTM" translate to Acked-by? :-D
Yes, you can add my Ack.
Thanks
Tomas
