On Tue 22 Jan 09:29 PST 2019, 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")
> Acked-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> Reviewed-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@xxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
> 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;
>
> 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);
>
> --
> 2.17.1
