On 1/9/2019 5:42 AM, Marc Gonzalez wrote:
Bjorn, Andy, Jeffrey,
What do you think about the patch below?
Regards.
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 <marc.w.gonzalez@xxxxxxx>
---
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 <jhugo@xxxxxxxxxxxxxx>
--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
