scsi: ufs: Use explicit access size in ufshcd_dump_regs

mwgonzalez · martinkpetersen · commit d67247566450 · 2019-01-22T21:11:40.000-05:00
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 torvalds#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: ba80917 ("scsi: ufs: ufshcd_dump_regs to use memcpy_fromio") Cc: <stable@vger.kernel.org> Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr> Acked-by: Tomas Winkler <tomas.winkler@intel.com> Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Tested-by: Evan Green <evgreen@chromium.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
@@ -108,13 +108,19 @@
 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);
 
