diff mbox series

scsi/trace: Use get_unaligned_be*()

Message ID 20191101211447.187151-1-bvanassche@acm.org (mailing list archive)
State Mainlined
Commit b1335f5b0486f61fb66b123b40f8e7a98e49605d
Headers show
Series scsi/trace: Use get_unaligned_be*() | expand

Commit Message

Bart Van Assche Nov. 1, 2019, 9:14 p.m. UTC
This patch fixes an unintended sign extension on left shifts. From Colin
King: "Shifting a u8 left will cause the value to be promoted to an
integer. If the top bit of the u8 is set then the following conversion to
an u64 will sign extend the value causing the upper 32 bits to be set in
the result."

Fix this by using get_unaligned_be*() instead.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: bf8162354233 ("[SCSI] add scsi trace core functions and put trace points")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_trace.c | 109 +++++++++++---------------------------
 1 file changed, 31 insertions(+), 78 deletions(-)

Comments

Martin K. Petersen Nov. 2, 2019, 12:29 a.m. UTC | #1
Bart,

> This patch fixes an unintended sign extension on left shifts. From
> Colin King: "Shifting a u8 left will cause the value to be promoted to
> an integer. If the top bit of the u8 is set then the following
> conversion to an u64 will sign extend the value causing the upper 32
> bits to be set in the result."
>
> Fix this by using get_unaligned_be*() instead.

Applied to 5.5/scsi-queue, thanks!
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_trace.c b/drivers/scsi/scsi_trace.c
index 0f17e7dac1b0..784ed9a32a0d 100644
--- a/drivers/scsi/scsi_trace.c
+++ b/drivers/scsi/scsi_trace.c
@@ -9,7 +9,7 @@ 
 #include <trace/events/scsi.h>
 
 #define SERVICE_ACTION16(cdb) (cdb[1] & 0x1f)
-#define SERVICE_ACTION32(cdb) ((cdb[8] << 8) | cdb[9])
+#define SERVICE_ACTION32(cdb) (get_unaligned_be16(&cdb[8]))
 
 static const char *
 scsi_trace_misc(struct trace_seq *, unsigned char *, int);
@@ -36,17 +36,12 @@  static const char *
 scsi_trace_rw10(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p);
-	sector_t lba = 0, txlen = 0;
+	u32 lba, txlen;
 
-	lba |= (cdb[2] << 24);
-	lba |= (cdb[3] << 16);
-	lba |= (cdb[4] << 8);
-	lba |=  cdb[5];
-	txlen |= (cdb[7] << 8);
-	txlen |=  cdb[8];
+	lba = get_unaligned_be32(&cdb[2]);
+	txlen = get_unaligned_be16(&cdb[7]);
 
-	trace_seq_printf(p, "lba=%llu txlen=%llu protect=%u",
-			 (unsigned long long)lba, (unsigned long long)txlen,
+	trace_seq_printf(p, "lba=%u txlen=%u protect=%u", lba, txlen,
 			 cdb[1] >> 5);
 
 	if (cdb[0] == WRITE_SAME)
@@ -61,19 +56,12 @@  static const char *
 scsi_trace_rw12(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p);
-	sector_t lba = 0, txlen = 0;
+	u32 lba, txlen;
+
+	lba = get_unaligned_be32(&cdb[2]);
+	txlen = get_unaligned_be32(&cdb[6]);
 
-	lba |= (cdb[2] << 24);
-	lba |= (cdb[3] << 16);
-	lba |= (cdb[4] << 8);
-	lba |=  cdb[5];
-	txlen |= (cdb[6] << 24);
-	txlen |= (cdb[7] << 16);
-	txlen |= (cdb[8] << 8);
-	txlen |=  cdb[9];
-
-	trace_seq_printf(p, "lba=%llu txlen=%llu protect=%u",
-			 (unsigned long long)lba, (unsigned long long)txlen,
+	trace_seq_printf(p, "lba=%u txlen=%u protect=%u", lba, txlen,
 			 cdb[1] >> 5);
 	trace_seq_putc(p, 0);
 
@@ -84,23 +72,13 @@  static const char *
 scsi_trace_rw16(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p);
-	sector_t lba = 0, txlen = 0;
+	u64 lba;
+	u32 txlen;
+
+	lba = get_unaligned_be64(&cdb[2]);
+	txlen = get_unaligned_be32(&cdb[10]);
 
-	lba |= ((u64)cdb[2] << 56);
-	lba |= ((u64)cdb[3] << 48);
-	lba |= ((u64)cdb[4] << 40);
-	lba |= ((u64)cdb[5] << 32);
-	lba |= (cdb[6] << 24);
-	lba |= (cdb[7] << 16);
-	lba |= (cdb[8] << 8);
-	lba |=  cdb[9];
-	txlen |= (cdb[10] << 24);
-	txlen |= (cdb[11] << 16);
-	txlen |= (cdb[12] << 8);
-	txlen |=  cdb[13];
-
-	trace_seq_printf(p, "lba=%llu txlen=%llu protect=%u",
-			 (unsigned long long)lba, (unsigned long long)txlen,
+	trace_seq_printf(p, "lba=%llu txlen=%u protect=%u", lba, txlen,
 			 cdb[1] >> 5);
 
 	if (cdb[0] == WRITE_SAME_16)
@@ -115,8 +93,8 @@  static const char *
 scsi_trace_rw32(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p), *cmd;
-	sector_t lba = 0, txlen = 0;
-	u32 ei_lbrt = 0;
+	u64 lba;
+	u32 ei_lbrt, txlen;
 
 	switch (SERVICE_ACTION32(cdb)) {
 	case READ_32:
@@ -136,26 +114,12 @@  scsi_trace_rw32(struct trace_seq *p, unsigned char *cdb, int len)
 		goto out;
 	}
 
-	lba |= ((u64)cdb[12] << 56);
-	lba |= ((u64)cdb[13] << 48);
-	lba |= ((u64)cdb[14] << 40);
-	lba |= ((u64)cdb[15] << 32);
-	lba |= (cdb[16] << 24);
-	lba |= (cdb[17] << 16);
-	lba |= (cdb[18] << 8);
-	lba |=  cdb[19];
-	ei_lbrt |= (cdb[20] << 24);
-	ei_lbrt |= (cdb[21] << 16);
-	ei_lbrt |= (cdb[22] << 8);
-	ei_lbrt |=  cdb[23];
-	txlen |= (cdb[28] << 24);
-	txlen |= (cdb[29] << 16);
-	txlen |= (cdb[30] << 8);
-	txlen |=  cdb[31];
-
-	trace_seq_printf(p, "%s_32 lba=%llu txlen=%llu protect=%u ei_lbrt=%u",
-			 cmd, (unsigned long long)lba,
-			 (unsigned long long)txlen, cdb[10] >> 5, ei_lbrt);
+	lba = get_unaligned_be64(&cdb[12]);
+	ei_lbrt = get_unaligned_be32(&cdb[20]);
+	txlen = get_unaligned_be32(&cdb[28]);
+
+	trace_seq_printf(p, "%s_32 lba=%llu txlen=%u protect=%u ei_lbrt=%u",
+			 cmd, lba, txlen, cdb[10] >> 5, ei_lbrt);
 
 	if (SERVICE_ACTION32(cdb) == WRITE_SAME_32)
 		trace_seq_printf(p, " unmap=%u", cdb[10] >> 3 & 1);
@@ -170,7 +134,7 @@  static const char *
 scsi_trace_unmap(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p);
-	unsigned int regions = cdb[7] << 8 | cdb[8];
+	unsigned int regions = get_unaligned_be16(&cdb[7]);
 
 	trace_seq_printf(p, "regions=%u", (regions - 8) / 16);
 	trace_seq_putc(p, 0);
@@ -182,8 +146,8 @@  static const char *
 scsi_trace_service_action_in(struct trace_seq *p, unsigned char *cdb, int len)
 {
 	const char *ret = trace_seq_buffer_ptr(p), *cmd;
-	sector_t lba = 0;
-	u32 alloc_len = 0;
+	u64 lba;
+	u32 alloc_len;
 
 	switch (SERVICE_ACTION16(cdb)) {
 	case SAI_READ_CAPACITY_16:
@@ -197,21 +161,10 @@  scsi_trace_service_action_in(struct trace_seq *p, unsigned char *cdb, int len)
 		goto out;
 	}
 
-	lba |= ((u64)cdb[2] << 56);
-	lba |= ((u64)cdb[3] << 48);
-	lba |= ((u64)cdb[4] << 40);
-	lba |= ((u64)cdb[5] << 32);
-	lba |= (cdb[6] << 24);
-	lba |= (cdb[7] << 16);
-	lba |= (cdb[8] << 8);
-	lba |=  cdb[9];
-	alloc_len |= (cdb[10] << 24);
-	alloc_len |= (cdb[11] << 16);
-	alloc_len |= (cdb[12] << 8);
-	alloc_len |=  cdb[13];
-
-	trace_seq_printf(p, "%s lba=%llu alloc_len=%u", cmd,
-			 (unsigned long long)lba, alloc_len);
+	lba = get_unaligned_be64(&cdb[2]);
+	alloc_len = get_unaligned_be32(&cdb[10]);
+
+	trace_seq_printf(p, "%s lba=%llu alloc_len=%u", cmd, lba, alloc_len);
 
 out:
 	trace_seq_putc(p, 0);