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FAILED: patch "[PATCH] tty: n_gsm: Fix packet data hex dump output" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message Jun 7, 2022

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The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 925ea0fa5277c1e6bb9e51955ef34eea9736c3d7 Mon Sep 17 00:00:00 2001
From: Tony Lindgren <[email protected]>
Date: Thu, 12 May 2022 16:15:06 +0300
Subject: [PATCH] tty: n_gsm: Fix packet data hex dump output

The module param debug for n_gsm uses KERN_INFO level, but the hexdump now uses KERN_DEBUG level. This started after commit 091cb0994edd ("lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds"). We now use dynamic_hex_dump() unless DEBUG is set.

This causes no packets to be seen with modprobe n_gsm debug=0x1f unlike earlier. Let's fix this by adding gsm_hex_dump_bytes() that calls print_hex_dump() with KERN_INFO to match what n_gsm is doing with the other debug related output.

Fixes 091cb0994edd ("lib/hexdump: make print_hex_dump_bytes() a nop on !DEBUG builds")
Cc Stephen Boyd <[email protected]>
Signed-off-by Tony Lindgren <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/tty/n_gsm.c +23 -8
index 8fc05b60ac7f..137eebdcfda9 100644
@@ -444,6 +444,25 @@ static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
 	return modembits;
 }
 
+static void gsm_hex_dump_bytes(const char *fname, const u8 *data,
+			       unsigned long len)
+{
+	char *prefix;
+
+	if (!fname) {
+		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, data, len,
+			       true);
+		return;
+	}
+
+	prefix = kasprintf(GFP_KERNEL, "%s: ", fname);
+	if (!prefix)
+		return;
+	print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len,
+		       true);
+	kfree(prefix);
+}
+
 /**
  *	gsm_print_packet	-	display a frame for debug
  *	@hdr: header to print before decode

@@ -508,7 +527,7 @@ static void gsm_print_packet(const char *hdr, int addr, int cr,
 	else
 		pr_cont("(F)");
 
-	print_hex_dump_bytes("", DUMP_PREFIX_NONE, data, dlen);
+	gsm_hex_dump_bytes(NULL, data, dlen);
 }
 
 

@@ -698,9 +717,7 @@ static void gsm_data_kick(struct gsm_mux *gsm, struct gsm_dlci *dlci)
 		}
 
 		if (debug & 4)
-			print_hex_dump_bytes("gsm_data_kick: ",
-					     DUMP_PREFIX_OFFSET,
-					     gsm->txframe, len);
+			gsm_hex_dump_bytes(__func__, gsm->txframe, len);
 		if (gsmld_output(gsm, gsm->txframe, len) <= 0)
 			break;
 		/* FIXME: Can eliminate one SOF in many more cases */

@@ -2444,8 +2461,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
 		return -ENOSPC;
 	}
 	if (debug & 4)
-		print_hex_dump_bytes("gsmld_output: ", DUMP_PREFIX_OFFSET,
-				     data, len);
+		gsm_hex_dump_bytes(__func__, data, len);
 	return gsm->tty->ops->write(gsm->tty, data, len);
 }
 

@@ -2521,8 +2537,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	char flags = TTY_NORMAL;
 
 	if (debug & 4)
-		print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET,
-				     cp, count);
+		gsm_hex_dump_bytes(__func__, cp, count);
 
 	for (; count; count--, cp++) {
 		if (fp)