FAILED: patch "[PATCH] perf intel-pt: Ensure never to set 'last_ip' when packet" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jul 22, 2017

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2017-07-22 13:19 UTC #0 lore raw

The patch below does not apply to the 4.4-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 ------------------

Quoted 1 line

From f952eaceb089b691eba7c4e13686e742a8f26bf5 Mon Sep 17 00:00:00 2001

From: Adrian Hunter <[email protected]>
Date: Fri, 26 May 2017 11:17:07 +0300
Subject: [PATCH] perf intel-pt: Ensure never to set 'last_ip' when packet
'count' is zero

Intel PT uses IP compression based on the last IP. For decoding purposes, 'last IP' is not updated when a branch target has been suppressed, which is indicated by IPBytes == 0. IPBytes is stored in the packet 'count', so ensure never to set 'last_ip' when packet 'count' is zero.

Signed-off-by Adrian Hunter <[email protected]>

Cc Andi Kleen <[email protected]>

Cc [email protected]

Link http://lkml.kernel.org/r/[email protected] open here

Signed-off-by Arnaldo Carvalho de Melo <[email protected]>

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +5 -3

index 62e2c2ad3f1d..72b9dc8135a2 100644
@@ -1470,7 +1470,8 @@ static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
 
 		case INTEL_PT_FUP:
 			decoder->pge = true;
-			intel_pt_set_last_ip(decoder);
+			if (decoder->packet.count)
+				intel_pt_set_last_ip(decoder);
 			break;
 
 		case INTEL_PT_MODE_TSX:

@@ -1756,8 +1757,9 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
 
 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
 {
-	return decoder->have_last_ip || decoder->packet.count == 0 ||
-	       decoder->packet.count == 3 || decoder->packet.count == 6;
+	return decoder->packet.count &&
+	       (decoder->have_last_ip || decoder->packet.count == 3 ||
+		decoder->packet.count == 6);
 }
 
 /* Walk PSB+ packets to get in sync. */