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From: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Thu, 24 Feb 2022 11:06:54 +0530
Subject: perf: Add irq and exception return branch types
Git-commit: cedd3614e5d9c80908099c19f8716714ce0610b1
Patch-mainline: v5.18-rc1
References: jsc#PED-1754 (dependent patch)

This expands generic branch type classification by adding two more entries
there in i.e irq and exception return. Also updates the x86 implementation
to process X86_BR_IRET and X86_BR_IRQ records as appropriate. This changes
branch types reported to user space on x86 platform but it should not be a
problem. The possible scenarios and impacts are enumerated here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1645681014-3346-1-git-send-email-anshuman.khandual@arm.com

Signed-off-by: Tony Jones <tonyj@suse.de>
---
 arch/x86/events/intel/lbr.c           | 4 ++--
 include/uapi/linux/perf_event.h       | 2 ++
 tools/include/uapi/linux/perf_event.h | 2 ++
 tools/perf/util/branch.c              | 4 +++-
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 669c2be14784..fe1742c4ca49 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -1329,10 +1329,10 @@ static int branch_map[X86_BR_TYPE_MAP_MAX] = {
 	PERF_BR_SYSCALL,	/* X86_BR_SYSCALL */
 	PERF_BR_SYSRET,		/* X86_BR_SYSRET */
 	PERF_BR_UNKNOWN,	/* X86_BR_INT */
-	PERF_BR_UNKNOWN,	/* X86_BR_IRET */
+	PERF_BR_ERET,		/* X86_BR_IRET */
 	PERF_BR_COND,		/* X86_BR_JCC */
 	PERF_BR_UNCOND,		/* X86_BR_JMP */
-	PERF_BR_UNKNOWN,	/* X86_BR_IRQ */
+	PERF_BR_IRQ,		/* X86_BR_IRQ */
 	PERF_BR_IND_CALL,	/* X86_BR_IND_CALL */
 	PERF_BR_UNKNOWN,	/* X86_BR_ABORT */
 	PERF_BR_UNKNOWN,	/* X86_BR_IN_TX */
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 1b65042ab1db..7dc71768749d 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -251,6 +251,8 @@ enum {
 	PERF_BR_SYSRET		= 8,	/* syscall return */
 	PERF_BR_COND_CALL	= 9,	/* conditional function call */
 	PERF_BR_COND_RET	= 10,	/* conditional function return */
+	PERF_BR_ERET		= 11,	/* exception return */
+	PERF_BR_IRQ		= 12,	/* irq */
 	PERF_BR_MAX,
 };
 
diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
index 4cd39aaccbe7..d1324c427e8b 100644
--- a/tools/include/uapi/linux/perf_event.h
+++ b/tools/include/uapi/linux/perf_event.h
@@ -251,6 +251,8 @@ enum {
 	PERF_BR_SYSRET		= 8,	/* syscall return */
 	PERF_BR_COND_CALL	= 9,	/* conditional function call */
 	PERF_BR_COND_RET	= 10,	/* conditional function return */
+	PERF_BR_ERET		= 11,	/* exception return */
+	PERF_BR_IRQ		= 12,	/* irq */
 	PERF_BR_MAX,
 };
 
diff --git a/tools/perf/util/branch.c b/tools/perf/util/branch.c
index 2285b1eb3128..a9a909db8cc7 100644
--- a/tools/perf/util/branch.c
+++ b/tools/perf/util/branch.c
@@ -49,7 +49,9 @@ const char *branch_type_name(int type)
 		"SYSCALL",
 		"SYSRET",
 		"COND_CALL",
-		"COND_RET"
+		"COND_RET",
+		"ERET",
+		"IRQ"
 	};
 
 	if (type >= 0 && type < PERF_BR_MAX)