From a0343e823184070f55364d8359f832dcb33c57c7 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Tue, 9 Dec 2008 23:53:16 +0100
Subject: [PATCH] tracing/function-graph-tracer: add a new .irqentry.text
section
Impact: let the function-graph-tracer be aware of the irq entrypoints
Add a new .irqentry.text section to store the irq entrypoints functions
inside the same section. This way, the tracer will be able to signal
an interrupts triggering on output by recognizing these entrypoints.
Also, make this section recordable for dynamic tracing.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/vmlinux_64.lds.S | 1 +
include/asm-generic/vmlinux.lds.h | 10 ++++++++++
scripts/recordmcount.pl | 1 +
3 files changed, 12 insertions(+)
diff --git a/arch/x86/kernel/vmlinux_64.lds.S b/arch/x86/kernel/vmlinux_64.lds.S
index 46e05447405b4..1a614c0e6befc 100644
--- a/arch/x86/kernel/vmlinux_64.lds.S
+++ b/arch/x86/kernel/vmlinux_64.lds.S
@@ -35,6 +35,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
+ IRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
_etext = .; /* End of text section */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index eba835a2c2cd5..c61fab1dd2f82 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -288,6 +288,16 @@
*(.kprobes.text) \
VMLINUX_SYMBOL(__kprobes_text_end) = .;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#define IRQENTRY_TEXT \
+ ALIGN_FUNCTION(); \
+ VMLINUX_SYMBOL(__irqentry_text_start) = .; \
+ *(.irqentry.text) \
+ VMLINUX_SYMBOL(__irqentry_text_end) = .;
+#else
+#define IRQENTRY_TEXT
+#endif
+
/* Section used for early init (in .S files) */
#define HEAD_TEXT *(.head.text)
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 0b1dc9f9bb068..fe831412bea9c 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -114,6 +114,7 @@ my %text_sections = (
".text" => 1,
".sched.text" => 1,
".spinlock.text" => 1,
+ ".irqentry.text" => 1,
);
$objdump = "objdump" if ((length $objdump) == 0);
--
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