When CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is enabled, each function is
added to its own new section called .text.functionname.
As described in vmlinux.lds.h, "those enabling
LD_DEAD_CODE_DATA_ELIMINATION must ensure they don't have conflicting
section names, and must pull in .text.[0-9a-zA-Z_]*", add a similar
pattern matching to recordmcount script for section detection.
To simplify the basic C implementation, replace the regex with a string
match on the prefix and a single character match following the '.text.'
prefix.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
---
scripts/Makefile | 5 +++++
scripts/recordmcount.c | 26 +++++++++++++++++++++++++-
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/scripts/Makefile b/scripts/Makefile
index 1d80897..9b88250 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -23,6 +23,11 @@ hostprogs-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
HOSTCFLAGS_sortextable.o = -I$(srctree)/tools/include
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
+
+ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+HOSTCFLAGS_recordmcount.o = -DMCOUNT_INCLUDE_FUNCTION_SECTIONS
+endif
+
HOSTLOADLIBES_sign-file = -lcrypto
HOSTLOADLIBES_extract-cert = -lcrypto
diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index aeb3422..bb517ef 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -32,6 +32,7 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <ctype.h>
/*
* glibc synced up and added the metag number but didn't add the relocations.
@@ -408,9 +409,31 @@ static uint32_t (*w)(uint32_t);
static uint32_t (*w2)(uint16_t);
/* Names of the sections that could contain calls to mcount. */
+#ifdef MCOUNT_INCLUDE_FUNCTION_SECTIONS
+static int
+is_mcounted_function_section_name(char const *const txtname)
+{
+ const size_t len = strlen(".text.");
+
+ return strncmp(".text.", txtname, len) == 0 &&
+ strlen(txtname) > len &&
+ (isalnum(txtname[len]) || txtname[len] == '_');
+}
+#else
+static int
+is_mcounted_function_section_name(char const *const txtname)
+{
+ return 0;
+}
+#endif
+
+
static int
is_mcounted_section_name(char const *const txtname)
{
+ int ffunc_section =
+ is_mcounted_function_section_name(txtname);
+
return strcmp(".text", txtname) == 0 ||
strcmp(".ref.text", txtname) == 0 ||
strcmp(".sched.text", txtname) == 0 ||
@@ -419,7 +442,8 @@ is_mcounted_section_name(char const *const txtname)
strcmp(".softirqentry.text", txtname) == 0 ||
strcmp(".kprobes.text", txtname) == 0 ||
strcmp(".cpuidle.text", txtname) == 0 ||
- strcmp(".text.unlikely", txtname) == 0;
+ strcmp(".text.unlikely", txtname) == 0 ||
+ ffunc_section;
}
/* 32 bit and 64 bit are very similar */
--
2.7.4
--
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