[PATCH 11/15] ftrace/recordmcount: Remove duplicate code to find mcount symbol

Steven Rostedt
2011-05-18T16:10:29Z

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From: Steven Rostedt <srostedt@redhat.com>

The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol
number is identical. Replace the two locations with a call to a function
that does the work.

Cc: John Reiser <jreiser@bitwagon.com>
Link: http://lkml.kernel.org/r/20110421023739.488093407@goodmis.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
scripts/recordmcount.h | 51 +++++++++++++++++++++++++----------------------
1 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index 22033d5..deb6a51 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -28,6 +28,7 @@
#undef __has_rel_mcount
#undef has_rel_mcount
#undef tot_relsize
+#undef get_mcountsym
#undef do_func
#undef Elf_Addr
#undef Elf_Ehdr
@@ -56,6 +57,7 @@
# define has_rel_mcount has64_rel_mcount
# define tot_relsize tot64_relsize
# define do_func do64
+# define get_mcountsym get_mcountsym_64
# define is_fake_mcount is_fake_mcount64
# define fn_is_fake_mcount fn_is_fake_mcount64
# define MIPS_is_fake_mcount MIPS64_is_fake_mcount
@@ -85,6 +87,7 @@
# define has_rel_mcount has32_rel_mcount
# define tot_relsize tot32_relsize
# define do_func do32
+# define get_mcountsym get_mcountsym_32
# define is_fake_mcount is_fake_mcount32
# define fn_is_fake_mcount fn_is_fake_mcount32
# define MIPS_is_fake_mcount MIPS32_is_fake_mcount
@@ -237,6 +240,26 @@ static void append_func(Elf_Ehdr *const ehdr,
uwrite(fd_map, ehdr, sizeof(*ehdr));
}

+static unsigned get_mcountsym(Elf_Sym const *const sym0,
+ Elf_Rel const *relp,
+ char const *const str0)
+{
+ unsigned mcountsym = 0;
+
+ Elf_Sym const *const symp =
+ &sym0[Elf_r_sym(relp)];
+ char const *symname = &str0[w(symp->st_name)];
+ char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
+
+ if (symname[0] == '.')
+ ++symname; /* ppc64 hack */
+ if (strcmp(mcount, symname) == 0 ||
+ (altmcount && strcmp(altmcount, symname) == 0))
+ mcountsym = Elf_r_sym(relp);
+
+ return mcountsym;
+}
+
/*
* Look at the relocations in order to find the calls to mcount.
* Accumulate the section offsets that are found, and their relocation info,
@@ -274,18 +297,8 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
unsigned t;

for (t = nrel; t; --t) {
- if (!mcountsym) {
- Elf_Sym const *const symp =
- &sym0[Elf_r_sym(relp)];
- char const *symname = &str0[w(symp->st_name)];
- char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
-
- if (symname[0] == '.')
- ++symname; /* ppc64 hack */
- if (strcmp(mcount, symname) == 0 ||
- (altmcount && strcmp(altmcount, symname) == 0))
- mcountsym = Elf_r_sym(relp);
- }
+ if (!mcountsym)
+ mcountsym = get_mcountsym(sym0, relp, str0);

if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
uint_t const addend = _w(_w(relp->r_offset) - recval);
@@ -342,18 +355,8 @@ static void nop_mcount(Elf_Shdr const *const relhdr,
for (t = nrel; t; --t) {
int ret = -1;

- if (!mcountsym) {
- Elf_Sym const *const symp =
- &sym0[Elf_r_sym(relp)];
- char const *symname = &str0[w(symp->st_name)];
- char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
-
- if (symname[0] == '.')
- ++symname; /* ppc64 hack */
- if (strcmp(mcount, symname) == 0 ||
- (altmcount && strcmp(altmcount, symname) == 0))
- mcountsym = Elf_r_sym(relp);
- }
+ if (!mcountsym)
+ mcountsym = get_mcountsym(sym0, relp, str0);

if (mcountsym == Elf_r_sym(relp) && !is_fake_mcount(relp)) {
if (make_nop)
--
1.7.4.4