[PATCH 12/15] ftrace/recordmcount: Add helper function get_sym_str_and_relp()

Steven Rostedt
2011-05-18T16:10:30Z

[-- Attachment #1: 0012-ftrace-recordmcount-Add-helper-function-get_sym_str_.patch --]
[-- Type: text/plain, Size: 4622 bytes --]

From: Steven Rostedt <srostedt@redhat.com>

The code to get the symbol, string, and relp pointers in the two functions
sift_rel_mcount() and nop_mcount() are identical and also non-trivial.
Moving this duplicate code into a single helper function makes the code
easier to read and more maintainable.

Cc: John Reiser <jreiser@bitwagon.com>
Link: http://lkml.kernel.org/r/20110421023739.723658553@goodmis.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
scripts/recordmcount.h | 67 ++++++++++++++++++++++++++---------------------
1 files changed, 37 insertions(+), 30 deletions(-)

diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
index deb6a51..3c00fab 100644
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -29,6 +29,7 @@
#undef has_rel_mcount
#undef tot_relsize
#undef get_mcountsym
+#undef get_sym_str_and_relp
#undef do_func
#undef Elf_Addr
#undef Elf_Ehdr
@@ -56,6 +57,7 @@
# define __has_rel_mcount __has64_rel_mcount
# define has_rel_mcount has64_rel_mcount
# define tot_relsize tot64_relsize
+# define get_sym_str_and_relp get_sym_str_and_relp_64
# define do_func do64
# define get_mcountsym get_mcountsym_64
# define is_fake_mcount is_fake_mcount64
@@ -86,6 +88,7 @@
# define __has_rel_mcount __has32_rel_mcount
# define has_rel_mcount has32_rel_mcount
# define tot_relsize tot32_relsize
+# define get_sym_str_and_relp get_sym_str_and_relp_32
# define do_func do32
# define get_mcountsym get_mcountsym_32
# define is_fake_mcount is_fake_mcount32
@@ -260,6 +263,29 @@ static unsigned get_mcountsym(Elf_Sym const *const sym0,
return mcountsym;
}

+static void get_sym_str_and_relp(Elf_Shdr const *const relhdr,
+ Elf_Ehdr const *const ehdr,
+ Elf_Sym const **sym0,
+ char const **str0,
+ Elf_Rel const **relp)
+{
+ Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ + (void *)ehdr);
+ unsigned const symsec_sh_link = w(relhdr->sh_link);
+ Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
+ Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
+ Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
+ + (void *)ehdr);
+
+ *sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
+ + (void *)ehdr);
+
+ *str0 = (char const *)(_w(strsec->sh_offset)
+ + (void *)ehdr);
+
+ *relp = rel0;
+}
+
/*
* Look at the relocations in order to find the calls to mcount.
* Accumulate the section offsets that are found, and their relocation info,
@@ -276,26 +302,16 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
{
uint_t *const mloc0 = mlocp;
Elf_Rel *mrelp = *mrelpp;
- Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
- + (void *)ehdr);
- unsigned const symsec_sh_link = w(relhdr->sh_link);
- Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
- Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
- + (void *)ehdr);
-
- Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
- char const *const str0 = (char const *)(_w(strsec->sh_offset)
- + (void *)ehdr);
-
- Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
- + (void *)ehdr);
+ Elf_Sym const *sym0;
+ char const *str0;
+ Elf_Rel const *relp;
unsigned rel_entsize = _w(relhdr->sh_entsize);
unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
- Elf_Rel const *relp = rel0;
-
unsigned mcountsym = 0;
unsigned t;

+ get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
+
for (t = nrel; t; --t) {
if (!mcountsym)
mcountsym = get_mcountsym(sym0, relp, str0);
@@ -331,27 +347,18 @@ static void nop_mcount(Elf_Shdr const *const relhdr,
{
Elf_Shdr *const shdr0 = (Elf_Shdr *)(_w(ehdr->e_shoff)
+ (void *)ehdr);
- unsigned const symsec_sh_link = w(relhdr->sh_link);
- Elf_Shdr const *const symsec = &shdr0[symsec_sh_link];
- Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symsec->sh_offset)
- + (void *)ehdr);
-
- Elf_Shdr const *const strsec = &shdr0[w(symsec->sh_link)];
- char const *const str0 = (char const *)(_w(strsec->sh_offset)
- + (void *)ehdr);
-
- Elf_Rel const *const rel0 = (Elf_Rel const *)(_w(relhdr->sh_offset)
- + (void *)ehdr);
+ Elf_Sym const *sym0;
+ char const *str0;
+ Elf_Rel const *relp;
+ Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
unsigned rel_entsize = _w(relhdr->sh_entsize);
unsigned const nrel = _w(relhdr->sh_size) / rel_entsize;
- Elf_Rel const *relp = rel0;
-
- Elf_Shdr const *const shdr = &shdr0[w(relhdr->sh_info)];
-
unsigned mcountsym = 0;
unsigned t;
int once = 0;

+ get_sym_str_and_relp(relhdr, ehdr, &sym0, &str0, &relp);
+
for (t = nrel; t; --t) {
int ret = -1;

--
1.7.4.4