From: Matt Helsley <mhelsley@vmware.com>
To: <linux-kernel@vger.kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Sami Tolvanen <samitolvanen@google.com>,
Julien Thierry <jthierry@redhat.com>,
Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
Matt Helsley <mhelsley@vmware.com>
Subject: [RFC][PATCH v4 08/32] objtool: mcount: Walk objtool Elf structs in find_secsym_ndx
Date: Tue, 2 Jun 2020 12:50:01 -0700 [thread overview]
Message-ID: <23497cb675be990627fa76eed26c1385cb0f5826.1591125127.git.mhelsley@vmware.com> (raw)
In-Reply-To: <cover.1591125127.git.mhelsley@vmware.com>
Rather than using indices into raw ELF32/64 tables mapped for the
wrapper, use the objtool functions to find the a suitable symbol
in the given text section.
Also take advantage of this commit to rename the function to
something that reads more easily.
Signed-off-by: Matt Helsley <mhelsley@vmware.com>
---
tools/objtool/recordmcount.c | 2 ++
tools/objtool/recordmcount.h | 42 ++++++++++++++++--------------------
2 files changed, 21 insertions(+), 23 deletions(-)
diff --git a/tools/objtool/recordmcount.c b/tools/objtool/recordmcount.c
index f20582ac99e2..843027a46e1b 100644
--- a/tools/objtool/recordmcount.c
+++ b/tools/objtool/recordmcount.c
@@ -422,6 +422,8 @@ static int is_mcounted_section_name(char const *const txtname)
strcmp(".cpuidle.text", txtname) == 0;
}
+static const unsigned int missing_sym = (unsigned int)-1;
+
/* 32 bit and 64 bit are very similar */
#include "recordmcount.h"
#define RECORD_MCOUNT_64
diff --git a/tools/objtool/recordmcount.h b/tools/objtool/recordmcount.h
index b487308992ce..dba1c385106f 100644
--- a/tools/objtool/recordmcount.h
+++ b/tools/objtool/recordmcount.h
@@ -24,7 +24,7 @@
#undef mcount_adjust
#undef sift_rel_mcount
#undef nop_mcount
-#undef find_secsym_ndx
+#undef find_section_sym_index
#undef has_rel_mcount
#undef tot_relsize
#undef get_mcountsym
@@ -53,7 +53,7 @@
# define append_func append64
# define sift_rel_mcount sift64_rel_mcount
# define nop_mcount nop_mcount_64
-# define find_secsym_ndx find64_secsym_ndx
+# define find_section_sym_index find64_section_sym_index
# define has_rel_mcount has64_rel_mcount
# define tot_relsize tot64_relsize
# define get_sym_str_and_relp get_sym_str_and_relp_64
@@ -85,7 +85,7 @@
# define append_func append32
# define sift_rel_mcount sift32_rel_mcount
# define nop_mcount nop_mcount_32
-# define find_secsym_ndx find32_secsym_ndx
+# define find_section_sym_index find32_section_sym_index
# define has_rel_mcount has32_rel_mcount
# define tot_relsize tot32_relsize
# define get_sym_str_and_relp get_sym_str_and_relp_32
@@ -427,38 +427,36 @@ static int nop_mcount(const struct section * const rels,
* Num: Value Size Type Bind Vis Ndx Name
* 2: 00000000 0 SECTION LOCAL DEFAULT 1
*/
-static int find_secsym_ndx(unsigned const txtndx,
+static int find_section_sym_index(unsigned const txtndx,
char const *const txtname,
uint_t *const recvalp,
unsigned int *sym_index,
- Elf_Shdr const *const symhdr,
Elf_Ehdr const *const ehdr)
{
- Elf_Sym const *const sym0 = (Elf_Sym const *)(_w(symhdr->sh_offset)
- + (void *)ehdr);
- unsigned const nsym = _w(symhdr->sh_size) / _w(symhdr->sh_entsize);
- Elf_Sym const *symp;
- unsigned t;
+ struct symbol *sym;
+ struct section *txts = find_section_by_index(lf, txtndx);
- for (symp = sym0, t = nsym; t; --t, ++symp) {
- unsigned int const st_bind = ELF_ST_BIND(symp->st_info);
+ if (!txts) {
+ fprintf(stderr, "Cannot find section %u: %s.\n",
+ txtndx, txtname);
+ return missing_sym;
+ }
- if (txtndx == w2(symp->st_shndx)
- /* avoid STB_WEAK */
- && (STB_LOCAL == st_bind || STB_GLOBAL == st_bind)) {
+ list_for_each_entry(sym, &txts->symbol_list, list) {
+ if ((sym->bind == STB_LOCAL) || (sym->bind == STB_GLOBAL)) {
/* function symbols on ARM have quirks, avoid them */
if (w2(ehdr->e_machine) == EM_ARM
- && ELF_ST_TYPE(symp->st_info) == STT_FUNC)
+ && sym->type == STT_FUNC)
continue;
- *recvalp = _w(symp->st_value);
- *sym_index = symp - sym0;
+ *recvalp = sym->sym.st_value;
+ *sym_index = sym->idx;
return 0;
}
}
fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
txtndx, txtname);
- return -1;
+ return missing_sym;
}
static char const *has_rel_mcount(const struct section * const rels)
@@ -540,10 +538,8 @@ static int do_func(Elf_Ehdr *const ehdr,
uint_t recval = 0;
symsec_sh_link = sec->sh.sh_link;
- result = find_secsym_ndx(sec->sh.sh_info, txtname,
- &recval, &recsym,
- &shdr0[symsec_sh_link],
- ehdr);
+ result = find_section_sym_index(sec->sh.sh_info,
+ txtname, &recval, &recsym, ehdr);
if (result)
goto out;
--
2.20.1
next prev parent reply other threads:[~2020-06-02 19:52 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 19:49 [RFC][PATCH v4 00/32] objtool: Make recordmcount a subcommand Matt Helsley
2020-06-02 19:49 ` [RFC][PATCH v4 01/32] objtool: Prepare to merge recordmcount Matt Helsley
2020-06-09 8:54 ` Julien Thierry
2020-06-09 15:42 ` Matt Helsley
2020-06-09 19:31 ` Julien Thierry
2020-06-02 19:49 ` [RFC][PATCH v4 02/32] objtool: Make recordmcount into mcount subcmd Matt Helsley
2020-06-09 9:00 ` Julien Thierry
2020-06-09 18:39 ` Matt Helsley
2020-06-09 18:52 ` Steven Rostedt
2020-06-09 18:56 ` Matt Helsley
2020-06-09 19:11 ` Julien Thierry
2020-06-02 19:49 ` [RFC][PATCH v4 03/32] objtool: recordmcount: Start using objtool's elf wrapper Matt Helsley
2020-06-02 19:49 ` [RFC][PATCH v4 04/32] objtool: recordmcount: Search for __mcount_loc before walking the sections Matt Helsley
2020-06-02 19:49 ` [RFC][PATCH v4 05/32] objtool: recordmcount: Convert do_func() relhdrs Matt Helsley
2020-06-02 19:49 ` [RFC][PATCH v4 06/32] objtool: mcount: Remove unused fname parameter Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 07/32] objtool: mcount: Use libelf for section header names Matt Helsley
2020-06-02 19:50 ` Matt Helsley [this message]
2020-06-02 19:50 ` [RFC][PATCH v4 09/32] objtool: mcount: Use symbol structs to find mcount relocations Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 10/32] objtool: mcount: Walk relocation lists Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 11/32] objtool: mcount: Move get_mcountsym Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 12/32] objtool: mcount: Replace MIPS offset types Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 13/32] objtool: mcount: Move is_fake_mcount() Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 14/32] objtool: mcount: Stop using ehdr in find_section_sym_index Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 15/32] objtool: mcount: Move find_section_sym_index() Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 16/32] objtool: mcount: Restrict using ehdr in append_func() Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 17/32] objtool: mcount: Use objtool ELF to write Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 18/32] objtool: mcount: Move nop_mcount() Matt Helsley
2020-06-12 13:26 ` Peter Zijlstra
2020-06-12 16:05 ` Peter Zijlstra
2020-06-17 17:36 ` Matt Helsley
2020-06-17 18:30 ` Peter Zijlstra
2020-06-13 19:49 ` Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 19/32] objtool: mcount: Move has_rel_mcount() and tot_relsize() Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 20/32] objtool: mcount: Move relocation entry size detection Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 21/32] objtool: mcount: Only keep ELF file size Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 22/32] objtool: mcount: Use ELF header from objtool Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 23/32] objtool: mcount: Remove unused file mapping Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 24/32] objtool: mcount: Reduce usage of _size wrapper Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 25/32] objtool: mcount: Move mcount_adjust out of wrapper Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 26/32] objtool: mcount: Pre-allocate new ELF sections Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 27/32] objtool: mcount: Generic location and relocation table types Matt Helsley
2020-06-09 6:41 ` Kamalesh Babulal
2020-06-09 18:12 ` Matt Helsley
2020-06-10 4:35 ` Kamalesh Babulal
2020-06-02 19:50 ` [RFC][PATCH v4 28/32] objtool: mcount: Move sift_rel_mcount out of wrapper file Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 29/32] objtool: mcount: Remove wrapper for ELF relocation type Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 30/32] objtool: mcount: Remove wrapper double-include trick Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 31/32] objtool: mcount: Remove endian wrappers Matt Helsley
2020-06-02 19:50 ` [RFC][PATCH v4 32/32] objtool: mcount: Rename Matt Helsley
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