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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>,
	Julien Thierry <jthierry@redhat.com>,
	Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
	Matt Helsley <mhelsley@vmware.com>
Subject: [RFC][PATCH v5 49/51] objtool: mcount: Remove relocation size check
Date: Thu, 18 Jun 2020 13:38:35 -0700	[thread overview]
Message-ID: <6daddf400359443d5b8a2d765794524d896e3d55.1592510545.git.mhelsley@vmware.com> (raw)
In-Reply-To: <cover.1592510545.git.mhelsley@vmware.com>

Rather than use the size of the relocations check the section
header type directly to see if the mcount relocations should
be rel or rela relocations.

Signed-off-by: Matt Helsley <mhelsley@vmware.com>
---
 tools/objtool/elf.c    |  4 ++--
 tools/objtool/elf.h    |  2 +-
 tools/objtool/mcount.c | 15 +++++----------
 3 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 733e10d4a574..4948df31bba0 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -642,8 +642,8 @@ static int read_relocs(struct elf *elf)
 
 		sec->base->reloc = sec;
 		sec->mcountable = relocs_mcountable(sec);
-		if (sec->mcountable && !elf->mcount_rel_entsize)
-			elf->mcount_rel_entsize = sec->sh.sh_entsize;
+		if (sec->mcountable)
+			elf->mcount_r_addends = (sec->sh.sh_type == SHT_RELA);
 
 		nr_reloc = 0;
 		for (i = 0; i < sec->sh.sh_size / sec->sh.sh_entsize; i++) {
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 8ece1ca79cca..f298e327af01 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -87,8 +87,8 @@ struct elf {
 	Elf *elf;
 	GElf_Ehdr ehdr;
 	int fd;
-	size_t mcount_rel_entsize;
 	bool changed;
+	bool mcount_r_addends;
 	char *name;
 	struct list_head sections;
 	DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
diff --git a/tools/objtool/mcount.c b/tools/objtool/mcount.c
index 9527924af56b..084bbc02de0c 100644
--- a/tools/objtool/mcount.c
+++ b/tools/objtool/mcount.c
@@ -368,22 +368,17 @@ static void fill_mcount_locs(GElf_Sxword r_offset, GElf_Addr **rbuf,
 }
 
 /* Overall supervision for Elf32 ET_REL file. */
-static int do_mcount(unsigned const reltype, size_t rela_size)
+static int do_mcount(unsigned const reltype)
 {
-	GElf_Sxword r_offset = 0;
-
 	struct section *sec, *mlocs, *mrels;
 	const char * const mc_name =  "__mcount_loc";
-
-	const unsigned int rel_entsize = lf->mcount_rel_entsize;
+	GElf_Sxword r_offset = 0;
 	int result = -1;
-	bool is_rela;
+	const bool is_rela = lf->mcount_r_addends;
 
 	if (find_section_by_name(lf, "__mcount_loc") != NULL)
 		return 0;
 
-	is_rela = (rela_size == rel_entsize);
-
 	/* add section: __mcount_loc */
 	mlocs = elf_create_section(lf, mc_name, sizeof(GElf_Addr), 0);
 	if (!mlocs)
@@ -562,7 +557,7 @@ static int do_file(char const *const fname)
 			is_fake_mcount = MIPS_is_fake_mcount;
 		}
 		loc_size = 4;
-		rc = do_mcount(reltype, sizeof(Elf32_Rela));
+		rc = do_mcount(reltype);
 		break;
 	case ELFCLASS64: {
 		if (lf->ehdr.e_ehsize != sizeof(Elf64_Ehdr)
@@ -580,7 +575,7 @@ static int do_file(char const *const fname)
 			is_fake_mcount = MIPS_is_fake_mcount;
 		}
 		loc_size = 8;
-		rc = do_mcount(reltype, sizeof(Elf64_Rela));
+		rc = do_mcount(reltype);
 		break;
 	}
 	}  /* end switch */
-- 
2.20.1


  parent reply	other threads:[~2020-06-18 20:41 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-18 20:37 [RFC][PATCH v5 00/51] objtool: Make recordmcount a subcommand Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 01/51] objtool: Factor out reasons to build objtool Matt Helsley
2020-06-24 15:37   ` Miroslav Benes
2020-06-18 20:37 ` [RFC][PATCH v5 02/51] objtool: Prepare to merge recordmcount Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 03/51] objtool: Make recordmcount into mcount subcmd Matt Helsley
2020-06-25 10:39   ` Miroslav Benes
2020-06-18 20:37 ` [RFC][PATCH v5 04/51] objtool: recordmcount: Start using objtool's elf wrapper Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 05/51] objtool: recordmcount: Search for __mcount_loc before walking the sections Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 06/51] objtool: recordmcount: Convert do_func() relhdrs Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 07/51] objtool: mcount: Move nhdr into find_symtab() Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 08/51] objtool: mcount: Remove unused fname parameter Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 09/51] objtool: mcount: Use libelf for section header names Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 10/51] objtool: mcount: Walk objtool Elf structs in find_secsym_ndx Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 11/51] objtool: mcount: Use symbol structs to find mcount relocations Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 12/51] objtool: mcount: Walk relocation lists Matt Helsley
2020-06-18 20:37 ` [RFC][PATCH v5 13/51] objtool: mcount: Return symbol from mcountsym Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 14/51] objtool: mcount: Move get_mcountsym Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 15/51] objtool: mcount: Replace MIPS offset types Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 16/51] objtool: mcount: Move is_fake_mcount() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 17/51] objtool: mcount: Stop using ehdr in find_section_sym_index Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 18/51] objtool: mcount: Move find_section_sym_index() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 19/51] objtool: mcount: Restrict using ehdr in append_func() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 20/51] objtool: mcount: Use objtool ELF to write Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 21/51] objtool: mcount: Move nop_mcount() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 22/51] objtool: mcount: Move has_rel_mcount() and tot_relsize() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 23/51] objtool: mcount: Move relocation entry size detection Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 24/51] objtool: mcount: Only keep ELF file size Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 25/51] objtool: mcount: Use ELF header from objtool Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 26/51] objtool: mcount: Remove unused file mapping Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 27/51] objtool: mcount: Reduce usage of _size wrapper Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 28/51] objtool: mcount: Move mcount_adjust out of wrapper Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 29/51] objtool: mcount: Pre-allocate new ELF sections Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 30/51] objtool: mcount: Generic location and relocation table types Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 31/51] objtool: mcount: Use objtool relocation section Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 32/51] objtool: mcount: Move sift_rel_mcount out of wrapper file Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 33/51] objtool: mcount: Remove wrapper for ELF relocation type Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 34/51] objtool: mcount: Remove wrapper double-include trick Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 35/51] objtool: mcount: Remove endian wrappers Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 36/51] objtool: mcount: Rename to mcount.c Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 37/51] objtool: mcount: Simplify mcount name matching Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 38/51] objtool: mcount: mcount symbol name simplification Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 39/51] objtool: mcount: Verify x86 instruction with memcmp() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 40/51] objtool: mcount: const-ify ARM instruction patterns Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 41/51] objtool: mcount: Convert nop writes to elf_write_insn() Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 42/51] objtool: mcount: Move mcount symbol name testing Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 43/51] objtool: check: Use class to recognize kcov calls Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 44/51] objtool: mcount: Keep lists locations and relocations Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 45/51] objtool: mcount: Move mcount section test to objtool ELF Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 46/51] objtool: mcount: Flag mcount relocation sections Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 47/51] objtool: mcount: Merge section mcount flags Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 48/51] objtool: mcount: Eliminate first pass Matt Helsley
2020-06-18 20:38 ` Matt Helsley [this message]
2020-06-18 20:38 ` [RFC][PATCH v5 50/51] objtool: mcount: Remove useless lookup Matt Helsley
2020-06-18 20:38 ` [RFC][PATCH v5 51/51] objtool: mcount: Remove stale description Matt Helsley
2020-06-23 14:12 ` [RFC][PATCH v5 00/51] objtool: Make recordmcount a subcommand Matt Helsley

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