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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 18/51] objtool: mcount: Move find_section_sym_index()
Date: Thu, 18 Jun 2020 13:38:04 -0700	[thread overview]
Message-ID: <68b37fd2066c8c6709fcd4246162d856f84a5943.1592510545.git.mhelsley@vmware.com> (raw)
In-Reply-To: <cover.1592510545.git.mhelsley@vmware.com>

This function is no longer dependent upon the old recordmcount
ELF wrapper code -- it doesn't use the wrapper's Elf_* types nor
does it call wrapped functions. Move it into the C file.

Signed-off-by: Matt Helsley <mhelsley@vmware.com>
---
 tools/objtool/recordmcount.c | 42 ++++++++++++++++++++++++++++++++
 tools/objtool/recordmcount.h | 47 +-----------------------------------
 2 files changed, 43 insertions(+), 46 deletions(-)

diff --git a/tools/objtool/recordmcount.c b/tools/objtool/recordmcount.c
index 24b019b82795..2225479157e5 100644
--- a/tools/objtool/recordmcount.c
+++ b/tools/objtool/recordmcount.c
@@ -482,6 +482,48 @@ static int (*is_fake_mcount)(struct reloc const *reloc) = fn_is_fake_mcount;
 
 static const unsigned int missing_sym = (unsigned int)-1;
 
+/*
+ * Find a symbol in the given section, to be used as the base for relocating
+ * the table of offsets of calls to mcount.  A local or global symbol suffices,
+ * but avoid a Weak symbol because it may be overridden; the change in value
+ * would invalidate the relocations of the offsets of the calls to mcount.
+ * Often the found symbol will be the unnamed local symbol generated by
+ * GNU 'as' for the start of each section.  For example:
+ *    Num:    Value  Size Type    Bind   Vis      Ndx Name
+ *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
+ */
+static int find_section_sym_index(unsigned const txtndx,
+				char const *const txtname,
+				unsigned long *const recvalp,
+				unsigned int *sym_index)
+{
+	struct symbol *sym;
+	struct section *txts = find_section_by_index(lf, txtndx);
+
+	if (!txts) {
+		fprintf(stderr, "Cannot find section %u: %s.\n",
+			txtndx, txtname);
+		return missing_sym;
+	}
+
+	list_for_each_entry(sym, &txts->symbol_list, list) {
+		/* avoid symbols with weak binding */
+		if ((sym->bind == STB_LOCAL) || (sym->bind == STB_GLOBAL)) {
+			/* function symbols on ARM have quirks, avoid them */
+			if (lf->ehdr.e_machine == EM_ARM
+			    && sym->type == STT_FUNC)
+				continue;
+
+			*recvalp = sym->sym.st_value;
+			*sym_index = sym->idx;
+			return 0;
+		}
+	}
+	fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
+		txtndx, txtname);
+	return missing_sym;
+}
+
 /* 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 cf420f9f64b0..eed592954f37 100644
--- a/tools/objtool/recordmcount.h
+++ b/tools/objtool/recordmcount.h
@@ -21,7 +21,6 @@
 #undef mcount_adjust
 #undef sift_rel_mcount
 #undef nop_mcount
-#undef find_section_sym_index
 #undef has_rel_mcount
 #undef tot_relsize
 #undef get_shnum
@@ -44,7 +43,6 @@
 # define append_func		append64
 # define sift_rel_mcount	sift64_rel_mcount
 # define nop_mcount		nop_mcount_64
-# define find_section_sym_index	find64_section_sym_index
 # define has_rel_mcount		has64_rel_mcount
 # define tot_relsize		tot64_relsize
 # define get_shnum		get_shnum64
@@ -67,7 +65,6 @@
 # define append_func		append32
 # define sift_rel_mcount	sift32_rel_mcount
 # define nop_mcount		nop_mcount_32
-# define find_section_sym_index	find32_section_sym_index
 # define has_rel_mcount		has32_rel_mcount
 # define tot_relsize		tot32_relsize
 # define get_shnum		get_shnum32
@@ -307,48 +304,6 @@ static int nop_mcount(struct section * const rels,
 	return 0;
 }
 
-/*
- * Find a symbol in the given section, to be used as the base for relocating
- * the table of offsets of calls to mcount.  A local or global symbol suffices,
- * but avoid a Weak symbol because it may be overridden; the change in value
- * would invalidate the relocations of the offsets of the calls to mcount.
- * Often the found symbol will be the unnamed local symbol generated by
- * GNU 'as' for the start of each section.  For example:
- *    Num:    Value  Size Type    Bind   Vis      Ndx Name
- *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
- */
-static int find_section_sym_index(unsigned const txtndx,
-				char const *const txtname,
-				unsigned long *const recvalp,
-				unsigned int *sym_index)
-{
-	struct symbol *sym;
-	struct section *txts = find_section_by_index(lf, txtndx);
-
-	if (!txts) {
-		fprintf(stderr, "Cannot find section %u: %s.\n",
-			txtndx, txtname);
-		return missing_sym;
-	}
-
-	list_for_each_entry(sym, &txts->symbol_list, list) {
-		/* avoid symbols with weak binding */
-		if ((sym->bind == STB_LOCAL) || (sym->bind == STB_GLOBAL)) {
-			/* function symbols on ARM have quirks, avoid them */
-			if (lf->ehdr.e_machine == EM_ARM
-			    && sym->type == STT_FUNC)
-				continue;
-
-			*recvalp = sym->sym.st_value;
-			*sym_index = sym->idx;
-			return 0;
-		}
-	}
-	fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
-		txtndx, txtname);
-	return missing_sym;
-}
-
 static char const *has_rel_mcount(const struct section * const rels)
 {
 	const struct section *txts;
@@ -435,7 +390,7 @@ static int do_func(Elf_Ehdr *const ehdr,
 			rel_entsize = sec->sh.sh_entsize;
 			mlocp = sift_rel_mcount(mlocp,
 				(void *)mlocp - (void *)mloc0, &mrelp,
-				sec, recsym, recval, reltype);
+				sec, recsym, (uint_t)recval, reltype);
 		} else if (txtname && (warn_on_notrace_sect || make_nop)) {
 			/*
 			 * This section is ignored by ftrace, but still
-- 
2.20.1


  parent reply	other threads:[~2020-06-18 20:39 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 ` Matt Helsley [this message]
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 ` [RFC][PATCH v5 49/51] objtool: mcount: Remove relocation size check Matt Helsley
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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