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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 38/51] objtool: mcount: mcount symbol name simplification
Date: Thu, 18 Jun 2020 13:38:24 -0700	[thread overview]
Message-ID: <2aefb1817980e30ec3ff3803eb0236a87d17c26a.1592510545.git.mhelsley@vmware.com> (raw)
In-Reply-To: <cover.1592510545.git.mhelsley@vmware.com>

Remove gpfx -- the recognized prefix for the mcount symbol
-- and just recognize any of the prefixes. This allows us
to further substitute the various strings directly into the
code rather than using variables.

Signed-off-by: Matt Helsley <mhelsley@vmware.com>
---
 tools/objtool/mcount.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/tools/objtool/mcount.c b/tools/objtool/mcount.c
index 7e621769c488..4d6596a031bf 100644
--- a/tools/objtool/mcount.c
+++ b/tools/objtool/mcount.c
@@ -43,7 +43,6 @@
 
 #define R_ARM_THM_CALL		10
 
-static char gpfx;	/* prefix for global symbol name (sometimes '_') */
 extern int warn_on_notrace_sect; /* warn when section has mcount not being recorded */
 
 static struct elf *lf;
@@ -166,14 +165,16 @@ static struct symbol *get_mcount_sym(struct reloc *reloc)
 {
 	struct symbol *sym = reloc->sym;
 	char const *symname = sym->name;
-	char const *mcount = gpfx == '_' ? "_mcount" : "mcount";
-	char const *fentry = "__fentry__";
 
 	if (symname[0] == '.')
-		++symname;  /* ppc64 hack */
-	if (strcmp(mcount, symname) == 0 ||
+		symname++;  /* ppc64 hack */
+
+	if (symname[0] == '_')
+		symname++;
+
+	if (strcmp("mcount", symname) == 0 ||
 	    (strcmp("__gnu_mcount_nc", symname) == 0) ||
-	    (strcmp(fentry, symname) == 0))
+	    (strcmp("_fentry__", symname) == 0))
 		return sym;
 	return NULL;
 }
@@ -550,7 +551,6 @@ static int do_file(char const *const fname)
 		goto out;
 	}
 
-	gpfx = '_';
 	switch (lf->ehdr.e_machine) {
 	default:
 		fprintf(stderr, "unrecognized e_machine %u %s\n",
@@ -562,14 +562,12 @@ static int do_file(char const *const fname)
 		make_nop = make_nop_x86;
 		ideal_nop = ideal_nop5_x86_32;
 		mcount_adjust = -1;
-		gpfx = 0;
 		break;
 	case EM_ARM:
 		reltype = R_ARM_ABS32;
 		make_nop = make_nop_arm;
 		rel_type_nop = R_ARM_NONE;
 		is_fake_mcount = arm_is_fake_mcount;
-		gpfx = 0;
 		break;
 	case EM_AARCH64:
 		reltype = R_AARCH64_ABS64;
@@ -582,7 +580,7 @@ static int do_file(char const *const fname)
 	case EM_PPC:	reltype = R_PPC_ADDR32; break;
 	case EM_PPC64:	reltype = R_PPC64_ADDR64; break;
 	case EM_S390:	/* reltype: e_class    */ break;
-	case EM_SH:	reltype = R_SH_DIR32; gpfx = 0; break;
+	case EM_SH:	reltype = R_SH_DIR32;  break;
 	case EM_SPARCV9: reltype = R_SPARC_64; break;
 	case EM_X86_64:
 		make_nop = make_nop_x86;
@@ -590,7 +588,6 @@ static int do_file(char const *const fname)
 		reltype = R_X86_64_64;
 		rel_type_nop = R_X86_64_NONE;
 		mcount_adjust = -1;
-		gpfx = 0;
 		break;
 	}  /* end switch */
 
-- 
2.20.1


  parent reply	other threads:[~2020-06-18 20:42 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 ` Matt Helsley [this message]
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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