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Message-ID: <cafad8d9aedc9f37a666cf58c043377a94ec90ed.1592510545.git.mhelsley@vmware.com>
Date: Thu, 18 Jun 2020 13:38:02 -0700
From: Matt Helsley <mhelsley@...are.com>
To: <linux-kernel@...r.kernel.org>
CC: Josh Poimboeuf <jpoimboe@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Steven Rostedt <rostedt@...dmis.org>,
Julien Thierry <jthierry@...hat.com>,
Kamalesh Babulal <kamalesh@...ux.vnet.ibm.com>,
Matt Helsley <mhelsley@...are.com>
Subject: [RFC][PATCH v5 16/51] objtool: mcount: Move is_fake_mcount()
Promote the now-bit-independent is_fake_mcount() out of the old
recordmcount ELF wrapper.
Signed-off-by: Matt Helsley <mhelsley@...are.com>
---
tools/objtool/recordmcount.c | 48 +++++++++++++++++++++++++++++++---
tools/objtool/recordmcount.h | 50 ------------------------------------
2 files changed, 45 insertions(+), 53 deletions(-)
diff --git a/tools/objtool/recordmcount.c b/tools/objtool/recordmcount.c
index d5f7c06afd57..24b019b82795 100644
--- a/tools/objtool/recordmcount.c
+++ b/tools/objtool/recordmcount.c
@@ -438,6 +438,48 @@ static struct symbol *get_mcountsym(struct reloc *reloc)
return NULL;
}
+/*
+ * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
+ * _mcount symbol is needed for dynamic function tracer, with it, to disable
+ * tracing(ftrace_make_nop), the instruction in the position is replaced with
+ * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
+ * instruction back. So, here, we set the 2nd one as fake and filter it.
+ *
+ * c: 3c030000 lui v1,0x0 <--> b label
+ * c: R_MIPS_HI16 _mcount
+ * c: R_MIPS_NONE *ABS*
+ * c: R_MIPS_NONE *ABS*
+ * 10: 64630000 daddiu v1,v1,0
+ * 10: R_MIPS_LO16 _mcount
+ * 10: R_MIPS_NONE *ABS*
+ * 10: R_MIPS_NONE *ABS*
+ * 14: 03e0082d move at,ra
+ * 18: 0060f809 jalr v1
+ * label:
+ */
+#define MIPS_FAKEMCOUNT_OFFSET 4
+
+static int MIPS_is_fake_mcount(struct reloc const *reloc)
+{
+ static unsigned long old_r_offset = ~0UL;
+ unsigned long current_r_offset = reloc->offset;
+ int is_fake;
+
+ is_fake = (old_r_offset != ~0UL) &&
+ (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
+ old_r_offset = current_r_offset;
+
+ return is_fake;
+}
+
+/* Functions and pointers that do_file() may override for specific e_machine. */
+static int fn_is_fake_mcount(struct reloc const *reloc)
+{
+ return 0;
+}
+
+static int (*is_fake_mcount)(struct reloc const *reloc) = fn_is_fake_mcount;
+
static const unsigned int missing_sym = (unsigned int)-1;
/* 32 bit and 64 bit are very similar */
@@ -557,7 +599,7 @@ static int do_file(char const *const fname)
altmcount = "__gnu_mcount_nc";
make_nop = make_nop_arm;
rel_type_nop = R_ARM_NONE;
- is_fake_mcount32 = arm_is_fake_mcount;
+ is_fake_mcount = arm_is_fake_mcount;
gpfx = 0;
break;
case EM_AARCH64:
@@ -597,7 +639,7 @@ static int do_file(char const *const fname)
}
if (w2(ehdr->e_machine) == EM_MIPS) {
reltype = R_MIPS_32;
- is_fake_mcount32 = MIPS32_is_fake_mcount;
+ is_fake_mcount = MIPS_is_fake_mcount;
}
if (do32(ehdr, reltype) < 0)
goto out;
@@ -617,7 +659,7 @@ static int do_file(char const *const fname)
if (w2(ghdr->e_machine) == EM_MIPS) {
reltype = R_MIPS_64;
Elf64_r_info = MIPS64_r_info;
- is_fake_mcount64 = MIPS64_is_fake_mcount;
+ is_fake_mcount = MIPS_is_fake_mcount;
}
if (do64(ghdr, reltype) < 0)
goto out;
diff --git a/tools/objtool/recordmcount.h b/tools/objtool/recordmcount.h
index dde2ec054e51..941f96e4f74b 100644
--- a/tools/objtool/recordmcount.h
+++ b/tools/objtool/recordmcount.h
@@ -18,9 +18,6 @@
* Copyright 2010 Steven Rostedt <srostedt@...hat.com>, Red Hat Inc.
*/
#undef append_func
-#undef is_fake_mcount
-#undef fn_is_fake_mcount
-#undef MIPS_is_fake_mcount
#undef mcount_adjust
#undef sift_rel_mcount
#undef nop_mcount
@@ -54,9 +51,6 @@
# define set_shnum set_shnum64
# define get_shstrndx get_shstrndx64
# define do_func do64
-# define is_fake_mcount is_fake_mcount64
-# define fn_is_fake_mcount fn_is_fake_mcount64
-# define MIPS_is_fake_mcount MIPS64_is_fake_mcount
# define mcount_adjust mcount_adjust_64
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Shdr Elf64_Shdr
@@ -80,9 +74,6 @@
# define set_shnum set_shnum32
# define get_shstrndx get_shstrndx32
# define do_func do32
-# define is_fake_mcount is_fake_mcount32
-# define fn_is_fake_mcount fn_is_fake_mcount32
-# define MIPS_is_fake_mcount MIPS32_is_fake_mcount
# define mcount_adjust mcount_adjust_32
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Shdr Elf32_Shdr
@@ -97,13 +88,6 @@
# define _size 4
#endif
-/* Functions and pointers that do_file() may override for specific e_machine. */
-static int fn_is_fake_mcount(struct reloc const *reloc)
-{
- return 0;
-}
-static int (*is_fake_mcount)(struct reloc const *reloc) = fn_is_fake_mcount;
-
static void fn_ELF_R_INFO(Elf_Rel *const rp, unsigned sym, unsigned type)
{
rp->r_info = _w(ELF_R_INFO(sym, type));
@@ -112,40 +96,6 @@ static void (*Elf_r_info)(Elf_Rel *const rp, unsigned sym, unsigned type) = fn_E
static int mcount_adjust = 0;
-/*
- * MIPS mcount long call has 2 _mcount symbols, only the position of the 1st
- * _mcount symbol is needed for dynamic function tracer, with it, to disable
- * tracing(ftrace_make_nop), the instruction in the position is replaced with
- * the "b label" instruction, to enable tracing(ftrace_make_call), replace the
- * instruction back. So, here, we set the 2nd one as fake and filter it.
- *
- * c: 3c030000 lui v1,0x0 <--> b label
- * c: R_MIPS_HI16 _mcount
- * c: R_MIPS_NONE *ABS*
- * c: R_MIPS_NONE *ABS*
- * 10: 64630000 daddiu v1,v1,0
- * 10: R_MIPS_LO16 _mcount
- * 10: R_MIPS_NONE *ABS*
- * 10: R_MIPS_NONE *ABS*
- * 14: 03e0082d move at,ra
- * 18: 0060f809 jalr v1
- * label:
- */
-#define MIPS_FAKEMCOUNT_OFFSET 4
-
-static int MIPS_is_fake_mcount(struct reloc const *reloc)
-{
- static unsigned long old_r_offset = ~0UL;
- unsigned long current_r_offset = reloc->offset;
- int is_fake;
-
- is_fake = (old_r_offset != ~0UL) &&
- (current_r_offset - old_r_offset == MIPS_FAKEMCOUNT_OFFSET);
- old_r_offset = current_r_offset;
-
- return is_fake;
-}
-
static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0)
{
if (shdr0 && !ehdr->e_shnum)
--
2.20.1
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