From: John Reiser <jreiser@bitwagon.com>
To: wu zhangjin <wuzhangjin@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
David Daney <ddaney@caviumnetworks.com>,
linux-mips@linux-mips.org, ralf@linux-mips.org
Subject: patch: [RFC 2/2] ftrace/MIPS: Add support for C version of recordmcount
Date: Sun, 24 Oct 2010 13:44:09 -0700 [thread overview]
Message-ID: <4CC49A99.1080601@bitwagon.com> (raw)
In-Reply-To: <AANLkTinwXjLAYACUfhLYaocHD_vBbiErLN3NjwN8JqSy@mail.gmail.com>
On 10/23/2010, wu zhangjin wrote:
> CC init/main.o
> /bin/sh: line 1: 21835 Segmentation fault scripts/recordmcount "init/main.o"
> make[1]: *** [init/main.o] Error 139
64-bit EM_MIPS has weird ELF64_Rela.info. Adjust recordmcount.[ch].
Signed-off-by: John Reiser <jreiser@BitWagon.com>
[I don't know where the git repository for recordmcount.h is,
so I have used a temporary one.]
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -212,11 +212,26 @@ is_mcounted_section_name(char const *const txtname)
0 == strcmp(".text.unlikely", txtname);
}
+
/* 32 bit and 64 bit are very similar */
#include "recordmcount.h"
#define RECORD_MCOUNT_64
#include "recordmcount.h"
+/* 64-bit EM_MIPS has weird ELF64_Rela.r_info */
+static uint64_t MIPS64_r_sym(Elf64_Xword xword)
+{
+ /* Perhaps this should be 40 bits, but kernel isn't that big. */
+ return 0xffffffff & xword;
+}
+
+static uint64_t MIPS64_r_info(Elf64_Xword sym, unsigned type)
+{
+ /* Type2 and Type3 are assumed zero. [See "readelf --relocs".] */
+ return (((uint64_t)type)<<56) | sym;
+}
+
+
static void
do_file(char const *const fname)
{
@@ -268,6 +283,7 @@ do_file(char const *const fname)
case EM_386: reltype = R_386_32; break;
case EM_ARM: reltype = R_ARM_ABS32; break;
case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
+ case EM_MIPS: /* reltype: e_class */ gpfx = '_'; break;
case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
@@ -291,6 +307,8 @@ do_file(char const *const fname)
}
if (EM_S390 == w2(ehdr->e_machine))
reltype = R_390_32;
+ if (EM_MIPS == w2(ehdr->e_machine))
+ reltype = R_MIPS_32;
do32(ehdr, fname, reltype);
} break;
case ELFCLASS64: {
@@ -303,6 +321,11 @@ do_file(char const *const fname)
}
if (EM_S390 == w2(ghdr->e_machine))
reltype = R_390_64;
+ if (EM_MIPS == w2(ghdr->e_machine)) {
+ reltype = R_MIPS_64;
+ Elf_r_sym = MIPS64_r_sym;
+ Elf_r_info = MIPS64_r_info;
+ }
do64(ghdr, fname, reltype);
} break;
} /* end switch */
--- a/scripts/recordmcount.h
+++ b/scripts/recordmcount.h
@@ -31,8 +31,12 @@
#undef Elf_Rela
#undef Elf_Sym
#undef ELF_R_SYM
+#undef Elf_r_sym
#undef ELF_R_INFO
+#undef Elf_r_info
#undef ELF_ST_BIND
+#undef fn_ELF_R_SYM
+#undef fn_ELF_R_INFO
#undef uint_t
#undef _w
#undef _align
@@ -52,8 +56,12 @@
# define Elf_Rela Elf64_Rela
# define Elf_Sym Elf64_Sym
# define ELF_R_SYM ELF64_R_SYM
+# define Elf_r_sym Elf64_r_sym
# define ELF_R_INFO ELF64_R_INFO
+# define Elf_r_info Elf64_r_info
# define ELF_ST_BIND ELF64_ST_BIND
+# define fn_ELF_R_SYM fn_ELF64_R_SYM
+# define fn_ELF_R_INFO fn_ELF64_R_INFO
# define uint_t uint64_t
# define _w w8
# define _align 7u
@@ -72,14 +80,32 @@
# define Elf_Rela Elf32_Rela
# define Elf_Sym Elf32_Sym
# define ELF_R_SYM ELF32_R_SYM
+# define Elf_r_sym Elf32_r_sym
# define ELF_R_INFO ELF32_R_INFO
+# define Elf_r_info Elf32_r_info
# define ELF_ST_BIND ELF32_ST_BIND
+# define fn_ELF_R_SYM fn_ELF32_R_SYM
+# define fn_ELF_R_INFO fn_ELF32_R_INFO
# define uint_t uint32_t
# define _w w
# define _align 3u
# define _size 4
#endif
+/* Functions and pointers that 64-bit EM_MIPS can override. */
+static uint_t fn_ELF_R_SYM(uint_t info)
+{
+ return ELF_R_SYM(info);
+}
+static uint_t (*Elf_r_sym)(uint_t info) = fn_ELF_R_SYM;
+
+static uint_t fn_ELF_R_INFO(uint_t sym, unsigned type)
+{
+ return ELF_R_INFO(sym, type);
+}
+static uint_t (*Elf_r_info)(uint_t sym, unsigned type) = fn_ELF_R_INFO;
+
+
/* Append the new shstrtab, Elf_Shdr[], __mcount_loc and its relocations. */
static void append_func(Elf_Ehdr *const ehdr,
Elf_Shdr *const shstr,
@@ -197,22 +223,22 @@ static uint_t *sift_rel_mcount(uint_t *mlocp,
for (t = nrel; t; --t) {
if (!mcountsym) {
Elf_Sym const *const symp =
- &sym0[ELF_R_SYM(_w(relp->r_info))];
+ &sym0[Elf_r_sym(_w(relp->r_info))];
char const *symname = &str0[w(symp->st_name)];
if ('.' == symname[0])
++symname; /* ppc64 hack */
if (0 == strcmp((('_' == gpfx) ? "_mcount" : "mcount"),
symname))
- mcountsym = ELF_R_SYM(_w(relp->r_info));
+ mcountsym = Elf_r_sym(_w(relp->r_info));
}
- if (mcountsym == ELF_R_SYM(_w(relp->r_info))) {
+ if (mcountsym == Elf_r_sym(_w(relp->r_info))) {
uint_t const addend = _w(_w(relp->r_offset) - recval);
mrelp->r_offset = _w(offbase
+ ((void *)mlocp - (void *)mloc0));
- mrelp->r_info = _w(ELF_R_INFO(recsym, reltype));
+ mrelp->r_info = _w(Elf_r_info(recsym, reltype));
if (sizeof(Elf_Rela) == rel_entsize) {
((Elf_Rela *)mrelp)->r_addend = addend;
*mlocp++ = 0;
--
John Reiser, jreiser@BitWagon.com
next prev parent reply other threads:[~2010-10-24 20:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-23 18:53 [RFC 2/2] ftrace/MIPS: Add support for C version of recordmcount wu zhangjin
2010-10-24 8:58 ` Steven Rostedt
2010-10-24 14:25 ` John Reiser
2010-10-24 20:44 ` John Reiser [this message]
2010-10-25 3:59 ` patch: " Maciej W. Rozycki
2010-10-25 12:28 ` John Reiser
2010-10-25 16:46 ` patch v2: " John Reiser
2010-10-25 18:17 ` wu zhangjin
2010-10-25 20:24 ` Steven Rostedt
2010-10-26 18:28 ` wu zhangjin
2010-10-26 13:36 ` Maciej W. Rozycki
2010-10-26 19:57 ` wu zhangjin
2010-10-27 9:31 ` Maciej W. Rozycki
2010-10-27 9:54 ` wu zhangjin
2010-10-26 21:21 ` wu zhangjin
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