On Sun, 2010-10-24 at 02:53 +0800, wu zhangjin wrote:
> (Add John F. Reiser in this loop)
>
> On 10/23/10, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > On Fri, 2010-10-22 at 14:10 -0700, David Daney wrote:
> >> On 10/22/2010 01:58 PM, Wu Zhangjin wrote:
> >> > From: Wu Zhangjin<wuzhangjin@xxxxxxxxx>
> >> >
> >> > In some situations(with related kernel config and gcc options), the
> >> > modules may have the same address space as the core kernel space, so
> >> > mcount_regex for modules should also match R_MIPS_26.
> >> >
> >>
> >> I think Steve is rewriting this bit to be a pure C program. Is this
> >> file even used anymore? If so for how long?
> >
> > It's already in mainline, but is only supported for x86 for now. Until
> > we verify that it works for other archs (which is up to you guys to
> > verify) the script will still be used.
> >
> > Also, I did not write it, John Reiser did. I just cleaned it up a bit
> > and got it working with the build system.
>
> Just applied this tmp patch to try the basic function.
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index ce8af84..3bf1c0c 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -9,6 +9,7 @@ config MIPS
> select HAVE_FUNCTION_TRACE_MCOUNT_TEST
> select HAVE_DYNAMIC_FTRACE
> select HAVE_FTRACE_MCOUNT_RECORD
> + select HAVE_C_RECORDMCOUNT
> select HAVE_FUNCTION_GRAPH_TRACER
> select HAVE_KPROBES
> select HAVE_KRETPROBES
> diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
> index 26e1271..0fb200f 100644
> --- a/scripts/recordmcount.c
> +++ b/scripts/recordmcount.c
> @@ -270,6 +270,7 @@ do_file(char const *const fname)
> case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
> case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
> case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;
> + case EM_MIPS: reltype = R_MIPS_26; gpfx = '_'; break;
> case EM_S390: /* reltype: e_class */ gpfx = '_'; break;
> case EM_SH: reltype = R_SH_DIR32; break;
> case EM_SPARCV9: reltype = R_SPARC_64; gpfx = '_'; break;
>
> (Note: The above patch is not enough, for the modules with
> -mlong-calls, the reltype should be R_MIPS_HI16, and we may also need
> to add our specific code for sift_rel_mcount() to get the right
> location of the _mcount calling site)
>
> but failed with the following error:
>
> $ make ARCH=mips CROSS_COMPILE=mips64el-unknown-linux-gnu-
> CHK include/linux/version.h
> CHK include/generated/utsrelease.h
> HOSTCC scripts/basic/fixdep
> HOSTCC scripts/basic/docproc
> scripts/basic/docproc.c: In function âdocsectâ:
> scripts/basic/docproc.c:336: warning: ignoring return value of
> âasprintfâ, declared with attribute warn_unused_result
> Checking missing-syscalls for N32
> CALL scripts/checksyscalls.sh
> Checking missing-syscalls for O32
> CALL scripts/checksyscalls.sh
> CC kernel/bounds.s
> GEN include/generated/bounds.h
> CC arch/mips/kernel/asm-offsets.s
> GEN include/generated/asm-offsets.h
> CALL scripts/checksyscalls.sh
> CC scripts/mod/empty.o
> HOSTCC scripts/mod/mk_elfconfig
> MKELF scripts/mod/elfconfig.h
> HOSTCC scripts/mod/file2alias.o
> HOSTCC scripts/mod/modpost.o
> HOSTCC scripts/mod/sumversion.o
> HOSTLD scripts/mod/modpost
> HOSTCC scripts/kallsyms
> HOSTCC scripts/conmakehash
> HOSTCC scripts/bin2c
> HOSTCC scripts/recordmcount
> CC init/main.o
> /bin/sh: line 1: 21835 Segmentation fault scripts/recordmcount "init/main.o"
> make[1]: *** [init/main.o] Error 139
> make: *** [init] Error 2
>
> I traced the problem and found it was triggered by the 201 line of
> scripts/recordmcount.h:
>
> 198 if (!mcountsym) {
> 199 Elf_Sym const *const symp =
> 200 &sym0[ELF_R_SYM(_w(relp->r_info))];
> *201 char const *symname = &str0[w(symp->st_name)];*
I merged the 32bit and 64bit here. It may be my fault on this one ;-)
I'll look into it on Monday. Thanks,
-- Steve
> 202
> 203 if ('.' == symname[0])
> 204 ++symname; /* ppc64 hack */
>
> Exactly, it was triggered by: symp->st_name, symp is normal address,
> i.e. 0xa01831f0, but perhaps the content pointed by this address may
> not exist or is not allocated before?
>
> Did I miss something for MIPS specific support?
>
> By the way, because MIPS need to cope with its modules
> particularly(differ from the module):
>
> for kernel:
>
> # 10: 03e0082d move at,ra
> # 14: 0c000000 jal 0
> # 14: R_MIPS_26 _mcount --> we
> record this for MIPS kernel
> # 14: R_MIPS_NONE *ABS*
> # 14: R_MIPS_NONE *ABS*
> # 18: 00020021 nop
>
>
> for module:
>
> # c: 3c030000 lui v1,0x0
> # c: R_MIPS_HI16 _mcount --> we record
> this for MIPS module
> # 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:
>
> But I found there was only one argument: /path/to/file.o passed to
> scripts/recordmount:
>
> scripts/Makefile.build
>
> 217 cmd_record_mcount = if [ $(@) != "scripts/mod/empty.o" ]; then
> \
> 218 $(objtree)/scripts/recordmcount "$(@)";
> \
> 219 fi;
> 220 else
>
> So, should we pass "$(if $(part-of-module),1,0)" to the C version of
> recordmcount?
>
> Regards,
> Wu Zhangjin
