Re: [patch v4 10/13] gdbserver, linux, btrace: add btrace support for linux-low

Pedro Alves
2012-11-28T20:44:26Z

On 11/27/2012 10:49 AM, markus.t.metzger@intel.com wrote:
> From: Markus Metzger <markus.t.metzger@intel.com>
>
> Implement btrace target ops in target linux-low using the common linux-btrace
> functions.
>
> Add linux-btrace.o to all targets that link linux-low.o. I'd rather not link it
> to targets that do not support branch tracing, but this would require changing
> the way target ops are defined for gdbserver.

A simple way to do this would be to have configure.src set srv_linux_btrace=yes
and then configure.ac would do:

if test "${srv_linux_btrace}" = "yes"; then
AC_DEFINE(HAVE_BTRACE, 1,
[Define if the target supports branch tracing])
fi

You'd then do e.g.,:

@@ -5858,6 +5884,11 @@ static struct target_ops linux_target_ops = {
linux_get_min_fast_tracepoint_insn_len,
linux_qxfer_libraries_svr4,
linux_supports_agent,
+ #if HAVE_BTRACE
+ linux_supports_btrace,
+ linux_enable_btrace,
+ linux_disable_btrace,
+ linux_btrace_has_changed,
+ linux_low_read_btrace,
+ #endif
};

>
> 2012-11-27 Markus Metzger <markus.t.metzger@intel.com>
>
> gdbserver/
> * linux-low: Include linux-btrace.h.
> (linux_low_enable_btrace): New function.
> (linux_low_read_btrace): New function.
> (linux_target_ops): Add btrace ops.
> * configure.srv: Add linux-btrace.o.
>
>
> ---
> gdb/gdbserver/configure.srv | 34 +++++++++++++++++-----------------
> gdb/gdbserver/linux-low.c | 31 +++++++++++++++++++++++++++++++
> 2 files changed, 48 insertions(+), 17 deletions(-)
>
> diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv
> index d1e04a9..ae247b8 100644
> --- a/gdb/gdbserver/configure.srv
> +++ b/gdb/gdbserver/configure.srv
> @@ -47,7 +47,7 @@ case "${target}" in
> srv_regobj="${srv_regobj} arm-with-vfpv3.o"
> srv_regobj="${srv_regobj} arm-with-neon.o"
> srv_tgtobj="linux-low.o linux-osdata.o linux-arm-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_xmlfiles="arm-with-iwmmxt.xml"
> srv_xmlfiles="${srv_xmlfiles} arm-with-vfpv2.xml"
> srv_xmlfiles="${srv_xmlfiles} arm-with-vfpv3.xml"
> @@ -70,19 +70,19 @@ case "${target}" in
> ;;
> bfin-*-*linux*) srv_regobj=reg-bfin.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-bfin-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_thread_db=yes
> ;;
> crisv32-*-linux*) srv_regobj=reg-crisv32.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-crisv32-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> ;;
> cris-*-linux*) srv_regobj=reg-cris.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-cris-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_thread_db=yes
> ;;
> @@ -97,7 +97,7 @@ case "${target}" in
> srv_xmlfiles="${srv_xmlfiles} $srv_amd64_linux_xmlfiles"
> fi
> srv_tgtobj="linux-low.o linux-osdata.o linux-x86-low.o i386-low.o i387-fp.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> @@ -129,12 +129,12 @@ case "${target}" in
> ;;
> ia64-*-linux*) srv_regobj=reg-ia64.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-ia64-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> ;;
> m32r*-*-linux*) srv_regobj=reg-m32r.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-m32r-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_thread_db=yes
> ;;
> @@ -144,7 +144,7 @@ case "${target}" in
> srv_regobj=reg-m68k.o
> fi
> srv_tgtobj="linux-low.o linux-osdata.o linux-m68k-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> @@ -155,7 +155,7 @@ case "${target}" in
> srv_regobj=reg-m68k.o
> fi
> srv_tgtobj="linux-low.o linux-osdata.o linux-m68k-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> @@ -165,7 +165,7 @@ case "${target}" in
> srv_regobj="${srv_regobj} mips64-linux.o"
> srv_regobj="${srv_regobj} mips64-dsp-linux.o"
> srv_tgtobj="linux-low.o linux-osdata.o linux-mips-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_xmlfiles="mips-linux.xml"
> srv_xmlfiles="${srv_xmlfiles} mips-dsp-linux.xml"
> srv_xmlfiles="${srv_xmlfiles} mips-cpu.xml"
> @@ -198,7 +198,7 @@ case "${target}" in
> srv_regobj="${srv_regobj} powerpc-isa205-altivec64l.o"
> srv_regobj="${srv_regobj} powerpc-isa205-vsx64l.o"
> srv_tgtobj="linux-low.o linux-osdata.o linux-ppc-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_xmlfiles="rs6000/powerpc-32l.xml"
> srv_xmlfiles="${srv_xmlfiles} rs6000/powerpc-altivec32l.xml"
> srv_xmlfiles="${srv_xmlfiles} rs6000/powerpc-cell32l.xml"
> @@ -241,7 +241,7 @@ case "${target}" in
> srv_regobj="${srv_regobj} s390x-linux64v1.o"
> srv_regobj="${srv_regobj} s390x-linux64v2.o"
> srv_tgtobj="linux-low.o linux-osdata.o linux-s390-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_xmlfiles="s390-linux32.xml"
> srv_xmlfiles="${srv_xmlfiles} s390-linux32v1.xml"
> srv_xmlfiles="${srv_xmlfiles} s390-linux32v2.xml"
> @@ -262,14 +262,14 @@ case "${target}" in
> ;;
> sh*-*-linux*) srv_regobj=reg-sh.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-sh-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_usrregs=yes
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> ;;
> sparc*-*-linux*) srv_regobj=reg-sparc64.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-sparc-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_regsets=yes
> srv_linux_thread_db=yes
> ;;
> @@ -286,14 +286,14 @@ case "${target}" in
> srv_xmlfiles="${srv_xmlfiles} tic6x-gp.xml"
> srv_xmlfiles="${srv_xmlfiles} tic6x-c6xp.xml"
> srv_tgtobj="linux-low.o linux-osdata.o linux-tic6x-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_regsets=yes
> srv_linux_usrregs=yes
> srv_linux_thread_db=yes
> ;;
> x86_64-*-linux*) srv_regobj="$srv_amd64_linux_regobj $srv_i386_linux_regobj"
> srv_tgtobj="linux-low.o linux-osdata.o linux-x86-low.o i386-low.o i387-fp.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_xmlfiles="$srv_i386_linux_xmlfiles $srv_amd64_linux_xmlfiles"
> srv_linux_usrregs=yes # This is for i386 progs.
> srv_linux_regsets=yes
> @@ -308,7 +308,7 @@ case "${target}" in
>
> xtensa*-*-linux*) srv_regobj=reg-xtensa.o
> srv_tgtobj="linux-low.o linux-osdata.o linux-xtensa-low.o linux-procfs.o"
> - srv_tgtobj="${srv_tgtobj} linux-ptrace.o"
> + srv_tgtobj="${srv_tgtobj} linux-ptrace.o linux-btrace.o"
> srv_linux_regsets=yes
> ;;
> tilegx-*-linux*) srv_regobj=reg-tilegx.o
> diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
> index c697f6b..ffaa96f 100644
> --- a/gdb/gdbserver/linux-low.c
> +++ b/gdb/gdbserver/linux-low.c
> @@ -20,6 +20,7 @@
> #include "linux-low.h"
> #include "linux-osdata.h"
> #include "agent.h"
> +#include "linux-btrace.h"
>
> #include "gdb_wait.h"
> #include <stdio.h>
> @@ -5794,6 +5795,31 @@ linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf,
> return len;
> }
>
> +/* Read branch trace data for @tinfo as btrace xml document into @buffer. */
> +static void
> +linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer)
> +{
> + VEC (btrace_block_s) *btrace;
> + struct btrace_block *block;
> + int i;
> +
> + if (!tinfo->ptr_bits)
> + tinfo->ptr_bits = register_size (0) * 8;

Same comment as in the gdb patch.

> +
> + btrace = linux_read_btrace (tinfo);
> +
> + buffer_grow_str (buffer, " \n");
> + buffer_grow_str (buffer, "<btrace version=\"1.0\">\n");
> +
> + for (i = 0; VEC_iterate (btrace_block_s, btrace, i, block); i++)
> + buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
> + paddress (block->begin), paddress (block->end));
> +
> + buffer_grow_str (buffer, "</btrace>\n");
> +
> + VEC_free (btrace_block_s, btrace);
> +}
> +
> static struct target_ops linux_target_ops = {
> linux_create_inferior,
> linux_attach,
> @@ -5858,6 +5884,11 @@ static struct target_ops linux_target_ops = {
> linux_get_min_fast_tracepoint_insn_len,
> linux_qxfer_libraries_svr4,
> linux_supports_agent,
> + linux_supports_btrace,
> + linux_enable_btrace,
> + linux_disable_btrace,
> + linux_btrace_has_changed,
> + linux_low_read_btrace,
> };
>
> static void
>

--
Pedro Alves