old-cross-binutils/gdb/testsuite/lib/pdtrace.in
Jose E. Marchesi 497c491bea Simple testsuite for DTrace USDT probes.
This patch adds some simple tests testing the support for DTrace USDT
probes.  The testsuite will be skipped as unsupported in case the user
does not have DTrace installed on her system.  The tests included in the
test suite test breakpointing on DTrace probes, enabling and disabling
probes, printing of probe arguments of several types and also
breakpointing on several probes with the same name.

gdb/ChangeLog:

2015-02-17  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* lib/dtrace.exp: New file.
	* gdb.base/dtrace-probe.exp: Likewise.
	* gdb.base/dtrace-probe.d: Likewise.
	* gdb.base/dtrace-probe.c: Likewise.
	* lib/pdtrace.in: Likewise.
	* configure.ac: Output variables with the transformed names of
	the strip, readelf, as and nm tools.  AC_SUBST lib/pdtrace.in.
	* configure: Regenerated.
2015-02-17 16:41:16 +01:00

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#!/bin/sh
# A Poor(but Free)'s Man dtrace
#
# Copyright (C) 2014, 2015 Free Software Foundation, Inc.
#
# Contributed by Oracle, Inc.
#
# This file is part of GDB.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see
# <http://www.gnu.org/licenses/>.
# DISCLAIMER DISCLAIMER DISCLAIMER
# This script is a test tool. As such it is in no way intended to
# replace the "real" dtrace command for any practical purpose, apart
# from testing the DTrace USDT probes support in GDB.
# that said...
#
# pdtrace is a limited dtrace program, implementing a subset of its
# functionality:
#
# - The generation of an ELF file containing an embedded dtrace
# program. Equivalent to dtrace -G.
#
# - The generation of a header file with definitions for static
# probes. Equivalent to dtrace -h.
#
# This allows to generate DTrace static probes without having to use
# the user-level DTrace components. The generated objects are 100%
# compatible with DTrace and can be traced by the dtrace kernel module
# like if they were generated by dtrace.
#
# Some of the known limitations of this implementation are:
# - The input d-script must describe one provider, and only one.
# - The "probe " directives in the d-file must not include argument
# names, just the types. Thus something like `char *' is valid, but
# `char *name' is not.
# - The command line options must precede other arguments, since the
# script uses the (more) portable getopts.
# - Each probe header in the d-script must be contained in
# a single line.
# - strip -K removes the debugging information from the input object
# file.
# - The supported target platforms are i[3456]86 and x86_64.
#
# Please keep this code as portable as possible. Restrict yourself to
# POSIX sh.
# This script uses the following external programs, defined in
# variables. Some of them are substituted by autoconf.
TR=tr
NM=@NM_TRANSFORM_NAME@
EGREP=egrep
SED=sed
CUT=cut
READELF=@READELF_TRANSFORM_NAME@
SORT=sort
EXPR=expr
WC=wc
UNIQ=uniq
HEAD=head
SEQ=seq
AS=@GAS_TRANSFORM_NAME@
STRIP=@STRIP_TRANSFORM_NAME@
TRUE=true
# Sizes for several DOF structures, in bytes.
#
# See linux/dtrace/dof.h for the definition of the referred
# structures.
dof_hdrsize=64 # sizeof(dtrace_dof_hdr)
dof_secsize=32 # sizeof(dtrace_dof_sect)
dof_probesize=48 # sizeof(dtrace_dof_probe)
dof_providersize=44 # sizeof(dtrace_dof_provider)
# Types for the several DOF sections.
#
# See linux/dtrace/dof_defines.h for a complete list of section types
# along with their values.
dof_sect_type_strtab=8
dof_sect_type_provider=15
dof_sect_type_probes=16
dof_sect_type_prargs=17
dof_sect_type_proffs=18
dof_sect_type_prenoffs=26
### Functions
# Write a message to the standard error output and exit with an error
# status.
#
# Arguments:
# $1 error message.
f_panic()
{
echo "error: $1" 1>&2; exit 1
}
# Write a usage message to the standard output and exit with an error
# status.
f_usage()
{
printf "Usage: pdtrace [-32|-64] [-GhV] [-o output] [-s script] [ args ... ]\n\n"
printf "\t-32 generate 32-bit ELF files\n"
printf "\t-64 generate 64-bit ELF files\n\n"
printf "\t-G generate an ELF file containing embedded dtrace program\n"
printf "\t-h generate a header file with definitions for static probes\n"
printf "\t-o set output file\n"
printf "\t-s handle probes according to the specified D script\n"
printf "\t-V report the DTrace API version implemented by the tool\n"
exit 2
}
# Write a version message to the standard output and exit with a
# successful status.
f_version()
{
echo "pdtrace: Sun D 1.6.3"
exit
}
# Add a new record to a list and return it.
#
# Arguments:
# $1 is the list.
# $2 is the new record
f_add_record()
{
rec=$1
test -n "$rec" && \
{ rec=$(printf %s\\n "$rec"; echo x); rec=${rec%x}; }
printf %s "$rec$2"
}
# Collect the providers and probes information from the input object
# file.
#
# This function sets the values of the following global variables.
# The values are structured in records, each record in a line. The
# fields of each record are separated in some cases by white
# characters and in other cases by colon (:) characters.
#
# The type codes in the line format descriptors are:
# S: string, D: decimal number
#
# probes
# Regular probes and is-enabled probes.
# TYPE(S) PROVIDER(S) NAME(S) OFFSET(D) BASE(D) BASE_SYM(S)
# base_probes
# Base probes, i.e. probes sharing provider, name and container.
# PROVIDER(S) NAME(S) BASE(D) BASE_SYM(S)
# providers
# List of providers.
# PROVIDER(S)
# All the offsets are expressed in bytes.
#
# Input globals:
# objfile
# Output globals:
# probes, base_probes, providers
probes=
base_probes=
providers=
probes_args=
f_collect_probes()
{
# Probe points are function calls to undefined functions featuring
# distinct names for both normal probes and is-enabled probes.
PROBE_REGEX="(__dtrace_([a-zA-Z_]+)___([a-zA-Z_]+))"
EPROBE_REGEX="(__dtraceenabled_([a-zA-Z_]+)___([a-zA-Z_]+))"
while read type symbol provider name; do
test -z "$type" && f_panic "No probe points found in $objfile"
provider=$(printf %s $provider | $TR -s _)
name=$(printf %s $name | $TR -s _)
# Search the object file for relocations defined for the
# probe symbols. Then calculate the base address of the
# probe (along with the symbol associated with that base
# address) and the offset of the probe point.
for offset in $($READELF -W -r $objfile | $EGREP $symbol | $CUT -d' ' -f1)
do
# Figure out the base address for the probe. This is
# done finding the function name in the text section of
# the object file located above the probed point. But
# note that the relocation is for the address operand of
# the call instruction, so we have to subtract 1 to find
# the real probed point.
offset=$((0x$offset - 1))
# The addresses of is-enabled probes must point to the
# first NOP instruction in their patched instructions
# sequences, so modify them (see f_patch_objfile for the
# instruction sequences).
if test "$type" = "e"; then
if test "$objbits" -eq "32"; then
offset=$((offset + 2))
else # 64 bits
offset=$((offset + 3))
fi
fi
# Determine the base address of the probe and its
# corresponding function name.
funcs=$($NM -td $objfile | $EGREP "^[0-9]+ T " \
| $CUT -d' ' -f1,3 | $SORT -n -r | $TR ' ' :)
for fun in $funcs; do
func_off=$(printf %s $fun | $CUT -d: -f1)
func_sym=$(printf %s $fun | $CUT -d: -f2)
# Note that `expr' is used to remove leading zeros
# to avoid FUNC_OFF to be interpreted as an octal
# number in arithmetic contexts.
test "$func_off" -le "$offset" && \
{ base=$($EXPR $func_off + 0); break; }
done
test -n "$base" || \
f_panic "could not find base address for probe at $objfile($o)"
# Emit the record for the probe.
probes=$(f_add_record "$probes" \
"$type $provider $name $(($offset - $base)) $base $func_sym")
done
done <<EOF
$($NM $objfile | $EGREP " U $PROBE_REGEX" \
| $SED -E -e "s/.*$PROBE_REGEX.*/p \1 \2 \3/";
$NM $objfile | $EGREP " U $EPROBE_REGEX" \
| $SED -E -e "s/.*$EPROBE_REGEX.*/e \1 \2 \3/")
EOF
# Build the list of providers and of base probes from the probes.
while read type provider name offset base base_sym; do
providers=$(f_add_record "$providers" "$provider")
base_probes=$(f_add_record "$base_probes" "$provider $name $base $base_sym")
done <<EOF
$probes
EOF
providers=$(printf %s\\n "$providers" | $SORT | $UNIQ)
base_probes=$(printf %s\\n "$base_probes" | $SORT | $UNIQ)
}
# Collect the argument counts and type strings for all the probes
# described in the `probes' global variable. This is done by
# inspecting the d-script file provided by the user.
#
# This function sets the values of the following global variables.
# The values are structured in records, each record in a line. The
# fields of each record are separated in some cases by white
# characters and in other cases by colon (:) characters.
#
# The type codes in the line format descriptors are:
# S: string, D: decimal number
#
# probes_args
# Probes arguments.
# PROVIDER(S):NAME(S):NARGS(D):ARG1(S):ARG2(S):...:ARGn(S)
#
# Input globals:
# probes
# Output globals:
# probes_args
# Arguments:
# $1 is the d-script file from which to extract the arguments
# information.
f_collect_probes_args()
{
dscript=$1
while read type provider name offset base base_sym; do
# Process normal probes only. Is-enabled probes are not
# described in the d-script file and they don't receive any
# argument.
test "$type" = "p" || continue
# Names are mangled in d-script files to make it possible to
# have underscore characters as part of the provider name and
# probe name.
m_provider=$(printf %s $provider | $SED -e 's/_/__/g')
m_name=$(printf %s $name | $SED -e 's/_/__/g')
# Ignore this probe if the d-script file does not describe its
# provider.
$EGREP -q "provider +$m_provider" $dscript || continue
# Look for the line containing the description of the probe.
# If we can't find it then ignore this probe.
line=$($EGREP "^ *probe +$m_name *\(.*\);" $dscript)
test -n "$line" || continue
# Ok, extract the argument types from the probe prototype.
# This is fragile as hell as it requires the prototype to be
# in a single line.
args=""; nargs=0; line=$(printf %s "$line" | $SED -e 's/.*(\(.*\)).*/\1/')
set -f; IFS=,
for arg in $line; do
args="$args:$arg"
nargs=$((nargs + 1))
done
set +f; unset IFS
# Emit the record for the probe arguments.
probes_args=$(f_add_record "$probes_args" "$provider:$name:$nargs$args")
done <<EOF
$probes
EOF
}
# Functions to manipulate the global BCOUNT.
BCOUNT=0
f_incr_bcount()
{
BCOUNT=$((BCOUNT + $1))
}
f_align_bcount()
{
test $((BCOUNT % $1)) -eq 0 || BCOUNT=$((BCOUNT + ($1 - (BCOUNT % $1))))
}
# Generate a line of assembly code and add it to the asmprogram global
# variable.
#
# Arguments:
# $1 string to generate in a line.
asmprogram=
f_gen_asm()
{
line=$(printf "\t$1")
asmprogram=$(f_add_record "$asmprogram" "$line")
}
# Helper function to generate the assembly code of a DOF section
# header.
#
# This function is used by `f_gen_dof_program'.
#
# Arguments:
# $1 is the name of the described section.
# $2 is the type of the described section.
# $3 is the alignment of the described section.
# $4 is the number of entities stored in the described section.
# $5 is the offset in the DOF program of the described section.
# $6 is the size of the described section, in bytes.
f_gen_dof_sect_header()
{
f_gen_asm ""
f_gen_asm "/* dtrace_dof_sect for the $1 section. */"
f_gen_asm ".balign 8"
f_gen_asm ".4byte $2\t/* uint32_t dofs_type */"
f_gen_asm ".4byte $3\t/* uint32_t dofs_align */"
# The DOF_SECF_LOAD flag is 1 => loadable section.
f_gen_asm ".4byte 1\t/* uint32_t dofs_flags */"
f_gen_asm ".4byte $4\t/* uint32_t dofs_entsize */"
f_gen_asm ".8byte $5\t/* uint64_t dofs_offset */"
f_gen_asm ".8byte $6\t/* uint64_t dofs_size */"
}
# Generate a DOF program and assembly it in the output file.
#
# The DOF program generated by this function has the following
# structure:
#
# HEADER
# STRTAB OFFTAB EOFFTAB [PROBES PROVIDER]...
# STRTAB_SECT OFFTAB_SECT EOFFTAB_SECT ARGTAB_SECT [PROBES_SECT PROVIDER_SECT]...
#
# Input globals:
# probes, base_probes, providers, probes_args, BCOUNT
f_gen_dof_program()
{
###### Variables used to cache information needed later.
# Number of section headers in the generated DOF program.
dof_secnum=0
# Offset of section headers in the generated DOF program, in bytes.
dof_secoff=0
# Sizes of the STRTAB, OFFTAB and EOFFTAB sections, in bytes.
strtab_size=0
offtab_size=0
eofftab_size=0
# Offsets of the STRTAB, OFFTAB EOFFTAB and PROBES sections in the
# generated DOF program. In bytes.
strtab_offset=0
offtab_offset=0
eofftab_offset=0
argtab_offset=0
probes_offset=0
# Indexes of the section headers of the STRTAB, OFFTAB, EOFFTAB and
# PROBES sections in the sections array.
strtab_sect_index=0
offtab_sect_index=0
eofftab_sect_index=0
argtab_sect_index=0
probes_sect_index=0
# First offsets and eoffsets of the base-probes.
# Lines: PROVIDER(S) NAME(S) BASE(D) (DOF_OFFSET(D)|DOF_EOFFSET(D))
probes_dof_offsets=
probes_dof_eoffsets=
# Offsets in the STRTAB section for the first type of base probes.
# Record per line: PROVIDER(S) NAME(S) BASE(D) OFFSET(D)
probes_dof_types=
# Offsets of the provider names in the provider's STRTAB section.
# Lines: PROVIDER(S) OFFSET(D)
providers_dof_names=
# Offsets of the base-probe names in the provider's STRTAB section.
# Lines: PROVIDER(S) NAME(S) BASE(D) OFFSET(D)
probes_dof_names=
# Offsets of the provider sections in the DOF program.
# Lines: PROVIDER(S) OFFSET(D)
providers_offsets=
###### Generation phase.
# The header of the DOF program contains a `struct
# dtrace_dof_hdr'. Record its size, but it is written at the end
# of the function.
f_incr_bcount $dof_hdrsize; f_align_bcount 8
# The STRTAB section immediately follows the header. It contains
# the following set of packed null-terminated strings:
#
# [PROVIDER [BASE_PROBE_NAME [BASE_PROBE_ARG_TYPE...]]...]...
strtab_offset=$BCOUNT
strtab_sect_index=$dof_secnum
dof_secnum=$((dof_secnum + 1))
f_gen_asm ""
f_gen_asm "/* The STRTAB section. */"
f_gen_asm ".balign 8"
# Add the provider names.
off=0
while read provider; do
strtab_size=$(($strtab_size + ${#prov} + 1))
# Note the funny mangling...
f_gen_asm ".asciz \"$(printf %s $provider | $TR _ -)\""
providers_dof_names=$(f_add_record "$providers_dof_names" \
"$provider $off")
off=$(($off + ${#provider} + 1))
# Add the base-probe names.
while read p_provider name base base_sym; do
test "$p_provider" = "$provider" || continue
# And yes, more funny mangling...
f_gen_asm ".asciz \"$(printf %s $name | $TR _ -)\""
probes_dof_names=$(f_add_record "$probes_dof_names" \
"$p_provider $name $base $off")
off=$(($off + ${#name} + 1))
while read args; do
a_provider=$(printf %s "$args" | $CUT -d: -f1)
a_name=$(printf %s "$args" | $CUT -d: -f2)
test "$a_provider" = "$p_provider" \
&& test "$a_name" = "$name" \
|| continue
probes_dof_types=$(f_add_record "$probes_dof_types" \
"$a_provider $name $base $off")
nargs=$(printf %s "$args" | $CUT -d: -f3)
for n in $($SEQ $nargs); do
arg=$(printf %s "$args" | $CUT -d: -f$(($n + 3)))
f_gen_asm ".asciz \"${arg}\""
off=$(($off + ${#arg} + 1))
done
done <<EOF
$probes_args
EOF
done <<EOF
$base_probes
EOF
done <<EOF
$providers
EOF
strtab_size=$off
f_incr_bcount $strtab_size; f_align_bcount 8
# The OFFTAB section contains a set of 32bit words, one per
# defined regular probe.
offtab_offset=$BCOUNT
offtab_sect_index=$dof_secnum
dof_secnum=$((dof_secnum + 1))
f_gen_asm ""
f_gen_asm "/* The OFFTAB section. */"
f_gen_asm ".balign 8"
off=0
while read type provider name offset base base_sym; do
test "$type" = "p" || continue
f_gen_asm ".4byte $offset\t/* probe ${provider}:${name} */"
probes_dof_offsets=$(f_add_record "$probes_dof_offsets" \
"$provider $name $base $off")
off=$(($off + 4))
done <<EOF
$probes
EOF
offtab_size=$off
f_incr_bcount $offtab_size; f_align_bcount 8
# The EOFFTAB section contains a set of 32bit words, one per
# defined is-enabled probe.
eofftab_offset=$BCOUNT
eofftab_sect_index=$dof_secnum
dof_secnum=$((dof_secnum + 1))
f_gen_asm ""
f_gen_asm "/* The EOFFTAB section. */"
f_gen_asm ".balign 8"
off=0
while read type provider name offset base base_sym; do
test "$type" = "e" || continue
f_gen_asm ".4byte $offset\t/* is-enabled probe ${provider}:${name} */"
probes_dof_eoffsets=$(f_add_record "$probes_dof_eoffsets" \
"$provider $name $base $off")
off=$(($off + 4))
done <<EOF
$probes
EOF
eofftab_size=$off
f_incr_bcount $eofftab_size; f_align_bcount 8
# The ARGTAB section is empty, but nonetheless has a section
# header, so record its section index here.
argtab_offset=0
argtab_sect_index=$dof_secnum
dof_secnum=$((dof_secnum + 1))
# Generate a pair of sections PROBES and PROVIDER for each
# provider.
while read prov; do
# The PROBES section contains an array of `struct
# dtrace_dof_probe'.
#
# A `dtrace_dof_probe' entry characterizes the collection of
# probes and is-enabled probes sharing the same provider, name and
# base address.
probes_sect_index=$dof_secnum
dof_secnum=$((dof_secnum + 1))
probes_offset=$BCOUNT
num_base_probes=$(printf %s\\n "$base_probes" | $WC -l)
while read provider name base base_sym; do
name_offset=$(printf %s\\n "$probes_dof_names" \
| $EGREP "^$provider $name " | $CUT -d' ' -f4)
num_offsets=$(printf %s\\n "$probes_dof_offsets" \
| $EGREP "^$provider $name [0-9]+ " | $WC -l)
first_offset=0
test "$num_offsets" -gt 0 && \
first_offset=$(printf %s\\n "$probes_dof_offsets" \
| $EGREP "^$provider $name " | $CUT -d' ' -f4 | $HEAD -1)
num_eoffsets=$(printf %s\\n "$probes_dof_eoffsets" \
| $EGREP "^$provider $name [0-9]+ " | $WC -l)
first_eoffset=0
test "$num_eoffsets" -gt 0 && \
first_eoffset=$(printf %s "$probes_dof_eoffsets" \
| $EGREP "^$provider $name " | $CUT -d' ' -f4 | $HEAD -1)
num_args=$(printf %s "$probes_args" \
| $EGREP "^$provider:$name:" | $CUT -d: -f3 | $HEAD -1)
first_type=$(printf %s "$probes_dof_types" \
| $EGREP "^$provider $name $base " | $CUT -d' ' -f4 | $HEAD -1)
reloctype=R_X86_64_GLOB_DAT
test "$objbits" = "32" && reloctype=R_386_32
f_gen_asm ""
f_gen_asm "/* dtrace_dof_probe for ${provider}:${name} at ${base_sym} */"
f_gen_asm ".balign 8"
f_gen_asm ".reloc ., $reloctype, $base_sym + 0"
f_gen_asm ".8byte ${base}\t/* uint64_t dofpr_addr */"
f_gen_asm ".4byte 0\t/* uint32_t dofpr_func */"
f_gen_asm ".4byte $name_offset\t/* uint32_t dofpr_name */"
f_gen_asm ".4byte $first_type\t/* uint32_t dofpr_nargv */"
f_gen_asm ".4byte 0\t/* uint32_t dofpr_xargv */"
f_gen_asm ".4byte 0\t/* uint32_t dofpr_argidx */"
f_gen_asm ".4byte $(($first_offset/4))\t/* uint32_t dofpr_offidx */"
f_gen_asm ".byte $num_args\t/* uint8_t dofpr_nargc */"
f_gen_asm ".byte 0\t/* uint8_t dofpr_xargc */"
f_gen_asm ".2byte $num_offsets\t/* uint16_t dofpr_noffs */"
f_gen_asm ".4byte $(($first_eoffset/4))\t/* uint32_t dofpr_enoffidx */"
f_gen_asm ".2byte $num_eoffsets\t/* uint16_t dofpr_nenoffs */"
f_gen_asm ".2byte 0\t/* uint16_t dofpr_pad1 */"
f_gen_asm ".4byte 0\t/* uint16_t dofpr_pad2 */"
f_incr_bcount "$dof_probesize"
done <<EOF
$base_probes
EOF
# The PROVIDER section contains a `struct dtrace_dof_provider'
# instance describing the provider for the probes above.
dof_secnum=$((dof_secnum + 1))
providers_offsets=$(f_add_record "$providers_offsets" \
"$prov $BCOUNT")
# The dtrace_dof_provider.
provider_name_offset=$(printf %s "$providers_dof_names" \
| $EGREP "^$prov " | $CUT -d' ' -f2)
f_gen_asm ""
f_gen_asm "/* dtrace_dof_provider for $prov */"
f_gen_asm ".balign 8"
# Links to several DOF sections.
f_gen_asm ".4byte $strtab_sect_index\t/* uint32_t dofpv_strtab */"
f_gen_asm ".4byte $probes_sect_index\t/* uint32_t dofpv_probes */"
f_gen_asm ".4byte $argtab_sect_index\t/* uint32_t dofpv_prargs */"
f_gen_asm ".4byte $offtab_sect_index\t/* uint32_t dofpv_proffs */"
# Offset of the provider name into the STRTAB section.
f_gen_asm ".4byte $provider_name_offset\t/* uint32_t dofpv_name */"
# The rest of fields can be 0 for our modest purposes :)
f_gen_asm ".4byte 0\t/* uint32_t dofpv_provattr */"
f_gen_asm ".4byte 0\t/* uint32_t dofpv_modattr */"
f_gen_asm ".4byte 0\t/* uint32_t dofpv_funcattr */"
f_gen_asm ".4byte 0\t/* uint32_t dofpv_nameattr */"
f_gen_asm ".4byte 0\t/* uint32_t dofpv_argsattr */"
# But not this one, of course...
f_gen_asm ".4byte $eofftab_sect_index\t/* uint32_t dofpv_prenoffs */"
f_incr_bcount $dof_providersize
done<<EOF
$providers
EOF
f_align_bcount 8
# The section headers follow, one per section defined above.
dof_secoff=$BCOUNT
f_gen_dof_sect_header STRTAB \
$dof_sect_type_strtab \
1 1 $strtab_offset $strtab_size
f_incr_bcount $dof_secsize; f_align_bcount 8
f_gen_dof_sect_header OFFTAB \
$dof_sect_type_proffs \
4 4 $offtab_offset $offtab_size
f_incr_bcount $dof_secsize; f_align_bcount 8
f_gen_dof_sect_header EOFFTAB \
$dof_sect_type_prenoffs \
4 4 $eofftab_offset $eofftab_size
f_incr_bcount $dof_secsize; f_align_bcount 8
f_gen_dof_sect_header ARGTAB \
$dof_sect_type_prargs \
4 1 $argtab_offset 0
f_incr_bcount $dof_secsize; f_align_bcount 8
while read provider; do
provider_offset=$(printf %s "$providers_offsets" \
| $EGREP "^$provider " | $CUT -d' ' -f2)
num_base_probes=$(printf %s\\n "$base_probes" | $WC -l)
f_gen_dof_sect_header "$provider probes" \
$dof_sect_type_probes \
8 $dof_probesize $probes_offset \
$((num_base_probes * dof_probesize))
f_incr_bcount $dof_secsize; f_align_bcount 8
f_gen_dof_sect_header "$provider provider" \
$dof_sect_type_provider \
8 1 $provider_offset $dof_providersize
f_incr_bcount $dof_secsize; f_align_bcount 8
done <<EOF
$providers
EOF
# Finally, cook the header.
asmbody="$asmprogram"
asmprogram=""
f_gen_asm "/* File generated by pdtrace. */"
f_gen_asm ""
f_gen_asm ".section .SUNW_dof,\"a\",\"progbits\""
f_gen_asm ".globl __SUNW_dof"
f_gen_asm ".hidden __SUNW_dof"
f_gen_asm ".size __SUNW_dof, ${BCOUNT}"
f_gen_asm ".type __SUNW_dof, @object"
f_gen_asm "__SUNW_dof:"
f_gen_asm ""
f_gen_asm "/* dtrace_dof_hdr */"
f_gen_asm ".balign 8"
f_gen_asm ".byte 0x7f, 'D, 'O, 'F\t/* dofh_ident[0..3] */"
f_gen_asm ".byte 2\t\t/* model: 1=ILP32, 2=LP64 */"
f_gen_asm ".byte 1\t\t/* encoding: 1: little-endian, 2: big-endian */"
f_gen_asm ".byte 2\t\t/* DOF version: 1 or 2. Latest is 2 */"
f_gen_asm ".byte 2\t\t/* DIF version: 1 or 2. Latest is 2 */"
f_gen_asm ".byte 8\t\t/* number of DIF integer registers */"
f_gen_asm ".byte 8\t\t/* number of DIF tuple registers */"
f_gen_asm ".byte 0, 0\t\t/* dofh_ident[10..11] */"
f_gen_asm ".4byte 0\t\t/* dofh_ident[12..15] */"
f_gen_asm ".4byte 0\t/* uint32_t dofh_flags */" # See Limitations above.
f_gen_asm ".4byte ${dof_hdrsize}\t/* uint32_t dofh_hdrsize */"
f_gen_asm ".4byte ${dof_secsize}\t/* uint32_t dofh_secsize */"
f_gen_asm ".4byte ${dof_secnum}\t/* uint32_t dofh_secnum */"
f_gen_asm ".8byte ${dof_secoff}\t/* uint64_t dofh_secoff */"
f_gen_asm ".8byte ${BCOUNT}\t/* uint64_t dofh_loadsz */"
f_gen_asm ".8byte ${BCOUNT}\t/* uint64_t dofh_filesz */"
f_gen_asm ".8byte 0\t/* uint64_t dofh_pad */"
f_gen_asm ""
# Ok, now assembly the program in OFILE
echo "$asmprogram$asmbody" | $AS -$objbits -o $ofile
# Next step is to change the sh_type of the ".SUNW_dof" section
# headers to 0x6ffffff4 (SHT_SUNW_dof).
#
# Note that this code relies in the fact that readelf will list
# the sections ordered in the same order than the section headers
# in the section header table of the file.
elfinfo=$($READELF -a $ofile)
# Mind the endianness.
if printf %s "$elfinfo" | $EGREP -q "little endian"; then
sht_sunw_dof=$(printf %s%s%s%s \\364 \\377 \\377 \\157)
else
sht_sunw_dof=$(printf %s%s%s%s \\157 \\377 \\377 \\364)
fi
shdr_start=$(printf %s "$elfinfo" \
| $EGREP "^[ \t]*Start of section headers:" \
| $SED -E -e 's/.*headers:[ \t]*([0-9]+).*/\1/')
test -n "$shdr_start" \
|| f_panic "could not extract the start of shdr from $ofile"
shdr_num_entries=$(printf %s "$elfinfo" \
| $EGREP "^[ \t]*Size of section headers:" \
| $SED -E -e 's/.*headers:[ \t]*([0-9]+).*/\1/')
test -n "$shdr_num_entries" \
|| f_panic "could not extract the number of shdr entries from $ofile"
shdr_entry_size=$(printf %s "$elfinfo" \
| $EGREP "^[ \t]*Size of section headers:" \
| $SED -E -e 's/.*headers:[ \t]*([0-9]+).*/\1/')
test -n "$shdr_entry_size" \
|| f_panic "could not fetch the size of section headers from $ofile"
while read line; do
data=$(printf %s "$line" \
| $SED -E -e 's/.*\[(.*)\][ \t]+([a-zA-Z_.]+).*/\1:\2/')
num=$(printf %s "$data" | $CUT -d: -f1)
name=$(printf %s "$data" | $CUT -d: -f2)
if test "$name" = ".SUNW_dof"; then
# Patch the new sh_type in the proper entry of the section
# header table.
printf "$sht_sunw_dof" \
| dd of=$ofile conv=notrunc count=4 ibs=1 bs=1 \
seek=$((shdr_start + (shdr_entry_size * num) + 4)) \
2> /dev/null
break
fi
done <<EOF
$(printf %s "$elfinfo" | $EGREP "^[ \t]*\[[0-9 ]+\].*[A-Z]+.*PROGBITS")
EOF
}
# Patch the probed points in the given object file, replacing the
# function calls with NOPs.
#
# The probed points in the input object files are function calls.
# This function replaces these function calls by some other
# instruction sequences. Which replacement to use depends on several
# factors, as documented below.
#
# Arguments:
# $1 is the object file to patch.
f_patch_objfile()
{
objfile=$1
# Several x86_64 instruction opcodes, in octal.
x86_op_nop=$(printf \\220)
x86_op_ret=$(printf \\303)
x86_op_call=$(printf \\350)
x86_op_jmp32=$(printf \\351)
x86_op_rex_rax=$(printf \\110)
x86_op_xor_eax_0=$(printf \\063)
x86_op_xor_eax_1=$(printf \\300)
# Figure out the file offset of the text section in the object
# file.
text_off=0x$(objdump -j .text -h $objfile \
| grep \.text | $TR -s ' ' | $CUT -d' ' -f 7)
while read type provider name offset base base_sym; do
# Calculate the offset of the probed point in the object file.
# Note that the `offset' of is-enabled probes is tweaked in
# `f_collect_probes" to point ahead the patching point.
probe_off=$((text_off + base + offset))
if test "$type" = "e"; then
if test "$objbits" -eq "32"; then
probe_off=$((probe_off - 2))
else # 64 bits
probe_off=$((probe_off - 3))
fi
fi
# The probed point can be either a CALL instruction or a JMP
# instruction (a tail call). This has an impact on the
# patching sequence. Fetch the first byte at the probed point
# and do the right thing.
nopret="$x86_op_nop"
byte=$(dd if=$objfile count=1 ibs=1 bs=1 skip=$probe_off 2> /dev/null)
test "$byte" = "$x86_op_jmp32" && nopret="$x86_op_ret"
# Determine the patching sequence. It depends on the type of
# probe at hand (regular or is-enabled) and also if
# manipulating a 32bit or 64bit binary.
patchseq=
case $type in
p) patchseq=$(printf %s%s%s%s%s \
"$nopret" \
"$x86_op_nop" \
"$x86_op_nop" \
"$x86_op_nop" \
"$x86_op_nop")
;;
e) test "$objbits" -eq 64 && \
patchseq=$(printf %s%s%s%s%s \
"$x86_op_rex_rax" \
"$x86_op_xor_eax_0" \
"$x86_op_xor_eax_1" \
"$nopret" \
"$x86_op_nop")
test "$objbits" -eq 32 && \
patchseq=$(printf %s%s%s%s%s \
"$x86_op_xor_eax_0" \
"$x86_op_xor_eax_1" \
"$nopret" \
"$x86_op_nop" \
"$x86_op_nop")
;;
*) f_panic "internal error: wrong probe type $type";;
esac
# Patch!
printf %s "$patchseq" \
| dd of=$objfile conv=notrunc count=5 ibs=1 bs=1 seek=$probe_off 2> /dev/null
done <<EOF
$probes
EOF
# Finally, we have to remove the __dtrace_* and __dtraceenabled_*
# symbols from the object file, along with their respective
# relocations.
#
# Note that the most obvious call:
# strip -v -N whatever -w foo.o
# will not work:
# strip: not stripping symbol `whatever' because it is named in a relocation
#
# Fortunately using `-K !whatever' instead tricks strip to do the
# right thing, but this is black magic and may eventually stop
# working...
$STRIP -K '!__dtrace_*' -w $objfile
$STRIP -K '!__dtraceenabled_*' -w $objfile
}
# Read the input .d file and print a header file with macros to
# invoke the probes defined in it.
f_gen_header_file()
{
guard=$(basename $ofile | $TR - _ | $CUT -d. -f1 | $TR a-z A-Z)
printf "/*\n * Generated by pdtrace.\n */\n\n"
printf "#ifndef _${guard}_H\n"
printf "#define _${guard}_H\n\n"
printf "#include <unistd.h>\n"
printf "#include <inttypes.h>\n"
printf \\n\\n
printf "#ifdef __cplusplus\nextern \"C\" {\n#endif\n"
printf "#define _DTRACE_VERSION 1\n\n"
provider=$(cat $dfile | $EGREP "^ *provider +([a-zA-Z_]+)" \
| $SED -E -e 's/^ *provider +([a-zA-Z]+).*/\1/')
test -z "$provider" \
&& f_panic "unable to parse the provider name from $dfile."
u_provider=$(printf %s "$provider" | $TR a-z A-Z | $TR -s _)
cat $dfile | $EGREP "^ *probe +[a-zA-Z_]+ *\(.*\);" | \
while read line; do
# Extract the probe name.
name=$(printf %s "$line" \
| $SED -E -e 's/^ *probe +([a-zA-Z_]+).*/\1/')
u_name=$(printf %s "$name" | $TR a-z A-Z | $TR -s _)
# Generate an arg1,arg2,...,argN line for the probe.
args=""; nargs=0; aline=$(printf %s "$line" | $SED -e 's/.*(\(.*\)).*/\1/')
set -f; IFS=,
for arg in $aline; do
args="${args}arg${nargs},"
nargs=$((nargs + 1))
done
set +f; unset IFS
args=${args%,}
echo "#if _DTRACE_VERSION"
echo ""
# Emit the macros for the probe.
echo "#define ${u_provider}_${u_name}($args) \\"
echo " __dtrace_${provider}___${name}($args)"
echo "#define ${u_provider}_${u_name}_ENABLED() \\"
echo " __dtraceenabled_${provider}___${name}()"
# Emit the extern definitions for the probe dummy
# functions.
echo ""
printf %s\\n "$line" \
| $SED -E -e "s/^ *probe +/extern void __dtrace_${provider}___/"
echo "extern int __dtraceenabled_${provider}___${name}(void);"
printf "\n#else\n"
# Emit empty macros for the probe
echo "#define ${u_provider}_${u_name}($args)"
echo "#define ${u_provider}_${u_name}_ENABLED() (0)"
printf "\n#endif /* _DTRACE_VERSION */\n"
done
printf "#ifdef __cplusplus\n}\n#endif\n\n"
printf "#endif /* _${guard}_H */\n"
}
### Main program.
# Process command line arguments.
test "$#" -eq "0" && f_usage
genelf=0
genheader=0
objbits=64
ofile=
dfile=
while getopts VG3264hs:o: name; do
case $name in
V) f_version;;
s) dfile="$OPTARG";
test -f "$dfile" || f_panic "cannot read $dfile";;
o) ofile="$OPTARG";;
G) genelf=1;;
h) genheader=1;;
# Note the trick to support -32
3) objbits=666;;
2) test "$objbits" -eq 666 || f_usage; objbits=32;;
# Likewise for -64
6) objbits=777;;
4) test "$objbits" -eq 777 || f_usage; objbits=64;;
?) f_usage;;
esac
done
shift $(($OPTIND - 1))
test "$objbits" -eq "32" || test "$objbits" -eq "64" \
|| f_usage
test $((genelf + genheader)) -gt 1 && \
{ echo "Please use either -G or -h."; f_usage; }
test -n "$dfile" || { echo "Please specify a .d file with -s."; exit 2; }
if test "$genelf" -gt 0; then
# In this mode there must be a remaining argument: the name of the
# object file to inspect for probed points.
test "$#" -ne "1" && f_usage
test -f "$1" || f_panic "cannot read $1"
objfile=$1
# Collect probe information from the input object file and the
# d-script.
f_collect_probes $objfile
f_collect_probes_args $dfile
# Generate the assembly code and assemble the DOF program in
# OFILE. Then patch OBJFILE to remove the dummy probe calls.
f_gen_dof_program
f_patch_objfile $objfile
fi
if test "$genheader" -gt 0; then
test -n "$ofile" || { echo "Please specify an output file with -o."; exit 2; }
# In this mode no extra arguments shall be present.
test "$#" -ne "0" && f_usage
f_gen_header_file > $ofile
fi
# pdtrace ends here.