[PATCH 5/9] New probe type: DTrace USDT probes.

Jose E. Marchesi
2014-09-26T09:43:50Z

This patch adds a new type of probe to GDB: the DTrace USDT probes. The new
type is added by providing functions implementing all the entries of the
`probe_ops' structure defined in `probe.h'. The implementation is
self-contained and does not depend on DTrace source code in any way.

gdb:

2014-09-26 Jose E. Marchesi <jose.marchesi@oracle.com>

* breakpoint.c (BREAK_ARGS_HELP): help string updated to mention
the -probe-dtrace new vpossible value for PROBE_MODIFIER.

* configure.ac (CONFIG_OBS): dtrace-probe.o added if BFD can
handle ELF files.
* Makefile.in (SFILES): dtrace-probe.c added.
* configure: Regenerate.

* dtrace-probe.c: New file.
(SHT_SUNW_dof): New constant.
(dtrace_probe_type): New enum.
(dtrace_probe_arg): New struct.
(dtrace_probe_arg_s): New typedef.
(struct dtrace_probe_enabler): New struct.
(dtrace_probe_enabler_s): New typedef.
(dtrace_probe): New struct.
(dtrace_probe_is_linespec): New function.
(dtrace_dof_sect_type): New enum.
(DTRACE_DOF_ID_MAG0-3): New constants.
(DTRACE_DOF_ID_ENCODING): Likewise.
(DTRACE_DOF_ENCODE_LSB): Likewise.
(DTRACE_DOF_ENCODE_MSB): Likewise.
(dtrace_dof_hdr): New struct.
(dtrace_dof_sect): Likewise.
(dtrace_dof_provider): Likewise.
(dtrace_dof_probe): Likewise.
(DOF_UINT): New macro.
(DTRACE_DOF_PTR): Likewise.
(DTRACE_DOF_SECT): Likewise.
(dtrace_process_dof_probe): New function.
(dtrace_process_dof): Likewise.
(dtrace_build_arg_exprs): Likewise.
(dtrace_get_arg): Likewise.
(dtrace_get_probes): Likewise.
(dtrace_get_probe_argument_count): Likewise.
(dtrace_can_evaluate_probe_arguments): Likewise.
(dtrace_evaluate_probe_argument): Likewise.
(dtrace_compile_to_ax): Likewise.
(dtrace_set_semaphore): Likewise.
(dtrace_clear_semaphore): Likewise.
(dtrace_probe_destroy): Likewise.
(dtrace_gen_info_probes_table_header): Likewise.
(dtrace_gen_info_probes_table_values): Likewise.
(dtrace_probe_is_enabled): Likewise.
(dtrace_probe_ops): New variable.
(info_probes_dtrace_command): New function.
(_initialize_dtrace_probe): Likewise.
---
gdb/ChangeLog | 50 ++++
gdb/Makefile.in | 3 +-
gdb/breakpoint.c | 3 +-
gdb/configure | 2 +-
gdb/configure.ac | 2 +-
gdb/dtrace-probe.c | 816 ++++++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 872 insertions(+), 4 deletions(-)
create mode 100644 gdb/dtrace-probe.c

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7041cfb..eac03e7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,55 @@
2014-09-26 Jose E. Marchesi <jose.marchesi@oracle.com>

+ * breakpoint.c (BREAK_ARGS_HELP): help string updated to mention
+ the -probe-dtrace new vpossible value for PROBE_MODIFIER.
+
+ * configure.ac (CONFIG_OBS): dtrace-probe.o added if BFD can
+ handle ELF files.
+ * Makefile.in (SFILES): dtrace-probe.c added.
+ * configure: Regenerate.
+
+ * dtrace-probe.c: New file.
+ (SHT_SUNW_dof): New constant.
+ (dtrace_probe_type): New enum.
+ (dtrace_probe_arg): New struct.
+ (dtrace_probe_arg_s): New typedef.
+ (struct dtrace_probe_enabler): New struct.
+ (dtrace_probe_enabler_s): New typedef.
+ (dtrace_probe): New struct.
+ (dtrace_probe_is_linespec): New function.
+ (dtrace_dof_sect_type): New enum.
+ (DTRACE_DOF_ID_MAG0-3): New constants.
+ (DTRACE_DOF_ID_ENCODING): Likewise.
+ (DTRACE_DOF_ENCODE_LSB): Likewise.
+ (DTRACE_DOF_ENCODE_MSB): Likewise.
+ (dtrace_dof_hdr): New struct.
+ (dtrace_dof_sect): Likewise.
+ (dtrace_dof_provider): Likewise.
+ (dtrace_dof_probe): Likewise.
+ (DOF_UINT): New macro.
+ (DTRACE_DOF_PTR): Likewise.
+ (DTRACE_DOF_SECT): Likewise.
+ (dtrace_process_dof_probe): New function.
+ (dtrace_process_dof): Likewise.
+ (dtrace_build_arg_exprs): Likewise.
+ (dtrace_get_arg): Likewise.
+ (dtrace_get_probes): Likewise.
+ (dtrace_get_probe_argument_count): Likewise.
+ (dtrace_can_evaluate_probe_arguments): Likewise.
+ (dtrace_evaluate_probe_argument): Likewise.
+ (dtrace_compile_to_ax): Likewise.
+ (dtrace_set_semaphore): Likewise.
+ (dtrace_clear_semaphore): Likewise.
+ (dtrace_probe_destroy): Likewise.
+ (dtrace_gen_info_probes_table_header): Likewise.
+ (dtrace_gen_info_probes_table_values): Likewise.
+ (dtrace_probe_is_enabled): Likewise.
+ (dtrace_probe_ops): New variable.
+ (info_probes_dtrace_command): New function.
+ (_initialize_dtrace_probe): Likewise.
+
+2014-09-26 Jose E. Marchesi <jose.marchesi@oracle.com>
+
* gdbarch.sh (dtrace_probe_argument): New.
(dtrace_probe_is_enabled): Likewise.
(dtrace_enable_probe): Likewise.
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index cbec0d2..ad82215 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -799,7 +799,8 @@ SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c ada-tasks.c \
cp-abi.c cp-support.c cp-namespace.c cp-valprint.c \
d-exp.y d-lang.c d-support.c d-valprint.c \
cp-name-parser.y \
- dbxread.c demangle.c dictionary.c disasm.c doublest.c dummy-frame.c \
+ dbxread.c demangle.c dictionary.c disasm.c doublest.c \
+ dtrace-probe.c dummy-frame.c \
dwarf2expr.c dwarf2loc.c dwarf2read.c dwarf2-frame.c \
dwarf2-frame-tailcall.c \
elfread.c environ.c eval.c event-loop.c event-top.c \
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index bec7f68..95323bf 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -16197,7 +16197,8 @@ all_tracepoints (void)
command" [PROBE_MODIFIER] [LOCATION] [thread THREADNUM] [if CONDITION]\n\
PROBE_MODIFIER shall be present if the command is to be placed in a\n\
probe point. Accepted values are `-probe' (for a generic, automatically\n\
-guessed probe type) or `-probe-stap' (for a SystemTap probe).\n\
+guessed probe type), `-probe-stap' (for a SystemTap probe) or \n\
+`-probe-dtrace' (for a DTrace probe).\n\
LOCATION may be a line number, function name, or \"*\" and an address.\n\
If a line number is specified, break at start of code for that line.\n\
If a function is specified, break at start of code for that function.\n\
diff --git a/gdb/configure b/gdb/configure
index 6e7435f..ecd0cff 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -13281,7 +13281,7 @@ $as_echo "$gdb_cv_var_elf" >&6; }
LDFLAGS=$OLD_LDFLAGS
LIBS=$OLD_LIBS
if test $gdb_cv_var_elf = yes; then
- CONFIG_OBS="$CONFIG_OBS elfread.o stap-probe.o"
+ CONFIG_OBS="$CONFIG_OBS elfread.o stap-probe.o dtrace-probe.o"

$as_echo "#define HAVE_ELF 1" >>confdefs.h

diff --git a/gdb/configure.ac b/gdb/configure.ac
index 4f5fb7b..7b1133a 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -2103,7 +2103,7 @@ AC_SUBST(WIN32LIBS)
GDB_AC_CHECK_BFD([for ELF support in BFD], gdb_cv_var_elf,
[bfd_get_elf_phdr_upper_bound (NULL)], elf-bfd.h)
if test $gdb_cv_var_elf = yes; then
- CONFIG_OBS="$CONFIG_OBS elfread.o stap-probe.o"
+ CONFIG_OBS="$CONFIG_OBS elfread.o stap-probe.o dtrace-probe.o"
AC_DEFINE(HAVE_ELF, 1,
[Define if ELF support should be included.])
# -ldl is provided by bfd/Makfile.am (LIBDL) <PLUGINS>.
diff --git a/gdb/dtrace-probe.c b/gdb/dtrace-probe.c
new file mode 100644
index 0000000..f529ca5
--- /dev/null
+++ b/gdb/dtrace-probe.c
@@ -0,0 +1,816 @@
+/* DTrace probe support for GDB.
+
+ Copyright (C) 2014 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/>. */
+
+#include "defs.h"
+#include "probe.h"
+#include "vec.h"
+#include "elf-bfd.h"
+#include "gdbtypes.h"
+#include "obstack.h"
+#include "objfiles.h"
+#include "complaints.h"
+#include "value.h"
+#include "ax.h"
+#include "ax-gdb.h"
+#include "language.h"
+#include "parser-defs.h"
+#include "inferior.h"
+
+/* The type of the ELF sections where we will find the DOF programs
+ with information about probes. */
+
+#ifndef SHT_SUNW_dof
+# define SHT_SUNW_dof 0x6ffffff4
+#endif
+
+/* Forward declaration. */
+
+static const struct probe_ops dtrace_probe_ops;
+
+/* The following structure represents a single argument for the
+ probe. */
+
+struct dtrace_probe_arg
+{
+ /* The type of the probe argument. */
+ struct type *type;
+
+ /* A string describing the type. */
+ char *type_str;
+
+ /* The argument converted to an internal GDB expression. */
+ struct expression *expr;
+};
+
+typedef struct dtrace_probe_arg dtrace_probe_arg_s;
+DEF_VEC_O (dtrace_probe_arg_s);
+
+/* The following structure represents an enabler for a probe. */
+
+struct dtrace_probe_enabler
+{
+ /* Program counter where the is-enabled probe is installed. The
+ contents (nops, whatever...) stored at this address are
+ architecture dependent. */
+ CORE_ADDR address;
+};
+
+typedef struct dtrace_probe_enabler dtrace_probe_enabler_s;
+DEF_VEC_O (dtrace_probe_enabler_s);
+
+/* The following structure represents a dtrace probe. */
+
+struct dtrace_probe
+{
+ /* Generic information about the probe. This must be the first
+ element of this struct, in order to maintain binary compatibility
+ with the `struct probe' and be able to fully abstract it. */
+ struct probe p;
+
+ /* A probe can have zero or more arguments. */
+ int probe_argc;
+ VEC (dtrace_probe_arg_s) *args;
+
+ /* A probe can have zero or more "enablers" associated with it. */
+ VEC (dtrace_probe_enabler_s) *enablers;
+
+ /* Whether the expressions for the arguments have been built. */
+ int args_expr_built : 1;
+};
+
+/* Implementation of the probe_is_linespec method. */
+
+static int
+dtrace_probe_is_linespec (const char **linespecp)
+{
+ static const char *const keywords[] = { "-pdtrace", "-probe-dtrace", NULL };
+
+ return probe_is_linespec_by_keyword (linespecp, keywords);
+}
+
+/* DOF programs can contain an arbitrary number of sections of 26
+ different types. In order to support DTrace USDT probes we only
+ need to handle a subset of these section types, fortunately. These
+ section types are defined in the following enumeration.
+
+ See linux/dtrace/dof_defines.h for a complete list of section types
+ along with their values. */
+
+enum dtrace_dof_sect_type
+{
+ DTRACE_DOF_SECT_TYPE_NONE = 0,
+ DTRACE_DOF_SECT_TYPE_ECBDESC = 3,
+ DTRACE_DOF_SECT_TYPE_STRTAB = 8,
+ DTRACE_DOF_SECT_TYPE_PROVIDER = 15,
+ DTRACE_DOF_SECT_TYPE_PROBES = 16,
+ DTRACE_DOF_SECT_TYPE_PRARGS = 17,
+ DTRACE_DOF_SECT_TYPE_PROFFS = 18,
+ DTRACE_DOF_SECT_TYPE_PRENOFFS = 26
+};
+
+/* The following collection of data structures map the structure of
+ DOF entities. Again, we only cover the subset of DOF used to
+ implement USDT probes.
+
+ See linux/dtrace/dof.h header for a complete list of data
+ structures. */
+
+/* Indexes to use in `dofh_ident' below. */
+#define DTRACE_DOF_ID_MAG0 0
+#define DTRACE_DOF_ID_MAG1 1
+#define DTRACE_DOF_ID_MAG2 2
+#define DTRACE_DOF_ID_MAG3 3
+#define DTRACE_DOF_ID_ENCODING 5
+
+/* Possible values for dofh_ident[DOF_ID_ENCODING]. */
+#define DTRACE_DOF_ENCODE_LSB 1
+#define DTRACE_DOF_ENCODE_MSB 2
+
+struct dtrace_dof_hdr
+{
+ uint8_t dofh_ident[16];
+ uint32_t dofh_flags;
+ uint32_t dofh_hdrsize;
+ uint32_t dofh_secsize;
+ uint32_t dofh_secnum;
+ uint64_t dofh_secoff;
+ uint64_t dofh_loadsz;
+ uint64_t dofh_filesz;
+ uint64_t dofh_pad;
+};
+
+struct dtrace_dof_sect
+{
+ uint32_t dofs_type; /* See the enum dtrace_dof_sect above. */
+ uint32_t dofs_align;
+ uint32_t dofs_flags;
+ uint32_t dofs_entsize;
+ uint64_t dofs_offset; /* DOF + offset points to the section data. */
+ uint64_t dofs_size; /* Size of section data in bytes. */
+};
+
+struct dtrace_dof_provider
+{
+ uint32_t dofpv_strtab; /* Link to a DTRACE_DOF_SECT_TYPE_STRTAB section */
+ uint32_t dofpv_probes; /* Link to a DTRACE_DOF_SECT_TYPE_PROBES section */
+ uint32_t dofpv_prargs; /* Link to a DTRACE_DOF_SECT_TYPE_PRARGS section */
+ uint32_t dofpv_proffs; /* Link to a DTRACE_DOF_SECT_TYPE_PROFFS section */
+ uint32_t dofpv_name;
+ uint32_t dofpv_provattr;
+ uint32_t dofpv_modattr;
+ uint32_t dofpv_funcattr;
+ uint32_t dofpv_nameattr;
+ uint32_t dofpv_argsattr;
+ uint32_t dofpv_prenoffs; /* Link to a DTRACE_DOF_SECT_PRENOFFS section */
+};
+
+struct dtrace_dof_probe
+{
+ uint64_t dofpr_addr;
+ uint32_t dofpr_func;
+ uint32_t dofpr_name;
+ uint32_t dofpr_nargv;
+ uint32_t dofpr_xargv;
+ uint32_t dofpr_argidx;
+ uint32_t dofpr_offidx;
+ uint8_t dofpr_nargc;
+ uint8_t dofpr_xargc;
+ uint16_t dofpr_noffs;
+ uint32_t dofpr_enoffidx;
+ uint16_t dofpr_nenoffs;
+ uint16_t dofpr_pad1;
+ uint32_t dofpr_pad2;
+};
+
+/* DOF supports two different encodings: MSB (big-endian) and LSB
+ (little-endian). The encoding is itself encoded in the DOF header.
+ The following function returns an unsigned value in the host
+ endianness. */
+
+#define DOF_UINT(dof, field) \
+ extract_unsigned_integer ((gdb_byte *) &(field), \
+ sizeof ((field)), \
+ (((dof)->dofh_ident[DTRACE_DOF_ID_ENCODING] == DTRACE_DOF_ENCODE_MSB) \
+ ? BFD_ENDIAN_BIG : BFD_ENDIAN_LITTLE))
+
+/* The following macro applies a given byte offset to a DOF (a pointer
+ to a dtrace_dof_hdr structure) and returns the resulting
+ address. */
+
+#define DTRACE_DOF_PTR(dof, offset) (&((char *) (dof))[(offset)])
+
+/* The following macro returns a pointer to the beginning of a given
+ section in a DOF object. The section is referred to by its index
+ in the sections array. */
+
+#define DTRACE_DOF_SECT(dof, idx) \
+ ((struct dtrace_dof_sect *) \
+ DTRACE_DOF_PTR ((dof), \
+ DOF_UINT ((dof), (dof)->dofh_secoff) \
+ + ((idx) * DOF_UINT ((dof), (dof)->dofh_secsize))))
+
+/* Helper functions to extract the probe information from the DOF
+ object embedded in the .SUNW_dof section. */
+
+static void
+dtrace_process_dof_probe (struct objfile *objfile,
+ struct gdbarch *gdbarch, VEC (probe_p) **probesp,
+ struct dtrace_dof_hdr *dof, struct dtrace_dof_probe *probe,
+ struct dtrace_dof_provider *provider,
+ char *strtab, char *offtab, char *eofftab,
+ char *argtab, uint64_t strtab_size)
+{
+ struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
+ int i, j, num_probes, num_enablers;
+ VEC (dtrace_probe_enabler_s) *enablers;
+ char *p;
+
+ /* Each probe section can define zero or more probes of two
+ different types:
+
+ - probe->dofpr_noffs regular probes whose program counters are
+ stored in 32bit words starting at probe->dofpr_addr +
+ offtab[probe->dofpr_offidx].
+
+ - probe->dofpr_nenoffs is-enabled probes whose program counters
+ are stored in 32bit words starting at probe->dofpr_addr +
+ eofftab[probe->dofpr_enoffidx].
+
+ However is-enabled probes are not probes per-se, but an
+ optimization hack that is implemented in the kernel in a very
+ similar way than normal probes. This is how we support
+ is-enabled probes on gdb:
+
+ - Our probes are always DTrace regular probes.
+
+ - Our probes can be associated with zero or more "enablers". The
+ list of enablers is built from the is-enabled probes defined in
+ the Probe section.
+
+ - Probes having a non-empty list of enablers can be enabled or
+ disabled using the `enable probe' and `disable probe' commands
+ respectively. The `Enabled' column in the output of `info
+ probes' will read `yes' if the enablers are activated, `no'
+ otherwise.
+
+ - Probes having an empty list of enablers are always enabled.
+ The `Enabled' column in the output of `info probes' will
+ read `always'.
+
+ It follows that if there are DTrace is-enabled probes defined for
+ some provider/name but no DTrace regular probes defined then the
+ gdb user wont be able to enable/disable these conditionals. */
+
+ num_probes = DOF_UINT (dof, probe->dofpr_noffs);
+ if (num_probes == 0)
+ return;
+
+ /* Build the list of enablers for the probes defined in this Probe
+ DOF section. */
+ enablers = NULL;
+ num_enablers = DOF_UINT (dof, probe->dofpr_nenoffs);
+ for (i = 0; i < num_enablers; i++)
+ {
+ struct dtrace_probe_enabler enabler;
+ uint32_t enabler_offset
+ = ((uint32_t *) eofftab)[DOF_UINT (dof, probe->dofpr_enoffidx) + i];
+
+ enabler.address = DOF_UINT (dof, probe->dofpr_addr) + DOF_UINT (dof, enabler_offset);
+ VEC_safe_push (dtrace_probe_enabler_s, enablers, &enabler);
+ }
+
+ for (i = 0; i < num_probes; i++)
+ {
+ uint32_t probe_offset
+ = ((uint32_t *) offtab)[DOF_UINT (dof, probe->dofpr_offidx) + i];
+ struct dtrace_probe *ret
+ = obstack_alloc (&objfile->per_bfd->storage_obstack, sizeof (*ret));
+
+ ret->p.pops = &dtrace_probe_ops;
+ ret->p.arch = gdbarch;
+ ret->args_expr_built = 0;
+
+ /* Set the provider and the name of the probe. */
+ ret->p.provider = xstrdup (strtab + DOF_UINT (dof, provider->dofpv_name));
+ ret->p.name = xstrdup (strtab + DOF_UINT (dof, probe->dofpr_name));
+
+ /* The probe address. */
+ ret->p.address = DOF_UINT (dof, probe->dofpr_addr) + DOF_UINT (dof, probe_offset);
+
+ /* Number of arguments in the probe. */
+ ret->probe_argc = DOF_UINT (dof, probe->dofpr_nargc);
+
+ /* Store argument type descriptions. A description of the type
+ of the argument is in the (J+1)th null-terminated string
+ starting at `strtab' + `probe->dofpr_nargv'. */
+ ret->args = NULL;
+ p = strtab + DOF_UINT (dof, probe->dofpr_nargv);
+ for (j = 0; j < ret->probe_argc; j++)
+ {
+ struct dtrace_probe_arg arg;
+ struct expression *expr;
+
+ arg.type_str = xstrdup (p);
+ while (((p - strtab) < strtab_size) /* sentinel. */
+ && *p++);
+
+ /* Try to parse a type expression from the type string. If
+ this does not work then we set the type to `long
+ int'. */
+ arg.type = builtin_type (gdbarch)->builtin_long;
+ expr = parse_expression (arg.type_str);
+ if (expr->elts[0].opcode == OP_TYPE)
+ arg.type = expr->elts[1].type;
+
+ VEC_safe_push (dtrace_probe_arg_s, ret->args, &arg);
+ }
+
+ /* Add the vector of enablers to this probe, if any. */
+ ret->enablers = VEC_copy (dtrace_probe_enabler_s, enablers);
+
+ /* Successfully created probe. */
+ VEC_safe_push (probe_p, *probesp, (struct probe *) ret);
+ }
+}
+
+static void
+dtrace_process_dof (asection *sect, struct objfile *objfile,
+ VEC (probe_p) **probesp, struct dtrace_dof_hdr *dof)
+{
+ bfd *abfd = objfile->obfd;
+ int size = bfd_get_arch_size (abfd) / 8;
+ struct gdbarch *gdbarch = get_objfile_arch (objfile);
+ struct dtrace_dof_sect *section;
+ int i;
+
+ /* The first step is to check for the DOF magic number. If no valid
+ DOF data is found in the section then a complaint is issued to
+ the user and the section skipped. */
+ if ((dof->dofh_ident[DTRACE_DOF_ID_MAG0] != 0x7F)
+ || (dof->dofh_ident[DTRACE_DOF_ID_MAG1] != 'D')
+ || (dof->dofh_ident[DTRACE_DOF_ID_MAG2] != 'O')
+ || (dof->dofh_ident[DTRACE_DOF_ID_MAG3] != 'F'))
+ goto invalid_dof_data;
+
+ /* Make sure this DOF is not an enabling DOF, i.e. there are no ECB
+ Description sections. */
+ section = (struct dtrace_dof_sect *) DTRACE_DOF_PTR (dof,
+ DOF_UINT (dof, dof->dofh_secoff));
+ for (i = 0; i < DOF_UINT (dof, dof->dofh_secnum); i++, section++)
+ if (section->dofs_type == DTRACE_DOF_SECT_TYPE_ECBDESC)
+ return;
+
+ /* Iterate over any section of type Provider and extract the probe
+ information from them. If there are no "provider" sections on
+ the DOF then we just return. */
+ section = (struct dtrace_dof_sect *) DTRACE_DOF_PTR (dof,
+ DOF_UINT (dof, dof->dofh_secoff));
+ for (i = 0; i < DOF_UINT (dof, dof->dofh_secnum); i++, section++)
+ if (DOF_UINT (dof, section->dofs_type) == DTRACE_DOF_SECT_TYPE_PROVIDER)
+ {
+ struct dtrace_dof_provider *provider = (struct dtrace_dof_provider *)
+ DTRACE_DOF_PTR (dof, DOF_UINT (dof, section->dofs_offset));
+
+ struct dtrace_dof_sect *strtab_s
+ = DTRACE_DOF_SECT (dof, DOF_UINT (dof, provider->dofpv_strtab));
+ struct dtrace_dof_sect *probes_s
+ = DTRACE_DOF_SECT (dof, DOF_UINT (dof, provider->dofpv_probes));
+ struct dtrace_dof_sect *args_s
+ = DTRACE_DOF_SECT (dof, DOF_UINT (dof, provider->dofpv_prargs));
+ struct dtrace_dof_sect *offsets_s
+ = DTRACE_DOF_SECT (dof, DOF_UINT (dof, provider->dofpv_proffs));
+ struct dtrace_dof_sect *eoffsets_s
+ = DTRACE_DOF_SECT (dof, DOF_UINT (dof, provider->dofpv_prenoffs));
+
+ char *strtab = DTRACE_DOF_PTR (dof, DOF_UINT (dof, strtab_s->dofs_offset));
+ char *offtab = DTRACE_DOF_PTR (dof, DOF_UINT (dof, offsets_s->dofs_offset));
+ char *eofftab = DTRACE_DOF_PTR (dof, DOF_UINT (dof, eoffsets_s->dofs_offset));
+ char *argtab = DTRACE_DOF_PTR (dof, DOF_UINT (dof, args_s->dofs_offset));
+
+ unsigned int entsize = DOF_UINT (dof, probes_s->dofs_entsize);
+ int num_probes;
+
+ /* Very, unlikely, but could crash gdb if not handled
+ properly. */
+ if (entsize == 0)
+ goto invalid_dof_data;
+
+ num_probes = DOF_UINT (dof, probes_s->dofs_size) / entsize;
+
+ for (i = 0; i < num_probes; i++)
+ {
+ struct dtrace_dof_probe *probe = (struct dtrace_dof_probe *)
+ DTRACE_DOF_PTR (dof, DOF_UINT (dof, probes_s->dofs_offset)
+ + (i * DOF_UINT (dof, probes_s->dofs_entsize)));
+ dtrace_process_dof_probe (objfile,
+ gdbarch, probesp,
+ dof, probe,
+ provider, strtab, offtab, eofftab, argtab,
+ DOF_UINT (dof, strtab_s->dofs_size));
+ }
+ }
+
+ return;
+
+ invalid_dof_data:
+ complaint (&symfile_complaints,
+ _("skipping section '%s' which does not contain valid DOF data."),
+ sect->name);
+ return;
+}
+
+/* Helper functions to make sure the expressions in the arguments
+ array are built as soon as their values are needed. */
+
+static void
+dtrace_build_arg_exprs (struct dtrace_probe *probe,
+ struct gdbarch *gdbarch)
+{
+ struct parser_state pstate;
+ struct cleanup *back_to;
+ struct dtrace_probe_arg *arg;
+ int i;
+
+ probe->args_expr_built = 1;
+
+ /* Iterate over the arguments in the probe and build the
+ corresponding GDB internal expression that will generate the
+ value of the argument when executed at the PC of the probe. */
+ for (i = 0; i < probe->probe_argc; i++)
+ {
+ arg = VEC_index (dtrace_probe_arg_s, probe->args, i);
+
+ /* Initialize the expression buffer in the parser state. The
+ language does not matter, since we are using our own
+ parser. */
+ initialize_expout (&pstate, 10, current_language, gdbarch);
+ back_to = make_cleanup (free_current_contents, &pstate.expout);
+
+ /* The argument value, which is ABI dependent and casted to
+ `long int'. */
+ gdbarch_dtrace_probe_argument (gdbarch, &pstate, i);
+
+ discard_cleanups (back_to);
+
+ /* Casting to the expected type, but only if the type was
+ recognized at probe load time. Otherwise the argument will
+ be evaluated as the long integer passed to the probe. */
+ if (arg->type)
+ {
+ write_exp_elt_opcode (&pstate, UNOP_CAST);
+ write_exp_elt_type (&pstate, arg->type);
+ write_exp_elt_opcode (&pstate, UNOP_CAST);
+ }
+
+ reallocate_expout (&pstate);
+ arg->expr = pstate.expout;
+ prefixify_expression (arg->expr);
+ }
+}
+
+static struct dtrace_probe_arg *
+dtrace_get_arg (struct dtrace_probe *probe, unsigned n,
+ struct gdbarch *gdbarch)
+{
+ if (!probe->args_expr_built)
+ dtrace_build_arg_exprs (probe, gdbarch);
+
+ return VEC_index (dtrace_probe_arg_s, probe->args, n);
+}
+
+/* Implementation of the get_probes method. */
+
+static void
+dtrace_get_probes (VEC (probe_p) **probesp, struct objfile *objfile)
+{
+ bfd *abfd = objfile->obfd;
+ asection *sect = NULL;
+
+ /* Do nothing in case this is a .debug file, instead of the objfile
+ itself. */
+ if (objfile->separate_debug_objfile_backlink != NULL)
+ return;
+
+ /* Iterate over the sections in OBJFILE looking for DTrace
+ information. */
+ for (sect = abfd->sections; sect != NULL; sect = sect->next)
+ {
+ if (elf_section_data (sect)->this_hdr.sh_type == SHT_SUNW_dof)
+ {
+ struct dtrace_dof_hdr *dof;
+
+ /* Read the contents of the DOF section and then process it to
+ extract the information of any probe defined into it. */
+ if (!bfd_malloc_and_get_section (abfd, sect, (bfd_byte **) &dof))
+ {
+ complaint (&symfile_complaints,
+ _("could not obtain the contents of"
+ "section '%s' in objfile `%s'."),
+ sect->name, abfd->filename);
+ return;
+ }
+
+ dtrace_process_dof (sect, objfile, probesp, dof);
+ xfree (dof);
+ }
+ }
+}
+
+/* Helper function to determine whether a given probe is "enabled" or
+ "disabled". A disabled probe is a probe in which one or more
+ enablers are disabled. */
+
+static int
+dtrace_probe_is_enabled (struct dtrace_probe *probe)
+{
+ int i;
+ struct gdbarch *gdbarch = probe->p.arch;
+ struct dtrace_probe_enabler *enabler;
+
+ for (i = 0; VEC_iterate (dtrace_probe_enabler_s, probe->enablers, i, enabler); i++)
+ if (!gdbarch_dtrace_probe_is_enabled (gdbarch, enabler->address))
+ return 0;
+
+ return 1;
+}
+
+/* Implementation of the get_probe_address method. */
+
+static CORE_ADDR
+dtrace_get_probe_address (struct probe *probe, struct objfile *objfile)
+{
+ return probe->address + ANOFFSET (objfile->section_offsets,
+ SECT_OFF_DATA (objfile));
+}
+
+/* Implementation of the get_probe_argument_count method. */
+
+static unsigned
+dtrace_get_probe_argument_count (struct probe *probe_generic,
+ struct frame_info *frame)
+{
+ struct dtrace_probe *dtrace_probe = (struct dtrace_probe *) probe_generic;
+
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+
+ return dtrace_probe->probe_argc;
+}
+
+/* Implementation of the can_evaluate_probe_arguments method. */
+
+static int
+dtrace_can_evaluate_probe_arguments (struct probe *probe_generic)
+{
+ struct gdbarch *gdbarch = probe_generic->arch;
+
+ return gdbarch_dtrace_probe_argument_p (gdbarch);
+}
+
+/* Implementation of the evaluate_probe_argument method. */
+
+static struct value *
+dtrace_evaluate_probe_argument (struct probe *probe_generic, unsigned n,
+ struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = probe_generic->arch;
+ struct dtrace_probe *dtrace_probe = (struct dtrace_probe *) probe_generic;
+ struct dtrace_probe_arg *arg;
+ int pos = 0;
+
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+
+ arg = dtrace_get_arg (dtrace_probe, n, gdbarch);
+ return evaluate_subexp_standard (arg->type, arg->expr, &pos, EVAL_NORMAL);
+}
+
+/* Implementation of the compile_to_ax method. */
+
+static void
+dtrace_compile_to_ax (struct probe *probe_generic, struct agent_expr *expr,
+ struct axs_value *value, unsigned n)
+{
+ struct dtrace_probe *dtrace_probe = (struct dtrace_probe *) probe_generic;
+ struct dtrace_probe_arg *arg;
+ union exp_element *pc;
+
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+
+ arg = dtrace_get_arg (dtrace_probe, n, expr->gdbarch);
+
+ pc = arg->expr->elts;
+ gen_expr (arg->expr, &pc, expr, value);
+
+ require_rvalue (expr, value);
+ value->type = arg->type;
+}
+
+/* Implementation of the set_semaphore method. */
+
+static void
+dtrace_set_semaphore (struct probe *probe_generic, struct objfile *objfile,
+ struct gdbarch *gdbarch)
+{
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+}
+
+/* Implementation of the clear_semaphore method. */
+
+static void
+dtrace_clear_semaphore (struct probe *probe_generic, struct objfile *objfile,
+ struct gdbarch *gdbarch)
+{
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+}
+
+/* Implementation of the probe_destroy method. */
+
+static void
+dtrace_probe_destroy (struct probe *probe_generic)
+{
+ struct dtrace_probe *probe = (struct dtrace_probe *) probe_generic;
+ struct dtrace_probe_arg *arg;
+ int i;
+
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+
+ for (i = 0; VEC_iterate (dtrace_probe_arg_s, probe->args, i, arg); i++)
+ {
+ xfree (arg->type_str);
+ xfree (arg->expr);
+ }
+
+ VEC_free (dtrace_probe_enabler_s, probe->enablers);
+ VEC_free (dtrace_probe_arg_s, probe->args);
+}
+
+/* Implementation of the gen_info_probes_table_header method. */
+
+static void
+dtrace_gen_info_probes_table_header (VEC (info_probe_column_s) **heads)
+{
+ info_probe_column_s dtrace_probe_column;
+
+ dtrace_probe_column.field_name = "enabled";
+ dtrace_probe_column.print_name = _("Enabled");
+
+ VEC_safe_push (info_probe_column_s, *heads, &dtrace_probe_column);
+}
+
+/* Implementation of the gen_info_probes_table_values method. */
+
+static void
+dtrace_gen_info_probes_table_values (struct probe *probe_generic,
+ VEC (const_char_ptr) **ret)
+{
+ struct dtrace_probe *probe = (struct dtrace_probe *) probe_generic;
+ const char *val = NULL;
+
+ gdb_assert (probe_generic->pops == &dtrace_probe_ops);
+
+ if (VEC_empty (dtrace_probe_enabler_s, probe->enablers))
+ val = "always";
+ else if (!gdbarch_dtrace_probe_is_enabled_p (probe_generic->arch))
+ val = "unknown";
+ else if (dtrace_probe_is_enabled (probe))
+ val = "yes";
+ else
+ val = "no";
+
+ VEC_safe_push (const_char_ptr, *ret, val);
+}
+
+/* Implementation of the enable_probe method. */
+
+static void
+dtrace_enable_probe (struct probe *probe)
+{
+ struct gdbarch *gdbarch = probe->arch;
+ struct dtrace_probe *dtrace_probe = (struct dtrace_probe *) probe;
+ struct dtrace_probe_enabler *enabler;
+ int i;
+
+ gdb_assert (probe->pops == &dtrace_probe_ops);
+
+ /* Enabling a dtrace probe implies patching the text section of the
+ running process, so make sure the inferior is indeed running. */
+ if (ptid_equal (inferior_ptid, null_ptid))
+ error (_("No inferior running"));
+
+ /* Fast path. */
+ if (dtrace_probe_is_enabled (dtrace_probe))
+ return;
+
+ /* Iterate over all defined enabler in the given probe and enable
+ them all using the corresponding gdbarch hook. */
+
+ for (i = 0;
+ VEC_iterate (dtrace_probe_enabler_s, dtrace_probe->enablers, i, enabler);
+ i++)
+ {
+ if (gdbarch_dtrace_enable_probe_p (gdbarch))
+ gdbarch_dtrace_enable_probe (gdbarch, enabler->address);
+ }
+}
+
+
+/* Implementation of the disable_probe method. */
+
+static void
+dtrace_disable_probe (struct probe *probe)
+{
+ struct gdbarch *gdbarch = probe->arch;
+ struct dtrace_probe *dtrace_probe = (struct dtrace_probe *) probe;
+ struct dtrace_probe_enabler *enabler;
+ int i;
+
+ gdb_assert (probe->pops == &dtrace_probe_ops);
+
+ /* Disabling a dtrace probe implies patching the text section of the
+ running process, so make sure the inferior is indeed running. */
+ if (ptid_equal (inferior_ptid, null_ptid))
+ error (_("No inferior running"));
+
+ /* Fast path. */
+ if (!dtrace_probe_is_enabled (dtrace_probe))
+ return;
+
+ /* Are we trying to disable a probe that does not have any enabler
+ associated? */
+ if (VEC_empty (dtrace_probe_enabler_s, dtrace_probe->enablers))
+ error (_("Probe %s:%s cannot be disabled."), probe->provider, probe->name);
+
+ /* Iterate over all defined enabler in the given probe and disable
+ them all using the corresponding gdbarch hook. */
+
+ for (i = 0;
+ VEC_iterate (dtrace_probe_enabler_s, dtrace_probe->enablers, i, enabler);
+ i++)
+ {
+ if (gdbarch_dtrace_disable_probe_p (gdbarch))
+ gdbarch_dtrace_disable_probe (gdbarch, enabler->address);
+ }
+}
+
+/* DTrace probe_ops. */
+
+static const struct probe_ops dtrace_probe_ops =
+{
+ dtrace_probe_is_linespec,
+ dtrace_get_probes,
+ dtrace_get_probe_address,
+ dtrace_get_probe_argument_count,
+ dtrace_can_evaluate_probe_arguments,
+ dtrace_evaluate_probe_argument,
+ dtrace_compile_to_ax,
+ dtrace_set_semaphore,
+ dtrace_clear_semaphore,
+ dtrace_probe_destroy,
+ dtrace_gen_info_probes_table_header,
+ dtrace_gen_info_probes_table_values,
+ dtrace_enable_probe,
+ dtrace_disable_probe
+};
+
+/* Implementation of the `info probes dtrace' command. */
+
+static void
+info_probes_dtrace_command (char *arg, int from_tty)
+{
+ info_probes_for_ops (arg, from_tty, &dtrace_probe_ops);
+}
+
+void _initialize_dtrace_probe (void);
+
+void
+_initialize_dtrace_probe (void)
+{
+ VEC_safe_push (probe_ops_cp, all_probe_ops, &dtrace_probe_ops);
+
+ add_cmd ("dtrace", class_info, info_probes_dtrace_command,
+ _("\
+Show information about DTrace static probes.\n\
+Usage: info probes dtrace [PROVIDER [NAME [OBJECT]]]\n\
+Each argument is a regular expression, used to select probes.\n\
+PROVIDER matches probe provider names.\n\
+NAME matches the probe names.\n\
+OBJECT matches the executable or shared library name."),
+ info_probes_cmdlist_get ());
+}
--
1.7.10.4