| /* DTrace probe support for GDB. |
| |
| Copyright (C) 2014-2023 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 "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" |
| #include "expop.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 |
| |
| /* The following structure represents a single argument for the |
| probe. */ |
| |
| struct dtrace_probe_arg |
| { |
| dtrace_probe_arg (struct type *type_, std::string &&type_str_, |
| expression_up &&expr_) |
| : type (type_), type_str (std::move (type_str_)), |
| expr (std::move (expr_)) |
| {} |
| |
| /* The type of the probe argument. */ |
| struct type *type; |
| |
| /* A string describing the type. */ |
| std::string type_str; |
| |
| /* The argument converted to an internal GDB expression. */ |
| expression_up expr; |
| }; |
| |
| /* 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; |
| }; |
| |
| /* Class that implements the static probe methods for "stap" probes. */ |
| |
| class dtrace_static_probe_ops : public static_probe_ops |
| { |
| public: |
| /* See probe.h. */ |
| bool is_linespec (const char **linespecp) const override; |
| |
| /* See probe.h. */ |
| void get_probes (std::vector<std::unique_ptr<probe>> *probesp, |
| struct objfile *objfile) const override; |
| |
| /* See probe.h. */ |
| const char *type_name () const override; |
| |
| /* See probe.h. */ |
| bool can_enable () const override |
| { |
| return true; |
| } |
| |
| /* See probe.h. */ |
| std::vector<struct info_probe_column> gen_info_probes_table_header |
| () const override; |
| }; |
| |
| /* DTrace static_probe_ops. */ |
| |
| const dtrace_static_probe_ops dtrace_static_probe_ops {}; |
| |
| /* The following structure represents a dtrace probe. */ |
| |
| class dtrace_probe : public probe |
| { |
| public: |
| /* Constructor for dtrace_probe. */ |
| dtrace_probe (std::string &&name_, std::string &&provider_, CORE_ADDR address_, |
| struct gdbarch *arch_, |
| std::vector<struct dtrace_probe_arg> &&args_, |
| std::vector<struct dtrace_probe_enabler> &&enablers_) |
| : probe (std::move (name_), std::move (provider_), address_, arch_), |
| m_args (std::move (args_)), |
| m_enablers (std::move (enablers_)), |
| m_args_expr_built (false) |
| {} |
| |
| /* See probe.h. */ |
| CORE_ADDR get_relocated_address (struct objfile *objfile) override; |
| |
| /* See probe.h. */ |
| unsigned get_argument_count (struct gdbarch *gdbarch) override; |
| |
| /* See probe.h. */ |
| bool can_evaluate_arguments () const override; |
| |
| /* See probe.h. */ |
| struct value *evaluate_argument (unsigned n, |
| frame_info_ptr frame) override; |
| |
| /* See probe.h. */ |
| void compile_to_ax (struct agent_expr *aexpr, |
| struct axs_value *axs_value, |
| unsigned n) override; |
| |
| /* See probe.h. */ |
| const static_probe_ops *get_static_ops () const override; |
| |
| /* See probe.h. */ |
| std::vector<const char *> gen_info_probes_table_values () const override; |
| |
| /* See probe.h. */ |
| void enable () override; |
| |
| /* See probe.h. */ |
| void disable () override; |
| |
| /* Return the Nth argument of the probe. */ |
| struct dtrace_probe_arg *get_arg_by_number (unsigned n, |
| struct gdbarch *gdbarch); |
| |
| /* Build the GDB internal expression that, once evaluated, will |
| calculate the values of the arguments of the probe. */ |
| void build_arg_exprs (struct gdbarch *gdbarch); |
| |
| /* Determine whether the probe is "enabled" or "disabled". A |
| disabled probe is a probe in which one or more enablers are |
| disabled. */ |
| bool is_enabled () const; |
| |
| private: |
| /* A probe can have zero or more arguments. */ |
| std::vector<struct dtrace_probe_arg> m_args; |
| |
| /* A probe can have zero or more "enablers" associated with it. */ |
| std::vector<struct dtrace_probe_enabler> m_enablers; |
| |
| /* Whether the expressions for the arguments have been built. */ |
| bool m_args_expr_built; |
| }; |
| |
| /* 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 |
| { |
| /* Null section. */ |
| DTRACE_DOF_SECT_TYPE_NONE = 0, |
| /* A dof_ecbdesc_t. */ |
| DTRACE_DOF_SECT_TYPE_ECBDESC = 3, |
| /* A string table. */ |
| DTRACE_DOF_SECT_TYPE_STRTAB = 8, |
| /* A dof_provider_t */ |
| DTRACE_DOF_SECT_TYPE_PROVIDER = 15, |
| /* Array of dof_probe_t */ |
| DTRACE_DOF_SECT_TYPE_PROBES = 16, |
| /* An array of probe arg mappings. */ |
| DTRACE_DOF_SECT_TYPE_PRARGS = 17, |
| /* An array of probe arg offsets. */ |
| DTRACE_DOF_SECT_TYPE_PROFFS = 18, |
| /* An array of probe is-enabled offsets. */ |
| 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. */ |
| |
| /* Offsets to index the dofh_ident[] array defined below. */ |
| |
| enum dtrace_dof_ident |
| { |
| /* First byte of the magic number. */ |
| DTRACE_DOF_ID_MAG0 = 0, |
| /* Second byte of the magic number. */ |
| DTRACE_DOF_ID_MAG1 = 1, |
| /* Third byte of the magic number. */ |
| DTRACE_DOF_ID_MAG2 = 2, |
| /* Fourth byte of the magic number. */ |
| DTRACE_DOF_ID_MAG3 = 3, |
| /* An enum_dof_encoding value. */ |
| DTRACE_DOF_ID_ENCODING = 5 |
| }; |
| |
| /* Possible values for dofh_ident[DOF_ID_ENCODING]. */ |
| |
| enum dtrace_dof_encoding |
| { |
| /* The DOF program is little-endian. */ |
| DTRACE_DOF_ENCODE_LSB = 1, |
| /* The DOF program is big-endian. */ |
| DTRACE_DOF_ENCODE_MSB = 2 |
| }; |
| |
| /* A DOF header, which describes the contents of a DOF program: number |
| of sections, size, etc. */ |
| |
| struct dtrace_dof_hdr |
| { |
| /* Identification bytes (see above). */ |
| uint8_t dofh_ident[16]; |
| /* File attribute flags (if any). */ |
| uint32_t dofh_flags; |
| /* Size of file header in bytes. */ |
| uint32_t dofh_hdrsize; |
| /* Size of section header in bytes. */ |
| uint32_t dofh_secsize; |
| /* Number of section headers. */ |
| uint32_t dofh_secnum; |
| /* File offset of section headers. */ |
| uint64_t dofh_secoff; |
| /* File size of loadable portion. */ |
| uint64_t dofh_loadsz; |
| /* File size of entire DOF file. */ |
| uint64_t dofh_filesz; |
| /* Reserved for future use. */ |
| uint64_t dofh_pad; |
| }; |
| |
| /* A DOF section, whose contents depend on its type. The several |
| supported section types are described in the enum |
| dtrace_dof_sect_type above. */ |
| |
| struct dtrace_dof_sect |
| { |
| /* Section type (see the define above). */ |
| uint32_t dofs_type; |
| /* Section data memory alignment. */ |
| uint32_t dofs_align; |
| /* Section flags (if any). */ |
| uint32_t dofs_flags; |
| /* Size of section entry (if table). */ |
| uint32_t dofs_entsize; |
| /* DOF + offset points to the section data. */ |
| uint64_t dofs_offset; |
| /* Size of section data in bytes. */ |
| uint64_t dofs_size; |
| }; |
| |
| /* A DOF provider, which is the provider of a probe. */ |
| |
| struct dtrace_dof_provider |
| { |
| /* Link to a DTRACE_DOF_SECT_TYPE_STRTAB section. */ |
| uint32_t dofpv_strtab; |
| /* Link to a DTRACE_DOF_SECT_TYPE_PROBES section. */ |
| uint32_t dofpv_probes; |
| /* Link to a DTRACE_DOF_SECT_TYPE_PRARGS section. */ |
| uint32_t dofpv_prargs; |
| /* Link to a DTRACE_DOF_SECT_TYPE_PROFFS section. */ |
| uint32_t dofpv_proffs; |
| /* Provider name string. */ |
| uint32_t dofpv_name; |
| /* Provider attributes. */ |
| uint32_t dofpv_provattr; |
| /* Module attributes. */ |
| uint32_t dofpv_modattr; |
| /* Function attributes. */ |
| uint32_t dofpv_funcattr; |
| /* Name attributes. */ |
| uint32_t dofpv_nameattr; |
| /* Args attributes. */ |
| uint32_t dofpv_argsattr; |
| /* Link to a DTRACE_DOF_SECT_PRENOFFS section. */ |
| uint32_t dofpv_prenoffs; |
| }; |
| |
| /* A set of DOF probes and is-enabled probes sharing a base address |
| and several attributes. The particular locations and attributes of |
| each probe are maintained in arrays in several other DOF sections. |
| See the comment in dtrace_process_dof_probe for details on how |
| these attributes are stored. */ |
| |
| struct dtrace_dof_probe |
| { |
| /* Probe base address or offset. */ |
| uint64_t dofpr_addr; |
| /* Probe function string. */ |
| uint32_t dofpr_func; |
| /* Probe name string. */ |
| uint32_t dofpr_name; |
| /* Native argument type strings. */ |
| uint32_t dofpr_nargv; |
| /* Translated argument type strings. */ |
| uint32_t dofpr_xargv; |
| /* Index of first argument mapping. */ |
| uint32_t dofpr_argidx; |
| /* Index of first offset entry. */ |
| uint32_t dofpr_offidx; |
| /* Native argument count. */ |
| uint8_t dofpr_nargc; |
| /* Translated argument count. */ |
| uint8_t dofpr_xargc; |
| /* Number of offset entries for probe. */ |
| uint16_t dofpr_noffs; |
| /* Index of first is-enabled offset. */ |
| uint32_t dofpr_enoffidx; |
| /* Number of is-enabled offsets. */ |
| uint16_t dofpr_nenoffs; |
| /* Reserved for future use. */ |
| uint16_t dofpr_pad1; |
| /* Reserved for future use. */ |
| 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 function to examine the probe described by the given PROBE |
| and PROVIDER data structures and add it to the PROBESP vector. |
| STRTAB, OFFTAB, EOFFTAB and ARGTAB are pointers to tables in the |
| DOF program containing the attributes for the probe. */ |
| |
| static void |
| dtrace_process_dof_probe (struct objfile *objfile, |
| struct gdbarch *gdbarch, |
| std::vector<std::unique_ptr<probe>> *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) |
| { |
| int i, j, num_probes, num_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. */ |
| std::vector<struct dtrace_probe_enabler> enablers; |
| 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); |
| enablers.push_back (enabler); |
| } |
| |
| for (i = 0; i < num_probes; i++) |
| { |
| uint32_t probe_offset |
| = ((uint32_t *) offtab)[DOF_UINT (dof, probe->dofpr_offidx) + i]; |
| |
| /* Set the provider and the name of the probe. */ |
| const char *probe_provider |
| = strtab + DOF_UINT (dof, provider->dofpv_name); |
| const char *name = strtab + DOF_UINT (dof, probe->dofpr_name); |
| |
| /* The probe address. */ |
| CORE_ADDR address |
| = DOF_UINT (dof, probe->dofpr_addr) + DOF_UINT (dof, probe_offset); |
| |
| /* Number of arguments in the probe. */ |
| int 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'. */ |
| std::vector<struct dtrace_probe_arg> args; |
| p = strtab + DOF_UINT (dof, probe->dofpr_nargv); |
| for (j = 0; j < probe_argc; j++) |
| { |
| expression_up expr; |
| |
| /* Set arg.expr to ensure all fields in expr are initialized and |
| the compiler will not warn when arg is used. */ |
| std::string type_str (p); |
| |
| /* Use strtab_size as a sentinel. */ |
| while (*p++ != '\0' && p - strtab < strtab_size) |
| ; |
| |
| /* Try to parse a type expression from the type string. If |
| this does not work then we set the type to `long |
| int'. */ |
| struct type *type = builtin_type (gdbarch)->builtin_long; |
| |
| try |
| { |
| expr = parse_expression_with_language (type_str.c_str (), |
| language_c); |
| } |
| catch (const gdb_exception_error &ex) |
| { |
| } |
| |
| if (expr != NULL && expr->first_opcode () == OP_TYPE) |
| type = expr->evaluate_type ()->type (); |
| |
| args.emplace_back (type, std::move (type_str), std::move (expr)); |
| } |
| |
| std::vector<struct dtrace_probe_enabler> enablers_copy = enablers; |
| dtrace_probe *ret = new dtrace_probe (std::string (name), |
| std::string (probe_provider), |
| address, gdbarch, |
| std::move (args), |
| std::move (enablers_copy)); |
| |
| /* Successfully created probe. */ |
| probesp->emplace_back (ret); |
| } |
| } |
| |
| /* Helper function to collect the probes described in the DOF program |
| whose header is pointed by DOF and add them to the PROBESP vector. |
| SECT is the ELF section containing the DOF program and OBJFILE is |
| its containing object file. */ |
| |
| static void |
| dtrace_process_dof (asection *sect, struct objfile *objfile, |
| std::vector<std::unique_ptr<probe>> *probesp, |
| struct dtrace_dof_hdr *dof) |
| { |
| struct gdbarch *gdbarch = objfile->arch (); |
| 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 the encoding mark is either DTRACE_DOF_ENCODE_LSB or |
| DTRACE_DOF_ENCODE_MSB. */ |
| if (dof->dofh_ident[DTRACE_DOF_ID_ENCODING] != DTRACE_DOF_ENCODE_LSB |
| && dof->dofh_ident[DTRACE_DOF_ID_ENCODING] != DTRACE_DOF_ENCODE_MSB) |
| 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; |
| |
| if (DOF_UINT (dof, section->dofs_size) |
| < sizeof (struct dtrace_dof_provider)) |
| { |
| /* The section is smaller than expected, so do not use it. |
| This has been observed on x86-solaris 10. */ |
| goto invalid_dof_data; |
| } |
| |
| /* 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 (_("skipping section '%s' which does not contain valid DOF data."), |
| sect->name); |
| } |
| |
| /* Implementation of 'build_arg_exprs' method. */ |
| |
| void |
| dtrace_probe::build_arg_exprs (struct gdbarch *gdbarch) |
| { |
| size_t argc = 0; |
| m_args_expr_built = true; |
| |
| /* 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 (dtrace_probe_arg &arg : m_args) |
| { |
| /* Initialize the expression builder. The language does not |
| matter, since we are using our own parser. */ |
| expr_builder builder (current_language, gdbarch); |
| |
| /* The argument value, which is ABI dependent and casted to |
| `long int'. */ |
| expr::operation_up op = gdbarch_dtrace_parse_probe_argument (gdbarch, |
| argc); |
| |
| /* 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 != NULL) |
| op = expr::make_operation<expr::unop_cast_operation> (std::move (op), |
| arg.type); |
| |
| builder.set_operation (std::move (op)); |
| arg.expr = builder.release (); |
| ++argc; |
| } |
| } |
| |
| /* Implementation of 'get_arg_by_number' method. */ |
| |
| struct dtrace_probe_arg * |
| dtrace_probe::get_arg_by_number (unsigned n, struct gdbarch *gdbarch) |
| { |
| if (!m_args_expr_built) |
| this->build_arg_exprs (gdbarch); |
| |
| if (n > m_args.size ()) |
| internal_error (_("Probe '%s' has %d arguments, but GDB is requesting\n" |
| "argument %u. This should not happen. Please\n" |
| "report this bug."), |
| this->get_name ().c_str (), |
| (int) m_args.size (), n); |
| |
| return &m_args[n]; |
| } |
| |
| /* Implementation of the probe is_enabled method. */ |
| |
| bool |
| dtrace_probe::is_enabled () const |
| { |
| struct gdbarch *gdbarch = this->get_gdbarch (); |
| |
| for (const dtrace_probe_enabler &enabler : m_enablers) |
| if (!gdbarch_dtrace_probe_is_enabled (gdbarch, enabler.address)) |
| return false; |
| |
| return true; |
| } |
| |
| /* Implementation of the get_probe_address method. */ |
| |
| CORE_ADDR |
| dtrace_probe::get_relocated_address (struct objfile *objfile) |
| { |
| return this->get_address () + objfile->text_section_offset (); |
| } |
| |
| /* Implementation of the get_argument_count method. */ |
| |
| unsigned |
| dtrace_probe::get_argument_count (struct gdbarch *gdbarch) |
| { |
| return m_args.size (); |
| } |
| |
| /* Implementation of the can_evaluate_arguments method. */ |
| |
| bool |
| dtrace_probe::can_evaluate_arguments () const |
| { |
| struct gdbarch *gdbarch = this->get_gdbarch (); |
| |
| return gdbarch_dtrace_parse_probe_argument_p (gdbarch); |
| } |
| |
| /* Implementation of the evaluate_argument method. */ |
| |
| struct value * |
| dtrace_probe::evaluate_argument (unsigned n, |
| frame_info_ptr frame) |
| { |
| struct gdbarch *gdbarch = this->get_gdbarch (); |
| struct dtrace_probe_arg *arg; |
| |
| arg = this->get_arg_by_number (n, gdbarch); |
| return arg->expr->evaluate (arg->type); |
| } |
| |
| /* Implementation of the compile_to_ax method. */ |
| |
| void |
| dtrace_probe::compile_to_ax (struct agent_expr *expr, struct axs_value *value, |
| unsigned n) |
| { |
| struct dtrace_probe_arg *arg; |
| |
| arg = this->get_arg_by_number (n, expr->gdbarch); |
| arg->expr->op->generate_ax (arg->expr.get (), expr, value); |
| |
| require_rvalue (expr, value); |
| value->type = arg->type; |
| } |
| |
| /* Implementation of the 'get_static_ops' method. */ |
| |
| const static_probe_ops * |
| dtrace_probe::get_static_ops () const |
| { |
| return &dtrace_static_probe_ops; |
| } |
| |
| /* Implementation of the gen_info_probes_table_values method. */ |
| |
| std::vector<const char *> |
| dtrace_probe::gen_info_probes_table_values () const |
| { |
| const char *val = NULL; |
| |
| if (m_enablers.empty ()) |
| val = "always"; |
| else if (!gdbarch_dtrace_probe_is_enabled_p (this->get_gdbarch ())) |
| val = "unknown"; |
| else if (this->is_enabled ()) |
| val = "yes"; |
| else |
| val = "no"; |
| |
| return std::vector<const char *> { val }; |
| } |
| |
| /* Implementation of the enable method. */ |
| |
| void |
| dtrace_probe::enable () |
| { |
| struct gdbarch *gdbarch = this->get_gdbarch (); |
| |
| /* Enabling a dtrace probe implies patching the text section of the |
| running process, so make sure the inferior is indeed running. */ |
| if (inferior_ptid == null_ptid) |
| error (_("No inferior running")); |
| |
| /* Fast path. */ |
| if (this->is_enabled ()) |
| return; |
| |
| /* Iterate over all defined enabler in the given probe and enable |
| them all using the corresponding gdbarch hook. */ |
| for (const dtrace_probe_enabler &enabler : m_enablers) |
| if (gdbarch_dtrace_enable_probe_p (gdbarch)) |
| gdbarch_dtrace_enable_probe (gdbarch, enabler.address); |
| } |
| |
| |
| /* Implementation of the disable_probe method. */ |
| |
| void |
| dtrace_probe::disable () |
| { |
| struct gdbarch *gdbarch = this->get_gdbarch (); |
| |
| /* Disabling a dtrace probe implies patching the text section of the |
| running process, so make sure the inferior is indeed running. */ |
| if (inferior_ptid == null_ptid) |
| error (_("No inferior running")); |
| |
| /* Fast path. */ |
| if (!this->is_enabled ()) |
| return; |
| |
| /* Are we trying to disable a probe that does not have any enabler |
| associated? */ |
| if (m_enablers.empty ()) |
| error (_("Probe %s:%s cannot be disabled: no enablers."), |
| this->get_provider ().c_str (), this->get_name ().c_str ()); |
| |
| /* Iterate over all defined enabler in the given probe and disable |
| them all using the corresponding gdbarch hook. */ |
| for (dtrace_probe_enabler &enabler : m_enablers) |
| if (gdbarch_dtrace_disable_probe_p (gdbarch)) |
| gdbarch_dtrace_disable_probe (gdbarch, enabler.address); |
| } |
| |
| /* Implementation of the is_linespec method. */ |
| |
| bool |
| dtrace_static_probe_ops::is_linespec (const char **linespecp) const |
| { |
| static const char *const keywords[] = { "-pdtrace", "-probe-dtrace", NULL }; |
| |
| return probe_is_linespec_by_keyword (linespecp, keywords); |
| } |
| |
| /* Implementation of the get_probes method. */ |
| |
| void |
| dtrace_static_probe_ops::get_probes |
| (std::vector<std::unique_ptr<probe>> *probesp, |
| struct objfile *objfile) const |
| { |
| bfd *abfd = objfile->obfd.get (); |
| 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) |
| { |
| bfd_byte *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, &dof) && dof != NULL) |
| dtrace_process_dof (sect, objfile, probesp, |
| (struct dtrace_dof_hdr *) dof); |
| else |
| complaint (_("could not obtain the contents of" |
| "section '%s' in objfile `%s'."), |
| bfd_section_name (sect), bfd_get_filename (abfd)); |
| |
| xfree (dof); |
| } |
| } |
| } |
| |
| /* Implementation of the type_name method. */ |
| |
| const char * |
| dtrace_static_probe_ops::type_name () const |
| { |
| return "dtrace"; |
| } |
| |
| /* Implementation of the gen_info_probes_table_header method. */ |
| |
| std::vector<struct info_probe_column> |
| dtrace_static_probe_ops::gen_info_probes_table_header () const |
| { |
| struct info_probe_column dtrace_probe_column; |
| |
| dtrace_probe_column.field_name = "enabled"; |
| dtrace_probe_column.print_name = _("Enabled"); |
| |
| return std::vector<struct info_probe_column> { dtrace_probe_column }; |
| } |
| |
| /* Implementation of the `info probes dtrace' command. */ |
| |
| static void |
| info_probes_dtrace_command (const char *arg, int from_tty) |
| { |
| info_probes_for_spops (arg, from_tty, &dtrace_static_probe_ops); |
| } |
| |
| void _initialize_dtrace_probe (); |
| void |
| _initialize_dtrace_probe () |
| { |
| all_static_probe_ops.push_back (&dtrace_static_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 ()); |
| } |