drgn/libdrgn/program.h
Omar Sandoval a5cd92f24e libdrgn: make vmcoreinfo accessible before loading debug info
UTS_RELEASE is currently only accessible once debug info is loaded with
prog.load_debug_info(main=True). This makes it difficult to get the
release, find the appropriate vmlinux, then load the found vmlinux. We
can add vmcoreinfo_object_find as part of set_core_dump(), which makes
it possible to do the following:

  prog = drgn.Program()
  prog.set_core_dump(core_dump_path)
  release = prog['UTS_RELEASE'].string_()
  vmlinux_path = find_vmlinux(release)
  prog.load_debug_info([vmlinux_path])

The only downside is that this ends up using the default definition of
char rather than what we would get from the debug info, but that
shouldn't be a big problem.
2020-02-19 12:11:45 -08:00

175 lines
4.4 KiB
C

// Copyright 2018-2019 - Omar Sandoval
// SPDX-License-Identifier: GPL-3.0+
/**
* @file
*
* Program internals.
*
* See @ref ProgramInternals.
*/
#ifndef DRGN_PROGRAM_H
#define DRGN_PROGRAM_H
#include <elfutils/libdwfl.h>
#ifdef WITH_LIBKDUMPFILE
#include <libkdumpfile/kdumpfile.h>
#endif
#include "hash_table.h"
#include "memory_reader.h"
#include "object_index.h"
#include "platform.h"
#include "type_index.h"
/**
* @ingroup Internals
*
* @defgroup ProgramInternals Programs
*
* Program internals.
*
* @{
*/
/** The important parts of the VMCOREINFO note of a Linux kernel core. */
struct vmcoreinfo {
/** <tt>uname -r</tt> */
char osrelease[128];
/** PAGE_SIZE of the kernel. */
uint64_t page_size;
/**
* The offset from the compiled address of the kernel image to its
* actual address in memory.
*
* This is non-zero if kernel address space layout randomization (KASLR)
* is enabled.
*/
uint64_t kaslr_offset;
};
DEFINE_HASH_MAP_TYPE(drgn_prstatus_map, uint32_t, struct string)
struct drgn_dwarf_info_cache;
struct drgn_dwarf_index;
struct drgn_program {
/** @privatesection */
struct drgn_memory_reader reader;
struct drgn_type_index tindex;
struct drgn_object_index oindex;
struct drgn_memory_file_segment *file_segments;
size_t num_file_segments;
/*
* Valid iff <tt>flags & DRGN_PROGRAM_IS_LINUX_KERNEL</tt>.
*/
struct vmcoreinfo vmcoreinfo;
#ifdef WITH_LIBKDUMPFILE
kdump_ctx_t *kdump_ctx;
#endif
/*
* Valid iff <tt>!(flags & DRGN_PROGRAM_IS_LIVE)</tt>, unless the file
* was a kdump file.
*/
Elf *core;
int core_fd;
/*
* Valid iff
* <tt>(flags & (DRGN_PROGRAM_IS_LINUX_KERNEL | DRGN_PROGRAM_IS_LIVE)) ==
* DRGN_PROGRAM_IS_LIVE</tt>.
*/
pid_t pid;
struct drgn_dwarf_info_cache *_dicache;
struct drgn_prstatus_map prstatus_cache;
/* See @ref drgn_object_stack_trace(). */
struct drgn_error *stack_trace_err;
/* See @ref drgn_object_stack_trace_next_thread(). */
const struct drgn_object *stack_trace_obj;
uint32_t stack_trace_tid;
enum drgn_program_flags flags;
struct drgn_platform platform;
bool has_platform;
bool attached_dwfl_state;
bool prstatus_cached;
/* Cache for @ref linux_helper_task_state_to_char(). */
char *task_state_chars;
uint64_t task_report;
};
/** Initialize a @ref drgn_program. */
void drgn_program_init(struct drgn_program *prog,
const struct drgn_platform *platform);
/** Deinitialize a @ref drgn_program. */
void drgn_program_deinit(struct drgn_program *prog);
/**
* Set the @ref drgn_platform of a @ref drgn_program if it hasn't been set
* yet.
*/
void drgn_program_set_platform(struct drgn_program *prog,
const struct drgn_platform *platform);
/**
* Implement @ref drgn_program_from_core_dump() on an initialized @ref
* drgn_program.
*/
struct drgn_error *drgn_program_init_core_dump(struct drgn_program *prog,
const char *path);
/**
* Implement @ref drgn_program_from_kernel() on an initialized @ref
* drgn_program.
*/
struct drgn_error *drgn_program_init_kernel(struct drgn_program *prog);
/**
* Implement @ref drgn_program_from_pid() on an initialized @ref drgn_program.
*/
struct drgn_error *drgn_program_init_pid(struct drgn_program *prog, pid_t pid);
static inline bool drgn_program_is_little_endian(struct drgn_program *prog)
{
assert(prog->has_platform);
return prog->platform.flags & DRGN_PLATFORM_IS_LITTLE_ENDIAN;
}
static inline bool drgn_program_is_64_bit(struct drgn_program *prog)
{
assert(prog->has_platform);
return prog->platform.flags & DRGN_PLATFORM_IS_64_BIT;
}
struct drgn_error *drgn_program_get_dwfl(struct drgn_program *prog, Dwfl **ret);
/**
* Find the @c NT_PRSTATUS note for the given thread ID.
*
* This assumes that <tt>prog->core</tt> is not @c NULL.
*
* @param[out] ret Returned note data. If not found, <tt>ret->str</tt> is set to
* @c NULL and <tt>ret->len</tt> is set to zero.
*/
struct drgn_error *drgn_program_find_prstatus(struct drgn_program *prog,
uint32_t tid, struct string *ret);
/*
* Like @ref drgn_program_find_symbol_by_address(), but @p ret is already
* allocated, we may already know the module, and doesn't return a @ref
* drgn_error.
*
* @param[in] module Module containing the address. May be @c NULL, in which
* case this will look it up.
* @return Whether the symbol was found.
*/
bool drgn_program_find_symbol_by_address_internal(struct drgn_program *prog,
uint64_t address,
Dwfl_Module *module,
struct drgn_symbol *ret);
/** @} */
#endif /* DRGN_PROGRAM_H */