drgn/libdrgn/linux_kernel.h
Omar Sandoval 0e3054a0ba libdrgn: make addresses wrap around when reading memory
Define that addresses for memory reads wrap around after the maximum
address rather than the current unpredictable behavior. This is done by:

1. Reworking drgn_memory_reader to work with an inclusive address range
   so that a segment can contain UINT64_MAX. drgn_memory_reader remains
   agnostic to the maximum address and requires that address ranges do
   not overflow a uint64_t.
2. Adding the overflow/wrap-around logic to
   drgn_program_add_memory_segment() and drgn_program_read_memory().
3. Changing direct uses of drgn_memory_reader_reader() to
   drgn_program_read_memory() now that they are no longer equivalent.

(For some platforms, a fault might be more appropriate than wrapping
around, but this is a step in the right direction.)

Signed-off-by: Omar Sandoval <osandov@osandov.com>
2021-06-03 17:49:29 -07:00

48 lines
1.4 KiB
C

// Copyright (c) Facebook, Inc. and its affiliates.
// SPDX-License-Identifier: GPL-3.0-or-later
#ifndef DRGN_LINUX_KERNEL_H
#define DRGN_LINUX_KERNEL_H
#include "drgn.h"
struct drgn_debug_info_load_state;
struct vmcoreinfo;
struct drgn_error *read_memory_via_pgtable(void *buf, uint64_t address,
size_t count, uint64_t offset,
void *arg, bool physical);
struct drgn_error *parse_vmcoreinfo(const char *desc, size_t descsz,
struct vmcoreinfo *ret);
struct drgn_error *proc_kallsyms_symbol_addr(const char *name,
unsigned long *ret);
struct drgn_error *read_vmcoreinfo_fallback(struct drgn_program *prog);
struct drgn_error *linux_kernel_object_find(const char *name, size_t name_len,
const char *filename,
enum drgn_find_object_flags flags,
void *arg, struct drgn_object *ret);
struct drgn_error *
linux_kernel_report_debug_info(struct drgn_debug_info_load_state *load);
#define KDUMP_SIGNATURE "KDUMP "
#define KDUMP_SIG_LEN (sizeof(KDUMP_SIGNATURE) - 1)
#ifdef WITH_LIBKDUMPFILE
struct drgn_error *drgn_program_cache_prstatus_kdump(struct drgn_program *prog);
struct drgn_error *drgn_program_set_kdump(struct drgn_program *prog);
#else
static inline struct drgn_error *
drgn_program_set_kdump(struct drgn_program *prog)
{
return drgn_error_create(DRGN_ERROR_INVALID_ARGUMENT,
"drgn was built without libkdumpfile support");
}
#endif
#endif /* DRGN_LINUX_KERNEL_H */