drgn/libdrgn/linux_kernel.h
Stephen Brennan 16164dbe6e libdrgn: detect flattened vmcores and raise error
The makedumpfile flattened format is occasionally seen by users, but is
not read by libkdumpfile and thus unsupported by Drgn. A simple
'reassembly' process is all that is necessary to allow Drgn to open the
vmcore, but this fact isn't easily discoverable, resulting in issues
like #344. To help users, detect this when we're testing for kdump
signatures, and raise an error with reassembly instructions.

For further details on the flattened format, consult makedumpfile(8),
particularly the sections documenting options -F and -R.

Signed-off-by: Stephen Brennan <stephen@brennan.io>
2023-08-16 09:41:26 -07:00

51 lines
1.5 KiB
C

// Copyright (c) Meta Platforms, Inc. and affiliates.
// SPDX-License-Identifier: LGPL-2.1-or-later
#ifndef DRGN_LINUX_KERNEL_H
#define DRGN_LINUX_KERNEL_H
#include "drgn.h"
struct drgn_debug_info_load_state;
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 *drgn_program_parse_vmcoreinfo(struct drgn_program *prog,
const char *desc,
size_t descsz);
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)
#define FLATTENED_SIGNATURE "makedumpfile"
#define FLATTENED_SIG_LEN (sizeof(FLATTENED_SIGNATURE) - 1)
#ifdef WITH_LIBKDUMPFILE
struct drgn_error *drgn_program_cache_kdump_notes(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 */