source: mainline/uspace/app/taskdump/elf_core.c@ 9af1c61

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 9af1c61 was 8e3498b, checked in by Jiri Svoboda <jiri@…>, 8 years ago

vfs_read/write() should return error code separately from number of bytes transferred.
  • Property mode set to 100644
File size: 8.4 KB
Line 
1/*
2 * Copyright (c) 2011 Jiri Svoboda
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup taskdump
30 * @{
31 */
32/** @file Write ELF core files.
33 *
34 * Creates ELF core files. Core files do not seem to be specified by some
35 * standard (the System V ABI explicitely states that it does not specify
36 * them).
37 *
38 * Looking at core files produced by Linux, these don't have section headers,
39 * only program headers, although objdump shows them as having sections.
40 * Basically at the beginning there should be a note segment followed
41 * by one loadable segment per memory area.
42 *
43 * The note segment contains a series of records with register state,
44 * process info etc. We only write one record NT_PRSTATUS which contains
45 * process/register state (anything which is not register state we fill
46 * with zeroes).
47 */
48
49#include <align.h>
50#include <elf/elf.h>
51#include <elf/elf_linux.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <stdint.h>
55#include <stddef.h>
56#include <errno.h>
57#include <mem.h>
58#include <as.h>
59#include <udebug.h>
60#include <macros.h>
61#include <libarch/istate.h>
62#include <vfs/vfs.h>
63
64#include "elf_core.h"
65
66static off64_t align_foff_up(off64_t, uintptr_t, size_t);
67static int write_mem_area(int, aoff64_t *, as_area_info_t *, async_sess_t *);
68
69#define BUFFER_SIZE 0x1000
70static uint8_t buffer[BUFFER_SIZE];
71
72/** Save ELF core file.
73 *
74 * @param file_name Name of file to save to.
75 * @param ainfo Array of @a n memory area info structures.
76 * @param n Number of memory areas.
77 * @param sess Debugging session.
78 *
79 * @return EOK on sucess.
80 * @return ENOENT if file cannot be created.
81 * @return ENOMEM on out of memory.
82 * @return EIO on write error.
83 *
84 */
85int elf_core_save(const char *file_name, as_area_info_t *ainfo, unsigned int n,
86 async_sess_t *sess, istate_t *istate)
87{
88 elf_header_t elf_hdr;
89 off64_t foff;
90 size_t n_ph;
91 elf_word flags;
92 elf_segment_header_t *p_hdr;
93 elf_prstatus_t pr_status;
94 elf_note_t note;
95 size_t word_size;
96 aoff64_t pos = 0;
97
98 int fd;
99 int rc;
100 size_t nwr;
101 unsigned int i;
102
103#ifdef __32_BITS__
104 word_size = 4;
105#endif
106#ifdef __64_BITS__
107 /*
108 * This should be 8 per the 64-bit ELF spec, but the Linux kernel
109 * screws up and uses 4 anyway (and screws up elf_note_t as well)
110 * and we are trying to be compatible with Linux GDB target. Sigh.
111 */
112 word_size = 4;
113#endif
114 memset(&pr_status, 0, sizeof(pr_status));
115 istate_to_elf_regs(istate, &pr_status.regs);
116
117 n_ph = n + 1;
118
119 p_hdr = malloc(sizeof(elf_segment_header_t) * n_ph);
120 if (p_hdr == NULL) {
121 printf("Failed allocating memory.\n");
122 return ENOMEM;
123 }
124
125 fd = vfs_lookup_open(file_name, WALK_REGULAR | WALK_MAY_CREATE,
126 MODE_WRITE);
127 if (fd < 0) {
128 printf("Failed opening file.\n");
129 free(p_hdr);
130 return ENOENT;
131 }
132
133 /*
134 * File layout:
135 *
136 * ELF header
137 * program headers
138 * note segment
139 * repeat:
140 * (pad for alignment)
141 * core segment
142 * end repeat
143 */
144
145 memset(&elf_hdr, 0, sizeof(elf_hdr));
146 elf_hdr.e_ident[EI_MAG0] = ELFMAG0;
147 elf_hdr.e_ident[EI_MAG1] = ELFMAG1;
148 elf_hdr.e_ident[EI_MAG2] = ELFMAG2;
149 elf_hdr.e_ident[EI_MAG3] = ELFMAG3;
150 elf_hdr.e_ident[EI_CLASS] = ELF_CLASS;
151 elf_hdr.e_ident[EI_DATA] = ELF_DATA_ENCODING;
152 elf_hdr.e_ident[EI_VERSION] = EV_CURRENT;
153
154 elf_hdr.e_type = ET_CORE;
155 elf_hdr.e_machine = ELF_MACHINE;
156 elf_hdr.e_version = EV_CURRENT;
157 elf_hdr.e_entry = 0;
158 elf_hdr.e_phoff = sizeof(elf_header_t);
159 elf_hdr.e_shoff = 0;
160 elf_hdr.e_flags = 0;
161 elf_hdr.e_ehsize = sizeof(elf_hdr);
162 elf_hdr.e_phentsize = sizeof(elf_segment_header_t);
163 elf_hdr.e_phnum = n_ph;
164 elf_hdr.e_shentsize = 0;
165 elf_hdr.e_shnum = 0;
166 elf_hdr.e_shstrndx = 0;
167
168 /* foff is used for allocation of file space for segment data. */
169 foff = elf_hdr.e_phoff + n_ph * sizeof(elf_segment_header_t);
170
171 memset(&p_hdr[0], 0, sizeof(p_hdr[0]));
172 p_hdr[0].p_type = PT_NOTE;
173 p_hdr[0].p_offset = foff;
174 p_hdr[0].p_vaddr = 0;
175 p_hdr[0].p_paddr = 0;
176 p_hdr[0].p_filesz = sizeof(elf_note_t)
177 + ALIGN_UP((str_size("CORE") + 1), word_size)
178 + ALIGN_UP(sizeof(elf_prstatus_t), word_size);
179 p_hdr[0].p_memsz = 0;
180 p_hdr[0].p_flags = 0;
181 p_hdr[0].p_align = 1;
182
183 foff += p_hdr[0].p_filesz;
184
185 for (i = 0; i < n; ++i) {
186 foff = align_foff_up(foff, ainfo[i].start_addr, PAGE_SIZE);
187
188 flags = 0;
189 if (ainfo[i].flags & AS_AREA_READ)
190 flags |= PF_R;
191 if (ainfo[i].flags & AS_AREA_WRITE)
192 flags |= PF_W;
193 if (ainfo[i].flags & AS_AREA_EXEC)
194 flags |= PF_X;
195
196 memset(&p_hdr[i + 1], 0, sizeof(p_hdr[i + 1]));
197 p_hdr[i + 1].p_type = PT_LOAD;
198 p_hdr[i + 1].p_offset = foff;
199 p_hdr[i + 1].p_vaddr = ainfo[i].start_addr;
200 p_hdr[i + 1].p_paddr = 0;
201 p_hdr[i + 1].p_filesz = ainfo[i].size;
202 p_hdr[i + 1].p_memsz = ainfo[i].size;
203 p_hdr[i + 1].p_flags = flags;
204 p_hdr[i + 1].p_align = PAGE_SIZE;
205
206 foff += ainfo[i].size;
207 }
208
209 rc = vfs_write(fd, &pos, &elf_hdr, sizeof(elf_hdr), &nwr);
210 if (rc != EOK) {
211 printf("Failed writing ELF header.\n");
212 free(p_hdr);
213 return EIO;
214 }
215
216 for (i = 0; i < n_ph; ++i) {
217 rc = vfs_write(fd, &pos, &p_hdr[i], sizeof(p_hdr[i]), &nwr);
218 if (rc != EOK) {
219 printf("Failed writing program header.\n");
220 free(p_hdr);
221 return EIO;
222 }
223 }
224
225 pos = p_hdr[0].p_offset;
226
227 /*
228 * Write note header
229 */
230 note.namesz = str_size("CORE") + 1;
231 note.descsz = sizeof(elf_prstatus_t);
232 note.type = NT_PRSTATUS;
233
234 rc = vfs_write(fd, &pos, &note, sizeof(elf_note_t), &nwr);
235 if (rc != EOK) {
236 printf("Failed writing note header.\n");
237 free(p_hdr);
238 return EIO;
239 }
240
241 rc = vfs_write(fd, &pos, "CORE", note.namesz, &nwr);
242 if (rc != EOK) {
243 printf("Failed writing note header.\n");
244 free(p_hdr);
245 return EIO;
246 }
247
248 pos = ALIGN_UP(pos, word_size);
249
250 rc = vfs_write(fd, &pos, &pr_status, sizeof(elf_prstatus_t), &nwr);
251 if (rc != EOK) {
252 printf("Failed writing register data.\n");
253 free(p_hdr);
254 return EIO;
255 }
256
257 for (i = 1; i < n_ph; ++i) {
258 pos = p_hdr[i].p_offset;
259 if (write_mem_area(fd, &pos, &ainfo[i - 1], sess) != EOK) {
260 printf("Failed writing memory data.\n");
261 free(p_hdr);
262 return EIO;
263 }
264 }
265
266 free(p_hdr);
267
268 return EOK;
269}
270
271/** Align file offset up to be congruent with vaddr modulo page size. */
272static off64_t align_foff_up(off64_t foff, uintptr_t vaddr, size_t page_size)
273{
274 off64_t rva = vaddr % page_size;
275 off64_t rfo = foff % page_size;
276
277 if (rva >= rfo)
278 return (foff + (rva - rfo));
279
280 return (foff + (page_size + (rva - rfo)));
281}
282
283/** Write memory area from application to core file.
284 *
285 * @param fd File to write to.
286 * @param pos Pointer to the position to write to.
287 * @param area Memory area info structure.
288 * @param sess Debugging session.
289 *
290 * @return EOK on success, EIO on failure.
291 *
292 */
293static int write_mem_area(int fd, aoff64_t *pos, as_area_info_t *area,
294 async_sess_t *sess)
295{
296 size_t to_copy;
297 size_t total;
298 uintptr_t addr;
299 int rc;
300 size_t nwr;
301
302 addr = area->start_addr;
303 total = 0;
304
305 while (total < area->size) {
306 to_copy = min(area->size - total, BUFFER_SIZE);
307 rc = udebug_mem_read(sess, buffer, addr, to_copy);
308 if (rc < 0) {
309 printf("Failed reading task memory.\n");
310 return EIO;
311 }
312
313 rc = vfs_write(fd, pos, buffer, to_copy, &nwr);
314 if (rc != EOK) {
315 printf("Failed writing memory contents.\n");
316 return EIO;
317 }
318
319 addr += to_copy;
320 total += to_copy;
321 }
322
323 return EOK;
324}
325
326/** @}
327 */
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