summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/oprofile/cell/vma_map.c
blob: f40e37316dd67b77a2ee91876882701ff446e91f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/*
 * Cell Broadband Engine OProfile Support
 *
 * (C) Copyright IBM Corporation 2006
 *
 * Author: Maynard Johnson <maynardj@us.ibm.com>
 *
 * 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
 * 2 of the License, or (at your option) any later version.
 */

/* The code in this source file is responsible for generating
 * vma-to-fileOffset maps for both overlay and non-overlay SPU
 * applications.
 */

#include <linux/mm.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/elf.h>
#include <linux/slab.h>
#include "pr_util.h"


void vma_map_free(struct vma_to_fileoffset_map *map)
{
	while (map) {
		struct vma_to_fileoffset_map *next = map->next;
		kfree(map);
		map = next;
	}
}

unsigned int
vma_map_lookup(struct vma_to_fileoffset_map *map, unsigned int vma,
	       const struct spu *aSpu, int *grd_val)
{
	/*
	 * Default the offset to the physical address + a flag value.
	 * Addresses of dynamically generated code can't be found in the vma
	 * map.  For those addresses the flagged value will be sent on to
	 * the user space tools so they can be reported rather than just
	 * thrown away.
	 */
	u32 offset = 0x10000000 + vma;
	u32 ovly_grd;

	for (; map; map = map->next) {
		if (vma < map->vma || vma >= map->vma + map->size)
			continue;

		if (map->guard_ptr) {
			ovly_grd = *(u32 *)(aSpu->local_store + map->guard_ptr);
			if (ovly_grd != map->guard_val)
				continue;
			*grd_val = ovly_grd;
		}
		offset = vma - map->vma + map->offset;
		break;
	}

	return offset;
}

static struct vma_to_fileoffset_map *
vma_map_add(struct vma_to_fileoffset_map *map, unsigned int vma,
	    unsigned int size, unsigned int offset, unsigned int guard_ptr,
	    unsigned int guard_val)
{
	struct vma_to_fileoffset_map *new = kzalloc(sizeof(*new), GFP_KERNEL);

	if (!new) {
		printk(KERN_ERR "SPU_PROF: %s, line %d: malloc failed\n",
		       __func__, __LINE__);
		vma_map_free(map);
		return NULL;
	}

	new->next = map;
	new->vma = vma;
	new->size = size;
	new->offset = offset;
	new->guard_ptr = guard_ptr;
	new->guard_val = guard_val;

	return new;
}


/* Parse SPE ELF header and generate a list of vma_maps.
 * A pointer to the first vma_map in the generated list
 * of vma_maps is returned.  */
struct vma_to_fileoffset_map *create_vma_map(const struct spu *aSpu,
					     unsigned long __spu_elf_start)
{
	static const unsigned char expected[EI_PAD] = {
		[EI_MAG0] = ELFMAG0,
		[EI_MAG1] = ELFMAG1,
		[EI_MAG2] = ELFMAG2,
		[EI_MAG3] = ELFMAG3,
		[EI_CLASS] = ELFCLASS32,
		[EI_DATA] = ELFDATA2MSB,
		[EI_VERSION] = EV_CURRENT,
		[EI_OSABI] = ELFOSABI_NONE
	};

	int grd_val;
	struct vma_to_fileoffset_map *map = NULL;
	void __user *spu_elf_start = (void __user *)__spu_elf_start;
	struct spu_overlay_info ovly;
	unsigned int overlay_tbl_offset = -1;
	Elf32_Phdr __user *phdr_start;
	Elf32_Shdr __user *shdr_start;
	Elf32_Ehdr ehdr;
	Elf32_Phdr phdr;
	Elf32_Shdr shdr, shdr_str;
	Elf32_Sym sym;
	int i, j;
	char name[32];

	unsigned int ovly_table_sym = 0;
	unsigned int ovly_buf_table_sym = 0;
	unsigned int ovly_table_end_sym = 0;
	unsigned int ovly_buf_table_end_sym = 0;
	struct spu_overlay_info __user *ovly_table;
	unsigned int n_ovlys;

	/* Get and validate ELF header.	 */

	if (copy_from_user(&ehdr, spu_elf_start, sizeof (ehdr)))
		goto fail;

	if (memcmp(ehdr.e_ident, expected, EI_PAD) != 0) {
		printk(KERN_ERR "SPU_PROF: "
		       "%s, line %d: Unexpected e_ident parsing SPU ELF\n",
		       __func__, __LINE__);
		goto fail;
	}
	if (ehdr.e_machine != EM_SPU) {
		printk(KERN_ERR "SPU_PROF: "
		       "%s, line %d: Unexpected e_machine parsing SPU ELF\n",
		       __func__,  __LINE__);
		goto fail;
	}
	if (ehdr.e_type != ET_EXEC) {
		printk(KERN_ERR "SPU_PROF: "
		       "%s, line %d: Unexpected e_type parsing SPU ELF\n",
		       __func__, __LINE__);
		goto fail;
	}
	phdr_start = spu_elf_start + ehdr.e_phoff;
	shdr_start = spu_elf_start + ehdr.e_shoff;

	/* Traverse program headers.  */
	for (i = 0; i < ehdr.e_phnum; i++) {
		if (copy_from_user(&phdr, phdr_start + i, sizeof(phdr)))
			goto fail;

		if (phdr.p_type != PT_LOAD)
			continue;
		if (phdr.p_flags & (1 << 27))
			continue;

		map = vma_map_add(map, phdr.p_vaddr, phdr.p_memsz,
				  phdr.p_offset, 0, 0);
		if (!map)
			goto fail;
	}

	pr_debug("SPU_PROF: Created non-overlay maps\n");
	/* Traverse section table and search for overlay-related symbols.  */
	for (i = 0; i < ehdr.e_shnum; i++) {
		if (copy_from_user(&shdr, shdr_start + i, sizeof(shdr)))
			goto fail;

		if (shdr.sh_type != SHT_SYMTAB)
			continue;
		if (shdr.sh_entsize != sizeof (sym))
			continue;

		if (copy_from_user(&shdr_str,
				   shdr_start + shdr.sh_link,
				   sizeof(shdr)))
			goto fail;

		if (shdr_str.sh_type != SHT_STRTAB)
			goto fail;

		for (j = 0; j < shdr.sh_size / sizeof (sym); j++) {
			if (copy_from_user(&sym, spu_elf_start +
						 shdr.sh_offset +
						 j * sizeof (sym),
					   sizeof (sym)))
				goto fail;

			if (copy_from_user(name, 
					   spu_elf_start + shdr_str.sh_offset +
					   sym.st_name,
					   20))
				goto fail;

			if (memcmp(name, "_ovly_table", 12) == 0)
				ovly_table_sym = sym.st_value;
			if (memcmp(name, "_ovly_buf_table", 16) == 0)
				ovly_buf_table_sym = sym.st_value;
			if (memcmp(name, "_ovly_table_end", 16) == 0)
				ovly_table_end_sym = sym.st_value;
			if (memcmp(name, "_ovly_buf_table_end", 20) == 0)
				ovly_buf_table_end_sym = sym.st_value;
		}
	}

	/* If we don't have overlays, we're done.  */
	if (ovly_table_sym == 0 || ovly_buf_table_sym == 0
	    || ovly_table_end_sym == 0 || ovly_buf_table_end_sym == 0) {
		pr_debug("SPU_PROF: No overlay table found\n");
		goto out;
	} else {
		pr_debug("SPU_PROF: Overlay table found\n");
	}

	/* The _ovly_table symbol represents a table with one entry
	 * per overlay section.	 The _ovly_buf_table symbol represents
	 * a table with one entry per overlay region.
	 * The struct spu_overlay_info gives the structure of the _ovly_table
	 * entries.  The structure of _ovly_table_buf is simply one
	 * u32 word per entry.
	 */
	overlay_tbl_offset = vma_map_lookup(map, ovly_table_sym,
					    aSpu, &grd_val);
	if (overlay_tbl_offset > 0x10000000) {
		printk(KERN_ERR "SPU_PROF: "
		       "%s, line %d: Error finding SPU overlay table\n",
		       __func__, __LINE__);
		goto fail;
	}
	ovly_table = spu_elf_start + overlay_tbl_offset;

	n_ovlys = (ovly_table_end_sym -
		   ovly_table_sym) / sizeof (ovly);

	/* Traverse overlay table.  */
	for (i = 0; i < n_ovlys; i++) {
		if (copy_from_user(&ovly, ovly_table + i, sizeof (ovly)))
			goto fail;

		/* The ovly.vma/size/offset arguments are analogous to the same
		 * arguments used above for non-overlay maps.  The final two
		 * args are referred to as the guard pointer and the guard
		 * value.
		 * The guard pointer is an entry in the _ovly_buf_table,
		 * computed using ovly.buf as the index into the table.	 Since
		 * ovly.buf values begin at '1' to reference the first (or 0th)
		 * entry in the _ovly_buf_table, the computation subtracts 1
		 * from ovly.buf.
		 * The guard value is stored in the _ovly_buf_table entry and
		 * is an index (starting at 1) back to the _ovly_table entry
		 * that is pointing at this _ovly_buf_table entry.  So, for
		 * example, for an overlay scenario with one overlay segment
		 * and two overlay sections:
		 *	- Section 1 points to the first entry of the
		 *	  _ovly_buf_table, which contains a guard value
		 *	  of '1', referencing the first (index=0) entry of
		 *	  _ovly_table.
		 *	- Section 2 points to the second entry of the
		 *	  _ovly_buf_table, which contains a guard value
		 *	  of '2', referencing the second (index=1) entry of
		 *	  _ovly_table.
		 */
		map = vma_map_add(map, ovly.vma, ovly.size, ovly.offset,
				  ovly_buf_table_sym + (ovly.buf-1) * 4, i+1);
		if (!map)
			goto fail;
	}
	goto out;

 fail:
	map = NULL;
 out:
	return map;
}