/*
* 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 "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(struct vma_to_fileoffset_map), 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;
}
