cregit-Linux how code gets into the kernel

Release 4.14 arch/powerpc/oprofile/cell/vma_map.c

/*
 * 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; } }

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Bob Nelson34100.00%1100.00%
Total34100.00%1100.00%


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; }

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Bob Nelson123100.00%1100.00%
Total123100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Bob Nelson11299.12%150.00%
Harvey Harrison10.88%150.00%
Total113100.00%2100.00%

/* 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; }

Contributors

PersonTokensPropCommitsCommitProp
Bob Nelson78696.32%125.00%
Al Viro242.94%125.00%
Harvey Harrison40.49%125.00%
Roel Kluin20.25%125.00%
Total816100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Bob Nelson107396.93%120.00%
Al Viro242.17%120.00%
Harvey Harrison50.45%120.00%
Tejun Heo30.27%120.00%
Roel Kluin20.18%120.00%
Total1107100.00%5100.00%
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