cregit-Linux how code gets into the kernel

Release 4.14 arch/tile/kernel/module.c

Directory: arch/tile/kernel
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   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, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * Based on i386 version, copyright (C) 2001 Rusty Russell.
 */

#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/pgtable.h>
#include <asm/homecache.h>
#include <arch/opcode.h>

#ifdef MODULE_DEBUG

#define DEBUGP printk
#else

#define DEBUGP(fmt...)
#endif

/*
 * Allocate some address space in the range MEM_MODULE_START to
 * MEM_MODULE_END and populate it with memory.
 */

void *module_alloc(unsigned long size) { struct page **pages; pgprot_t prot_rwx = __pgprot(_PAGE_KERNEL | _PAGE_KERNEL_EXEC); struct vm_struct *area; int i = 0; int npages; npages = (size + PAGE_SIZE - 1) / PAGE_SIZE; pages = kmalloc_array(npages, sizeof(*pages), GFP_KERNEL); if (pages == NULL) return NULL; for (; i < npages; ++i) { pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); if (!pages[i]) goto free_pages; } area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END); if (!area) goto free_pages; area->nr_pages = npages; area->pages = pages; if (map_vm_area(area, prot_rwx, pages)) { vunmap(area->addr); goto free_pages; } return area->addr; free_pages: while (--i >= 0) __free_page(pages[i]); kfree(pages); return NULL; }

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Chris Metcalf18996.43%250.00%
SF Markus Elfring73.57%250.00%
Total196100.00%4100.00%

/* Free memory returned from module_alloc */
void module_memfree(void *module_region) { vfree(module_region); /* Globally flush the L1 icache. */ flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask, 0, 0, 0, NULL, NULL, 0); /* * FIXME: Add module_arch_freeing_init to trim exception * table entries. */ }

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PersonTokensPropCommitsCommitProp
Chris Metcalf3594.59%250.00%
Rusty Russell25.41%250.00%
Total37100.00%4100.00%

#ifdef __tilegx__ /* * Validate that the high 16 bits of "value" is just the sign-extension of * the low 48 bits. */
static int validate_hw2_last(long value, struct module *me) { if (((value << 16) >> 16) != value) { pr_warn("module %s: Out of range HW2_LAST value %#lx\n", me->name, value); return 0; } return 1; }

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Chris Metcalf4697.87%150.00%
Joe Perches12.13%150.00%
Total47100.00%2100.00%

/* * Validate that "value" isn't too big to hold in a JumpOff relocation. */
static int validate_jumpoff(long value) { /* Determine size of jump offset. */ int shift = __builtin_clzl(get_JumpOff_X1(create_JumpOff_X1(-1))); /* Check to see if it fits into the relocation slot. */ long f = get_JumpOff_X1(create_JumpOff_X1(value)); f = (f << shift) >> shift; return f == value; }

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Chris Metcalf52100.00%1100.00%
Total52100.00%1100.00%

#endif
int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { unsigned int i; Elf_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf_Sym *sym; u64 *location; unsigned long value; DEBUGP("Applying relocate section %u to %u\n", relsec, sechdrs[relsec].sh_info); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; /* * This is the symbol it is referring to. * Note that all undefined symbols have been resolved. */ sym = (Elf_Sym *)sechdrs[symindex].sh_addr + ELF_R_SYM(rel[i].r_info); value = sym->st_value + rel[i].r_addend; switch (ELF_R_TYPE(rel[i].r_info)) { #ifdef __LITTLE_ENDIAN # define MUNGE(func) \ (*location = ((*location & ~func(-1)) | func(value))) #else /* * Instructions are always little-endian, so when we read them as data, * we have to swap them around before and after modifying them. */ # define MUNGE(func) \ (*location = swab64((swab64(*location) & ~func(-1)) | func(value))) #endif #ifndef __tilegx__ case R_TILE_32: *(uint32_t *)location = value; break; case R_TILE_IMM16_X0_HA: value = (value + 0x8000) >> 16; /*FALLTHROUGH*/ case R_TILE_IMM16_X0_LO: MUNGE(create_Imm16_X0); break; case R_TILE_IMM16_X1_HA: value = (value + 0x8000) >> 16; /*FALLTHROUGH*/ case R_TILE_IMM16_X1_LO: MUNGE(create_Imm16_X1); break; case R_TILE_JOFFLONG_X1: value -= (unsigned long) location; /* pc-relative */ value = (long) value >> 3; /* count by instrs */ MUNGE(create_JOffLong_X1); break; #else case R_TILEGX_64: *location = value; break; case R_TILEGX_IMM16_X0_HW2_LAST: if (!validate_hw2_last(value, me)) return -ENOEXEC; value >>= 16; /*FALLTHROUGH*/ case R_TILEGX_IMM16_X0_HW1: value >>= 16; /*FALLTHROUGH*/ case R_TILEGX_IMM16_X0_HW0: MUNGE(create_Imm16_X0); break; case R_TILEGX_IMM16_X1_HW2_LAST: if (!validate_hw2_last(value, me)) return -ENOEXEC; value >>= 16; /*FALLTHROUGH*/ case R_TILEGX_IMM16_X1_HW1: value >>= 16; /*FALLTHROUGH*/ case R_TILEGX_IMM16_X1_HW0: MUNGE(create_Imm16_X1); break; case R_TILEGX_JUMPOFF_X1: value -= (unsigned long) location; /* pc-relative */ value = (long) value >> 3; /* count by instrs */ if (!validate_jumpoff(value)) { pr_warn("module %s: Out of range jump to %#llx at %#llx (%p)\n", me->name, sym->st_value + rel[i].r_addend, rel[i].r_offset, location); return -ENOEXEC; } MUNGE(create_JumpOff_X1); break; #endif #undef MUNGE default: pr_err("module %s: Unknown relocation: %d\n", me->name, (int) ELF_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf48299.59%375.00%
Joe Perches20.41%125.00%
Total484100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Chris Metcalf85998.62%654.55%
SF Markus Elfring70.80%218.18%
Joe Perches30.34%19.09%
Rusty Russell20.23%218.18%
Total871100.00%11100.00%
Directory: arch/tile/kernel
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