linux/arch/powerpc/kernel/module.c
Jordan Niethe 4fcc636615 powerpc/modules: Make module_alloc() Strict Module RWX aware
Make module_alloc() use PAGE_KERNEL protections instead of
PAGE_KERNEL_EXEX if Strict Module RWX is enabled.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-4-jniethe5@gmail.com
2021-06-21 21:13:20 +10:00

127 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* Kernel module help for powerpc.
Copyright (C) 2001, 2003 Rusty Russell IBM Corporation.
Copyright (C) 2008 Freescale Semiconductor, Inc.
*/
#include <linux/elf.h>
#include <linux/moduleloader.h>
#include <linux/err.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/bug.h>
#include <asm/module.h>
#include <linux/uaccess.h>
#include <asm/firmware.h>
#include <linux/sort.h>
#include <asm/setup.h>
#include <asm/sections.h>
static LIST_HEAD(module_bug_list);
static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
const char *name)
{
char *secstrings;
unsigned int i;
secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++)
if (strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
return &sechdrs[i];
return NULL;
}
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs, struct module *me)
{
const Elf_Shdr *sect;
int rc;
rc = module_finalize_ftrace(me, sechdrs);
if (rc)
return rc;
/* Apply feature fixups */
sect = find_section(hdr, sechdrs, "__ftr_fixup");
if (sect != NULL)
do_feature_fixups(cur_cpu_spec->cpu_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
sect = find_section(hdr, sechdrs, "__mmu_ftr_fixup");
if (sect != NULL)
do_feature_fixups(cur_cpu_spec->mmu_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
#ifdef CONFIG_PPC64
sect = find_section(hdr, sechdrs, "__fw_ftr_fixup");
if (sect != NULL)
do_feature_fixups(powerpc_firmware_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
#endif /* CONFIG_PPC64 */
#ifdef PPC64_ELF_ABI_v1
sect = find_section(hdr, sechdrs, ".opd");
if (sect != NULL) {
me->arch.start_opd = sect->sh_addr;
me->arch.end_opd = sect->sh_addr + sect->sh_size;
}
#endif /* PPC64_ELF_ABI_v1 */
#ifdef CONFIG_PPC_BARRIER_NOSPEC
sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
if (sect != NULL)
do_barrier_nospec_fixups_range(barrier_nospec_enabled,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
#endif /* CONFIG_PPC_BARRIER_NOSPEC */
sect = find_section(hdr, sechdrs, "__lwsync_fixup");
if (sect != NULL)
do_lwsync_fixups(cur_cpu_spec->cpu_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
return 0;
}
static __always_inline void *
__module_alloc(unsigned long size, unsigned long start, unsigned long end)
{
pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
/*
* Don't do huge page allocations for modules yet until more testing
* is done. STRICT_MODULE_RWX may require extra work to support this
* too.
*/
return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, prot,
VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
NUMA_NO_NODE, __builtin_return_address(0));
}
void *module_alloc(unsigned long size)
{
#ifdef MODULES_VADDR
unsigned long limit = (unsigned long)_etext - SZ_32M;
void *ptr = NULL;
BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
/* First try within 32M limit from _etext to avoid branch trampolines */
if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
ptr = __module_alloc(size, limit, MODULES_END);
if (!ptr)
ptr = __module_alloc(size, MODULES_VADDR, MODULES_END);
return ptr;
#else
return __module_alloc(size, VMALLOC_START, VMALLOC_END);
#endif
}