cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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module.c (3552B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*  Kernel module help for powerpc.
      3    Copyright (C) 2001, 2003 Rusty Russell IBM Corporation.
      4    Copyright (C) 2008 Freescale Semiconductor, Inc.
      5
      6*/
      7#include <linux/elf.h>
      8#include <linux/moduleloader.h>
      9#include <linux/err.h>
     10#include <linux/vmalloc.h>
     11#include <linux/mm.h>
     12#include <linux/bug.h>
     13#include <asm/module.h>
     14#include <linux/uaccess.h>
     15#include <asm/firmware.h>
     16#include <linux/sort.h>
     17#include <asm/setup.h>
     18#include <asm/sections.h>
     19
     20static LIST_HEAD(module_bug_list);
     21
     22static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
     23				    const Elf_Shdr *sechdrs,
     24				    const char *name)
     25{
     26	char *secstrings;
     27	unsigned int i;
     28
     29	secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
     30	for (i = 1; i < hdr->e_shnum; i++)
     31		if (strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
     32			return &sechdrs[i];
     33	return NULL;
     34}
     35
     36int module_finalize(const Elf_Ehdr *hdr,
     37		const Elf_Shdr *sechdrs, struct module *me)
     38{
     39	const Elf_Shdr *sect;
     40	int rc;
     41
     42	rc = module_finalize_ftrace(me, sechdrs);
     43	if (rc)
     44		return rc;
     45
     46	/* Apply feature fixups */
     47	sect = find_section(hdr, sechdrs, "__ftr_fixup");
     48	if (sect != NULL)
     49		do_feature_fixups(cur_cpu_spec->cpu_features,
     50				  (void *)sect->sh_addr,
     51				  (void *)sect->sh_addr + sect->sh_size);
     52
     53	sect = find_section(hdr, sechdrs, "__mmu_ftr_fixup");
     54	if (sect != NULL)
     55		do_feature_fixups(cur_cpu_spec->mmu_features,
     56				  (void *)sect->sh_addr,
     57				  (void *)sect->sh_addr + sect->sh_size);
     58
     59#ifdef CONFIG_PPC64
     60	sect = find_section(hdr, sechdrs, "__fw_ftr_fixup");
     61	if (sect != NULL)
     62		do_feature_fixups(powerpc_firmware_features,
     63				  (void *)sect->sh_addr,
     64				  (void *)sect->sh_addr + sect->sh_size);
     65#endif /* CONFIG_PPC64 */
     66
     67#ifdef CONFIG_PPC64_ELF_ABI_V1
     68	sect = find_section(hdr, sechdrs, ".opd");
     69	if (sect != NULL) {
     70		me->arch.start_opd = sect->sh_addr;
     71		me->arch.end_opd = sect->sh_addr + sect->sh_size;
     72	}
     73#endif /* CONFIG_PPC64_ELF_ABI_V1 */
     74
     75#ifdef CONFIG_PPC_BARRIER_NOSPEC
     76	sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
     77	if (sect != NULL)
     78		do_barrier_nospec_fixups_range(barrier_nospec_enabled,
     79				  (void *)sect->sh_addr,
     80				  (void *)sect->sh_addr + sect->sh_size);
     81#endif /* CONFIG_PPC_BARRIER_NOSPEC */
     82
     83	sect = find_section(hdr, sechdrs, "__lwsync_fixup");
     84	if (sect != NULL)
     85		do_lwsync_fixups(cur_cpu_spec->cpu_features,
     86				 (void *)sect->sh_addr,
     87				 (void *)sect->sh_addr + sect->sh_size);
     88
     89	return 0;
     90}
     91
     92static __always_inline void *
     93__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
     94{
     95	pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
     96	gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);
     97
     98	/*
     99	 * Don't do huge page allocations for modules yet until more testing
    100	 * is done. STRICT_MODULE_RWX may require extra work to support this
    101	 * too.
    102	 */
    103	return __vmalloc_node_range(size, 1, start, end, gfp, prot,
    104				    VM_FLUSH_RESET_PERMS,
    105				    NUMA_NO_NODE, __builtin_return_address(0));
    106}
    107
    108void *module_alloc(unsigned long size)
    109{
    110#ifdef MODULES_VADDR
    111	unsigned long limit = (unsigned long)_etext - SZ_32M;
    112	void *ptr = NULL;
    113
    114	BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
    115
    116	/* First try within 32M limit from _etext to avoid branch trampolines */
    117	if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
    118		ptr = __module_alloc(size, limit, MODULES_END, true);
    119
    120	if (!ptr)
    121		ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);
    122
    123	return ptr;
    124#else
    125	return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
    126#endif
    127}