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-rw-r--r--arch/s390/kernel/module.c323
1 files changed, 212 insertions, 111 deletions
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 7845e15a17df..9d1f8a50f5a4 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
/*
* Kernel module help for s390.
*
@@ -8,29 +9,27 @@
*
* based on i386 version
* Copyright (C) 2001 Rusty Russell.
- *
- * 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.
- *
- * 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. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
+#include <linux/ftrace.h>
#include <linux/string.h>
#include <linux/kernel.h>
+#include <linux/kasan.h>
#include <linux/moduleloader.h>
#include <linux/bug.h>
+#include <linux/memory.h>
+#include <linux/execmem.h>
+#include <asm/arch-stackprotector.h>
+#include <asm/alternative.h>
+#include <asm/nospec-branch.h>
+#include <asm/facility.h>
+#include <asm/ftrace.lds.h>
+#include <asm/set_memory.h>
+#include <asm/setup.h>
+#include <asm/asm-offsets.h>
#if 0
#define DEBUGP printk
@@ -38,31 +37,23 @@
#define DEBUGP(fmt , ...)
#endif
-#ifndef CONFIG_64BIT
-#define PLT_ENTRY_SIZE 12
-#else /* CONFIG_64BIT */
-#define PLT_ENTRY_SIZE 20
-#endif /* CONFIG_64BIT */
+#define PLT_ENTRY_SIZE 22
-#ifdef CONFIG_64BIT
-void *module_alloc(unsigned long size)
+#ifdef CONFIG_FUNCTION_TRACER
+void module_arch_cleanup(struct module *mod)
{
- if (PAGE_ALIGN(size) > MODULES_LEN)
- return NULL;
- return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
- GFP_KERNEL, PAGE_KERNEL, -1,
- __builtin_return_address(0));
+ execmem_free(mod->arch.trampolines_start);
}
#endif
-/* Free memory returned from module_alloc */
-void module_free(struct module *mod, void *module_region)
+void module_arch_freeing_init(struct module *mod)
{
- if (mod) {
- vfree(mod->arch.syminfo);
- mod->arch.syminfo = NULL;
- }
- vfree(module_region);
+ if (is_livepatch_module(mod) &&
+ mod->state == MODULE_STATE_LIVE)
+ return;
+
+ vfree(mod->arch.syminfo);
+ mod->arch.syminfo = NULL;
}
static void check_rela(Elf_Rela *rela, struct module *me)
@@ -122,6 +113,7 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
Elf_Rela *rela;
char *strings;
int nrela, i, j;
+ struct module_memory *mod_mem;
/* Find symbol table and string table. */
symtab = NULL;
@@ -138,8 +130,8 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
/* Allocate one syminfo structure per symbol. */
me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
- me->arch.syminfo = vmalloc(me->arch.nsyms *
- sizeof(struct mod_arch_syminfo));
+ me->arch.syminfo = vmalloc(array_size(sizeof(struct mod_arch_syminfo),
+ me->arch.nsyms));
if (!me->arch.syminfo)
return -ENOMEM;
symbols = (void *) hdr + symtab->sh_offset;
@@ -169,19 +161,26 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
/* Increase core size by size of got & plt and set start
offsets for got and plt. */
- me->core_size = ALIGN(me->core_size, 4);
- me->arch.got_offset = me->core_size;
- me->core_size += me->arch.got_size;
- me->arch.plt_offset = me->core_size;
- me->core_size += me->arch.plt_size;
+ mod_mem = &me->mem[MOD_TEXT];
+ mod_mem->size = ALIGN(mod_mem->size, 4);
+ me->arch.got_offset = mod_mem->size;
+ mod_mem->size += me->arch.got_size;
+ me->arch.plt_offset = mod_mem->size;
+ if (me->arch.plt_size) {
+ if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)
+ me->arch.plt_size += PLT_ENTRY_SIZE;
+ mod_mem->size += me->arch.plt_size;
+ }
return 0;
}
static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
- int sign, int bits, int shift)
+ int sign, int bits, int shift,
+ void *(*write)(void *dest, const void *src, size_t len))
{
unsigned long umax;
long min, max;
+ void *dest = (void *)loc;
if (val & ((1UL << shift) - 1))
return -ENOEXEC;
@@ -198,26 +197,33 @@ static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
return -ENOEXEC;
}
- if (bits == 8)
- *(unsigned char *) loc = val;
- else if (bits == 12)
- *(unsigned short *) loc = (val & 0xfff) |
+ if (bits == 8) {
+ unsigned char tmp = val;
+ write(dest, &tmp, 1);
+ } else if (bits == 12) {
+ unsigned short tmp = (val & 0xfff) |
(*(unsigned short *) loc & 0xf000);
- else if (bits == 16)
- *(unsigned short *) loc = val;
- else if (bits == 20)
- *(unsigned int *) loc = (val & 0xfff) << 16 |
- (val & 0xff000) >> 4 |
- (*(unsigned int *) loc & 0xf00000ff);
- else if (bits == 32)
- *(unsigned int *) loc = val;
- else if (bits == 64)
- *(unsigned long *) loc = val;
+ write(dest, &tmp, 2);
+ } else if (bits == 16) {
+ unsigned short tmp = val;
+ write(dest, &tmp, 2);
+ } else if (bits == 20) {
+ unsigned int tmp = (val & 0xfff) << 16 |
+ (val & 0xff000) >> 4 | (*(unsigned int *) loc & 0xf00000ff);
+ write(dest, &tmp, 4);
+ } else if (bits == 32) {
+ unsigned int tmp = val;
+ write(dest, &tmp, 4);
+ } else if (bits == 64) {
+ unsigned long tmp = val;
+ write(dest, &tmp, 8);
+ }
return 0;
}
static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
- const char *strtab, struct module *me)
+ const char *strtab, struct module *me,
+ void *(*write)(void *dest, const void *src, size_t len))
{
struct mod_arch_syminfo *info;
Elf_Addr loc, val;
@@ -245,17 +251,17 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_64: /* Direct 64 bit. */
val += rela->r_addend;
if (r_type == R_390_8)
- rc = apply_rela_bits(loc, val, 0, 8, 0);
+ rc = apply_rela_bits(loc, val, 0, 8, 0, write);
else if (r_type == R_390_12)
- rc = apply_rela_bits(loc, val, 0, 12, 0);
+ rc = apply_rela_bits(loc, val, 0, 12, 0, write);
else if (r_type == R_390_16)
- rc = apply_rela_bits(loc, val, 0, 16, 0);
+ rc = apply_rela_bits(loc, val, 0, 16, 0, write);
else if (r_type == R_390_20)
- rc = apply_rela_bits(loc, val, 1, 20, 0);
+ rc = apply_rela_bits(loc, val, 1, 20, 0, write);
else if (r_type == R_390_32)
- rc = apply_rela_bits(loc, val, 0, 32, 0);
+ rc = apply_rela_bits(loc, val, 0, 32, 0, write);
else if (r_type == R_390_64)
- rc = apply_rela_bits(loc, val, 0, 64, 0);
+ rc = apply_rela_bits(loc, val, 0, 64, 0, write);
break;
case R_390_PC16: /* PC relative 16 bit. */
case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */
@@ -264,15 +270,15 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_PC64: /* PC relative 64 bit. */
val += rela->r_addend - loc;
if (r_type == R_390_PC16)
- rc = apply_rela_bits(loc, val, 1, 16, 0);
+ rc = apply_rela_bits(loc, val, 1, 16, 0, write);
else if (r_type == R_390_PC16DBL)
- rc = apply_rela_bits(loc, val, 1, 16, 1);
+ rc = apply_rela_bits(loc, val, 1, 16, 1, write);
else if (r_type == R_390_PC32DBL)
- rc = apply_rela_bits(loc, val, 1, 32, 1);
+ rc = apply_rela_bits(loc, val, 1, 32, 1, write);
else if (r_type == R_390_PC32)
- rc = apply_rela_bits(loc, val, 1, 32, 0);
+ rc = apply_rela_bits(loc, val, 1, 32, 0, write);
else if (r_type == R_390_PC64)
- rc = apply_rela_bits(loc, val, 1, 64, 0);
+ rc = apply_rela_bits(loc, val, 1, 64, 0, write);
break;
case R_390_GOT12: /* 12 bit GOT offset. */
case R_390_GOT16: /* 16 bit GOT offset. */
@@ -287,33 +293,34 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_GOTPLT64: /* 64 bit offset to jump slot. */
case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */
if (info->got_initialized == 0) {
- Elf_Addr *gotent;
+ Elf_Addr *gotent = me->mem[MOD_TEXT].base +
+ me->arch.got_offset +
+ info->got_offset;
- gotent = me->module_core + me->arch.got_offset +
- info->got_offset;
- *gotent = val;
+ write(gotent, &val, sizeof(*gotent));
info->got_initialized = 1;
}
val = info->got_offset + rela->r_addend;
if (r_type == R_390_GOT12 ||
r_type == R_390_GOTPLT12)
- rc = apply_rela_bits(loc, val, 0, 12, 0);
+ rc = apply_rela_bits(loc, val, 0, 12, 0, write);
else if (r_type == R_390_GOT16 ||
r_type == R_390_GOTPLT16)
- rc = apply_rela_bits(loc, val, 0, 16, 0);
+ rc = apply_rela_bits(loc, val, 0, 16, 0, write);
else if (r_type == R_390_GOT20 ||
r_type == R_390_GOTPLT20)
- rc = apply_rela_bits(loc, val, 1, 20, 0);
+ rc = apply_rela_bits(loc, val, 1, 20, 0, write);
else if (r_type == R_390_GOT32 ||
r_type == R_390_GOTPLT32)
- rc = apply_rela_bits(loc, val, 0, 32, 0);
+ rc = apply_rela_bits(loc, val, 0, 32, 0, write);
else if (r_type == R_390_GOT64 ||
r_type == R_390_GOTPLT64)
- rc = apply_rela_bits(loc, val, 0, 64, 0);
+ rc = apply_rela_bits(loc, val, 0, 64, 0, write);
else if (r_type == R_390_GOTENT ||
r_type == R_390_GOTPLTENT) {
- val += (Elf_Addr) me->module_core - loc;
- rc = apply_rela_bits(loc, val, 1, 32, 1);
+ val += (Elf_Addr)me->mem[MOD_TEXT].base +
+ me->arch.got_offset - loc;
+ rc = apply_rela_bits(loc, val, 1, 32, 1, write);
}
break;
case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */
@@ -324,20 +331,28 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */
case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
if (info->plt_initialized == 0) {
- unsigned int *ip;
- ip = me->module_core + me->arch.plt_offset +
- info->plt_offset;
-#ifndef CONFIG_64BIT
- ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */
- ip[1] = 0x100607f1;
- ip[2] = val;
-#else /* CONFIG_64BIT */
- ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
- ip[1] = 0x100a0004;
- ip[2] = 0x07f10000;
- ip[3] = (unsigned int) (val >> 32);
- ip[4] = (unsigned int) val;
-#endif /* CONFIG_64BIT */
+ unsigned char insn[PLT_ENTRY_SIZE];
+ char *plt_base;
+ char *ip;
+
+ plt_base = me->mem[MOD_TEXT].base + me->arch.plt_offset;
+ ip = plt_base + info->plt_offset;
+ *(int *)insn = 0x0d10e310; /* basr 1,0 */
+ *(int *)&insn[4] = 0x100c0004; /* lg 1,12(1) */
+ if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {
+ char *jump_r1;
+
+ jump_r1 = plt_base + me->arch.plt_size -
+ PLT_ENTRY_SIZE;
+ /* brcl 0xf,__jump_r1 */
+ *(short *)&insn[8] = 0xc0f4;
+ *(int *)&insn[10] = (jump_r1 - (ip + 8)) / 2;
+ } else {
+ *(int *)&insn[8] = 0x07f10000; /* br %r1 */
+ }
+ *(long *)&insn[14] = val;
+
+ write(ip, insn, sizeof(insn));
info->plt_initialized = 1;
}
if (r_type == R_390_PLTOFF16 ||
@@ -350,44 +365,44 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
val - loc + 0xffffUL < 0x1ffffeUL) ||
(r_type == R_390_PLT32DBL &&
val - loc + 0xffffffffULL < 0x1fffffffeULL)))
- val = (Elf_Addr) me->module_core +
+ val = (Elf_Addr) me->mem[MOD_TEXT].base +
me->arch.plt_offset +
info->plt_offset;
val += rela->r_addend - loc;
}
if (r_type == R_390_PLT16DBL)
- rc = apply_rela_bits(loc, val, 1, 16, 1);
+ rc = apply_rela_bits(loc, val, 1, 16, 1, write);
else if (r_type == R_390_PLTOFF16)
- rc = apply_rela_bits(loc, val, 0, 16, 0);
+ rc = apply_rela_bits(loc, val, 0, 16, 0, write);
else if (r_type == R_390_PLT32DBL)
- rc = apply_rela_bits(loc, val, 1, 32, 1);
+ rc = apply_rela_bits(loc, val, 1, 32, 1, write);
else if (r_type == R_390_PLT32 ||
r_type == R_390_PLTOFF32)
- rc = apply_rela_bits(loc, val, 0, 32, 0);
+ rc = apply_rela_bits(loc, val, 0, 32, 0, write);
else if (r_type == R_390_PLT64 ||
r_type == R_390_PLTOFF64)
- rc = apply_rela_bits(loc, val, 0, 64, 0);
+ rc = apply_rela_bits(loc, val, 0, 64, 0, write);
break;
case R_390_GOTOFF16: /* 16 bit offset to GOT. */
case R_390_GOTOFF32: /* 32 bit offset to GOT. */
case R_390_GOTOFF64: /* 64 bit offset to GOT. */
val = val + rela->r_addend -
- ((Elf_Addr) me->module_core + me->arch.got_offset);
+ ((Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset);
if (r_type == R_390_GOTOFF16)
- rc = apply_rela_bits(loc, val, 0, 16, 0);
+ rc = apply_rela_bits(loc, val, 0, 16, 0, write);
else if (r_type == R_390_GOTOFF32)
- rc = apply_rela_bits(loc, val, 0, 32, 0);
+ rc = apply_rela_bits(loc, val, 0, 32, 0, write);
else if (r_type == R_390_GOTOFF64)
- rc = apply_rela_bits(loc, val, 0, 64, 0);
+ rc = apply_rela_bits(loc, val, 0, 64, 0, write);
break;
case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
- val = (Elf_Addr) me->module_core + me->arch.got_offset +
+ val = (Elf_Addr) me->mem[MOD_TEXT].base + me->arch.got_offset +
rela->r_addend - loc;
if (r_type == R_390_GOTPC)
- rc = apply_rela_bits(loc, val, 1, 32, 0);
+ rc = apply_rela_bits(loc, val, 1, 32, 0, write);
else if (r_type == R_390_GOTPCDBL)
- rc = apply_rela_bits(loc, val, 1, 32, 1);
+ rc = apply_rela_bits(loc, val, 1, 32, 1, write);
break;
case R_390_COPY:
case R_390_GLOB_DAT: /* Create GOT entry. */
@@ -411,9 +426,10 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
return 0;
}
-int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+static int __apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
unsigned int symindex, unsigned int relsec,
- struct module *me)
+ struct module *me,
+ void *(*write)(void *dest, const void *src, size_t len))
{
Elf_Addr base;
Elf_Sym *symtab;
@@ -429,18 +445,103 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
for (i = 0; i < n; i++, rela++) {
- rc = apply_rela(rela, base, symtab, strtab, me);
+ rc = apply_rela(rela, base, symtab, strtab, me, write);
if (rc)
return rc;
}
return 0;
}
+int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+ unsigned int symindex, unsigned int relsec,
+ struct module *me)
+{
+ bool early = me->state == MODULE_STATE_UNFORMED;
+ void *(*write)(void *, const void *, size_t) = memcpy;
+
+ if (!early)
+ write = s390_kernel_write;
+
+ return __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
+ write);
+}
+
+#ifdef CONFIG_FUNCTION_TRACER
+static int module_alloc_ftrace_hotpatch_trampolines(struct module *me,
+ const Elf_Shdr *s)
+{
+ char *start, *end;
+ int numpages;
+ size_t size;
+
+ size = FTRACE_HOTPATCH_TRAMPOLINES_SIZE(s->sh_size);
+ numpages = DIV_ROUND_UP(size, PAGE_SIZE);
+ start = execmem_alloc(EXECMEM_FTRACE, numpages * PAGE_SIZE);
+ if (!start)
+ return -ENOMEM;
+ set_memory_rox((unsigned long)start, numpages);
+ end = start + size;
+
+ me->arch.trampolines_start = (struct ftrace_hotpatch_trampoline *)start;
+ me->arch.trampolines_end = (struct ftrace_hotpatch_trampoline *)end;
+ me->arch.next_trampoline = me->arch.trampolines_start;
+
+ return 0;
+}
+#endif /* CONFIG_FUNCTION_TRACER */
+
int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
- vfree(me->arch.syminfo);
- me->arch.syminfo = NULL;
- return 0;
+ const Elf_Shdr *s;
+ char *secstrings, *secname;
+ void *aseg;
+ int rc = 0;
+
+ if (IS_ENABLED(CONFIG_EXPOLINE) &&
+ !nospec_disable && me->arch.plt_size) {
+ unsigned int *ij;
+
+ ij = me->mem[MOD_TEXT].base + me->arch.plt_offset +
+ me->arch.plt_size - PLT_ENTRY_SIZE;
+ ij[0] = 0xc6000000; /* exrl %r0,.+10 */
+ ij[1] = 0x0005a7f4; /* j . */
+ ij[2] = 0x000007f1; /* br %r1 */
+ }
+
+ secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+ for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
+ aseg = (void *) s->sh_addr;
+ secname = secstrings + s->sh_name;
+
+ if (!strcmp(".altinstructions", secname))
+ /* patch .altinstructions */
+ apply_alternatives(aseg, aseg + s->sh_size);
+
+ if (IS_ENABLED(CONFIG_EXPOLINE) &&
+ (str_has_prefix(secname, ".s390_indirect")))
+ nospec_revert(aseg, aseg + s->sh_size);
+
+ if (IS_ENABLED(CONFIG_EXPOLINE) &&
+ (str_has_prefix(secname, ".s390_return")))
+ nospec_revert(aseg, aseg + s->sh_size);
+
+ if (IS_ENABLED(CONFIG_STACKPROTECTOR) &&
+ (str_has_prefix(secname, "__stack_protector_loc"))) {
+ rc = stack_protector_apply(aseg, aseg + s->sh_size);
+ if (rc)
+ break;
+ }
+
+#ifdef CONFIG_FUNCTION_TRACER
+ if (!strcmp(FTRACE_CALLSITE_SECTION, secname)) {
+ rc = module_alloc_ftrace_hotpatch_trampolines(me, s);
+ if (rc)
+ break;
+ }
+#endif /* CONFIG_FUNCTION_TRACER */
+ }
+
+ return rc;
}
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