Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 478 insertions, 0 deletions

diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
new file mode 100644
index 000000000..d298d3cb4
--- /dev/null
+++ b/arch/s390/kernel/module.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Kernel module help for s390.
+ *
+ *  S390 version
+ *    Copyright IBM Corp. 2002, 2003
+ *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
+ *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  based on i386 version
+ *    Copyright (C) 2001 Rusty Russell.
+ */
+#include <linux/module.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/moduleloader.h>
+#include <linux/bug.h>
+#include <asm/alternative.h>
+#include <asm/nospec-branch.h>
+#include <asm/facility.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...)
+#endif
+
+#define PLT_ENTRY_SIZE 20
+
+void *module_alloc(unsigned long size)
+{
+	if (PAGE_ALIGN(size) > MODULES_LEN)
+		return NULL;
+	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
+				    GFP_KERNEL, PAGE_KERNEL_EXEC,
+				    0, NUMA_NO_NODE,
+				    __builtin_return_address(0));
+}
+
+void module_arch_freeing_init(struct module *mod)
+{
+	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)
+{
+	struct mod_arch_syminfo *info;
+
+	info = me->arch.syminfo + ELF_R_SYM (rela->r_info);
+	switch (ELF_R_TYPE (rela->r_info)) {
+	case R_390_GOT12:	/* 12 bit GOT offset.  */
+	case R_390_GOT16:	/* 16 bit GOT offset.  */
+	case R_390_GOT20:	/* 20 bit GOT offset.  */
+	case R_390_GOT32:	/* 32 bit GOT offset.  */
+	case R_390_GOT64:	/* 64 bit GOT offset.  */
+	case R_390_GOTENT:	/* 32 bit PC rel. to GOT entry shifted by 1. */
+	case R_390_GOTPLT12:	/* 12 bit offset to jump slot.	*/
+	case R_390_GOTPLT16:	/* 16 bit offset to jump slot.  */
+	case R_390_GOTPLT20:	/* 20 bit offset to jump slot.  */
+	case R_390_GOTPLT32:	/* 32 bit offset to jump slot.  */
+	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_offset == -1UL) {
+			info->got_offset = me->arch.got_size;
+			me->arch.got_size += sizeof(void*);
+		}
+		break;
+	case R_390_PLT16DBL:	/* 16 bit PC rel. PLT shifted by 1.  */
+	case R_390_PLT32DBL:	/* 32 bit PC rel. PLT shifted by 1.  */
+	case R_390_PLT32:	/* 32 bit PC relative PLT address.  */
+	case R_390_PLT64:	/* 64 bit PC relative PLT address.  */
+	case R_390_PLTOFF16:	/* 16 bit offset from GOT to PLT. */
+	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_offset == -1UL) {
+			info->plt_offset = me->arch.plt_size;
+			me->arch.plt_size += PLT_ENTRY_SIZE;
+		}
+		break;
+	case R_390_COPY:
+	case R_390_GLOB_DAT:
+	case R_390_JMP_SLOT:
+	case R_390_RELATIVE:
+		/* Only needed if we want to support loading of 
+		   modules linked with -shared. */
+		break;
+	}
+}
+
+/*
+ * Account for GOT and PLT relocations. We can't add sections for
+ * got and plt but we can increase the core module size.
+ */
+int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+			      char *secstrings, struct module *me)
+{
+	Elf_Shdr *symtab;
+	Elf_Sym *symbols;
+	Elf_Rela *rela;
+	char *strings;
+	int nrela, i, j;
+
+	/* Find symbol table and string table. */
+	symtab = NULL;
+	for (i = 0; i < hdr->e_shnum; i++)
+		switch (sechdrs[i].sh_type) {
+		case SHT_SYMTAB:
+			symtab = sechdrs + i;
+			break;
+		}
+	if (!symtab) {
+		printk(KERN_ERR "module %s: no symbol table\n", me->name);
+		return -ENOEXEC;
+	}
+
+	/* Allocate one syminfo structure per symbol. */
+	me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym);
+	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;
+	strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset;
+	for (i = 0; i < me->arch.nsyms; i++) {
+		if (symbols[i].st_shndx == SHN_UNDEF &&
+		    strcmp(strings + symbols[i].st_name,
+			   "_GLOBAL_OFFSET_TABLE_") == 0)
+			/* "Define" it as absolute. */
+			symbols[i].st_shndx = SHN_ABS;
+		me->arch.syminfo[i].got_offset = -1UL;
+		me->arch.syminfo[i].plt_offset = -1UL;
+		me->arch.syminfo[i].got_initialized = 0;
+		me->arch.syminfo[i].plt_initialized = 0;
+	}
+
+	/* Search for got/plt relocations. */
+	me->arch.got_size = me->arch.plt_size = 0;
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if (sechdrs[i].sh_type != SHT_RELA)
+			continue;
+		nrela = sechdrs[i].sh_size / sizeof(Elf_Rela);
+		rela = (void *) hdr + sechdrs[i].sh_offset;
+		for (j = 0; j < nrela; j++)
+			check_rela(rela + j, me);
+	}
+
+	/* Increase core size by size of got & plt and set start
+	   offsets for got and plt. */
+	me->core_layout.size = ALIGN(me->core_layout.size, 4);
+	me->arch.got_offset = me->core_layout.size;
+	me->core_layout.size += me->arch.got_size;
+	me->arch.plt_offset = me->core_layout.size;
+	if (me->arch.plt_size) {
+		if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable)
+			me->arch.plt_size += PLT_ENTRY_SIZE;
+		me->core_layout.size += me->arch.plt_size;
+	}
+	return 0;
+}
+
+static int apply_rela_bits(Elf_Addr loc, Elf_Addr val,
+			   int sign, int bits, int shift)
+{
+	unsigned long umax;
+	long min, max;
+
+	if (val & ((1UL << shift) - 1))
+		return -ENOEXEC;
+	if (sign) {
+		val = (Elf_Addr)(((long) val) >> shift);
+		min = -(1L << (bits - 1));
+		max = (1L << (bits - 1)) - 1;
+		if ((long) val < min || (long) val > max)
+			return -ENOEXEC;
+	} else {
+		val >>= shift;
+		umax = ((1UL << (bits - 1)) << 1) - 1;
+		if ((unsigned long) val > umax)
+			return -ENOEXEC;
+	}
+
+	if (bits == 8)
+		*(unsigned char *) loc = val;
+	else if (bits == 12)
+		*(unsigned short *) loc = (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;
+	return 0;
+}
+
+static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
+		      const char *strtab, struct module *me)
+{
+	struct mod_arch_syminfo *info;
+	Elf_Addr loc, val;
+	int r_type, r_sym;
+	int rc = -ENOEXEC;
+
+	/* This is where to make the change */
+	loc = base + rela->r_offset;
+	/* This is the symbol it is referring to.  Note that all
+	   undefined symbols have been resolved.  */
+	r_sym = ELF_R_SYM(rela->r_info);
+	r_type = ELF_R_TYPE(rela->r_info);
+	info = me->arch.syminfo + r_sym;
+	val = symtab[r_sym].st_value;
+
+	switch (r_type) {
+	case R_390_NONE:	/* No relocation.  */
+		rc = 0;
+		break;
+	case R_390_8:		/* Direct 8 bit.   */
+	case R_390_12:		/* Direct 12 bit.  */
+	case R_390_16:		/* Direct 16 bit.  */
+	case R_390_20:		/* Direct 20 bit.  */
+	case R_390_32:		/* Direct 32 bit.  */
+	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);
+		else if (r_type == R_390_12)
+			rc = apply_rela_bits(loc, val, 0, 12, 0);
+		else if (r_type == R_390_16)
+			rc = apply_rela_bits(loc, val, 0, 16, 0);
+		else if (r_type == R_390_20)
+			rc = apply_rela_bits(loc, val, 1, 20, 0);
+		else if (r_type == R_390_32)
+			rc = apply_rela_bits(loc, val, 0, 32, 0);
+		else if (r_type == R_390_64)
+			rc = apply_rela_bits(loc, val, 0, 64, 0);
+		break;
+	case R_390_PC16:	/* PC relative 16 bit.  */
+	case R_390_PC16DBL:	/* PC relative 16 bit shifted by 1.  */
+	case R_390_PC32DBL:	/* PC relative 32 bit shifted by 1.  */
+	case R_390_PC32:	/* PC relative 32 bit.  */
+	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);
+		else if (r_type == R_390_PC16DBL)
+			rc = apply_rela_bits(loc, val, 1, 16, 1);
+		else if (r_type == R_390_PC32DBL)
+			rc = apply_rela_bits(loc, val, 1, 32, 1);
+		else if (r_type == R_390_PC32)
+			rc = apply_rela_bits(loc, val, 1, 32, 0);
+		else if (r_type == R_390_PC64)
+			rc = apply_rela_bits(loc, val, 1, 64, 0);
+		break;
+	case R_390_GOT12:	/* 12 bit GOT offset.  */
+	case R_390_GOT16:	/* 16 bit GOT offset.  */
+	case R_390_GOT20:	/* 20 bit GOT offset.  */
+	case R_390_GOT32:	/* 32 bit GOT offset.  */
+	case R_390_GOT64:	/* 64 bit GOT offset.  */
+	case R_390_GOTENT:	/* 32 bit PC rel. to GOT entry shifted by 1. */
+	case R_390_GOTPLT12:	/* 12 bit offset to jump slot.	*/
+	case R_390_GOTPLT20:	/* 20 bit offset to jump slot.  */
+	case R_390_GOTPLT16:	/* 16 bit offset to jump slot.  */
+	case R_390_GOTPLT32:	/* 32 bit offset to jump slot.  */
+	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;
+
+			gotent = me->core_layout.base + me->arch.got_offset +
+				info->got_offset;
+			*gotent = val;
+			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);
+		else if (r_type == R_390_GOT16 ||
+			 r_type == R_390_GOTPLT16)
+			rc = apply_rela_bits(loc, val, 0, 16, 0);
+		else if (r_type == R_390_GOT20 ||
+			 r_type == R_390_GOTPLT20)
+			rc = apply_rela_bits(loc, val, 1, 20, 0);
+		else if (r_type == R_390_GOT32 ||
+			 r_type == R_390_GOTPLT32)
+			rc = apply_rela_bits(loc, val, 0, 32, 0);
+		else if (r_type == R_390_GOT64 ||
+			 r_type == R_390_GOTPLT64)
+			rc = apply_rela_bits(loc, val, 0, 64, 0);
+		else if (r_type == R_390_GOTENT ||
+			 r_type == R_390_GOTPLTENT) {
+			val += (Elf_Addr) me->core_layout.base - loc;
+			rc = apply_rela_bits(loc, val, 1, 32, 1);
+		}
+		break;
+	case R_390_PLT16DBL:	/* 16 bit PC rel. PLT shifted by 1.  */
+	case R_390_PLT32DBL:	/* 32 bit PC rel. PLT shifted by 1.  */
+	case R_390_PLT32:	/* 32 bit PC relative PLT address.  */
+	case R_390_PLT64:	/* 64 bit PC relative PLT address.  */
+	case R_390_PLTOFF16:	/* 16 bit offset from GOT to PLT. */
+	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->core_layout.base + me->arch.plt_offset +
+				info->plt_offset;
+			ip[0] = 0x0d10e310;	/* basr 1,0  */
+			ip[1] = 0x100a0004;	/* lg	1,10(1) */
+			if (IS_ENABLED(CONFIG_EXPOLINE) && !nospec_disable) {
+				unsigned int *ij;
+				ij = me->core_layout.base +
+					me->arch.plt_offset +
+					me->arch.plt_size - PLT_ENTRY_SIZE;
+				ip[2] = 0xa7f40000 +	/* j __jump_r1 */
+					(unsigned int)(u16)
+					(((unsigned long) ij - 8 -
+					  (unsigned long) ip) / 2);
+			} else {
+				ip[2] = 0x07f10000;	/* br %r1 */
+			}
+			ip[3] = (unsigned int) (val >> 32);
+			ip[4] = (unsigned int) val;
+			info->plt_initialized = 1;
+		}
+		if (r_type == R_390_PLTOFF16 ||
+		    r_type == R_390_PLTOFF32 ||
+		    r_type == R_390_PLTOFF64)
+			val = me->arch.plt_offset - me->arch.got_offset +
+				info->plt_offset + rela->r_addend;
+		else {
+			if (!((r_type == R_390_PLT16DBL &&
+			       val - loc + 0xffffUL < 0x1ffffeUL) ||
+			      (r_type == R_390_PLT32DBL &&
+			       val - loc + 0xffffffffULL < 0x1fffffffeULL)))
+				val = (Elf_Addr) me->core_layout.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);
+		else if (r_type == R_390_PLTOFF16)
+			rc = apply_rela_bits(loc, val, 0, 16, 0);
+		else if (r_type == R_390_PLT32DBL)
+			rc = apply_rela_bits(loc, val, 1, 32, 1);
+		else if (r_type == R_390_PLT32 ||
+			 r_type == R_390_PLTOFF32)
+			rc = apply_rela_bits(loc, val, 0, 32, 0);
+		else if (r_type == R_390_PLT64 ||
+			 r_type == R_390_PLTOFF64)
+			rc = apply_rela_bits(loc, val, 0, 64, 0);
+		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->core_layout.base + me->arch.got_offset);
+		if (r_type == R_390_GOTOFF16)
+			rc = apply_rela_bits(loc, val, 0, 16, 0);
+		else if (r_type == R_390_GOTOFF32)
+			rc = apply_rela_bits(loc, val, 0, 32, 0);
+		else if (r_type == R_390_GOTOFF64)
+			rc = apply_rela_bits(loc, val, 0, 64, 0);
+		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->core_layout.base + me->arch.got_offset +
+			rela->r_addend - loc;
+		if (r_type == R_390_GOTPC)
+			rc = apply_rela_bits(loc, val, 1, 32, 0);
+		else if (r_type == R_390_GOTPCDBL)
+			rc = apply_rela_bits(loc, val, 1, 32, 1);
+		break;
+	case R_390_COPY:
+	case R_390_GLOB_DAT:	/* Create GOT entry.  */
+	case R_390_JMP_SLOT:	/* Create PLT entry.  */
+	case R_390_RELATIVE:	/* Adjust by program base.  */
+		/* Only needed if we want to support loading of 
+		   modules linked with -shared. */
+		return -ENOEXEC;
+	default:
+		printk(KERN_ERR "module %s: unknown relocation: %u\n",
+		       me->name, r_type);
+		return -ENOEXEC;
+	}
+	if (rc) {
+		printk(KERN_ERR "module %s: relocation error for symbol %s "
+		       "(r_type %i, value 0x%lx)\n",
+		       me->name, strtab + symtab[r_sym].st_name,
+		       r_type, (unsigned long) val);
+		return rc;
+	}
+	return 0;
+}
+
+int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
+		       unsigned int symindex, unsigned int relsec,
+		       struct module *me)
+{
+	Elf_Addr base;
+	Elf_Sym *symtab;
+	Elf_Rela *rela;
+	unsigned long i, n;
+	int rc;
+
+	DEBUGP("Applying relocate section %u to %u\n",
+	       relsec, sechdrs[relsec].sh_info);
+	base = sechdrs[sechdrs[relsec].sh_info].sh_addr;
+	symtab = (Elf_Sym *) sechdrs[symindex].sh_addr;
+	rela = (Elf_Rela *) sechdrs[relsec].sh_addr;
+	n = sechdrs[relsec].sh_size / sizeof(Elf_Rela);
+
+	for (i = 0; i < n; i++, rela++) {
+		rc = apply_rela(rela, base, symtab, strtab, me);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+int module_finalize(const Elf_Ehdr *hdr,
+		    const Elf_Shdr *sechdrs,
+		    struct module *me)
+{
+	const Elf_Shdr *s;
+	char *secstrings, *secname;
+	void *aseg;
+
+	if (IS_ENABLED(CONFIG_EXPOLINE) &&
+	    !nospec_disable && me->arch.plt_size) {
+		unsigned int *ij;
+
+		ij = me->core_layout.base + me->arch.plt_offset +
+			me->arch.plt_size - PLT_ENTRY_SIZE;
+		if (test_facility(35)) {
+			ij[0] = 0xc6000000;	/* exrl	%r0,.+10	*/
+			ij[1] = 0x0005a7f4;	/* j	.		*/
+			ij[2] = 0x000007f1;	/* br	%r1		*/
+		} else {
+			ij[0] = 0x44000000 | (unsigned int)
+				offsetof(struct lowcore, br_r1_trampoline);
+			ij[1] = 0xa7f40000;	/* j	.		*/
+		}
+	}
+
+	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) &&
+		    (!strncmp(".s390_indirect", secname, 14)))
+			nospec_revert(aseg, aseg + s->sh_size);
+
+		if (IS_ENABLED(CONFIG_EXPOLINE) &&
+		    (!strncmp(".s390_return", secname, 12)))
+			nospec_revert(aseg, aseg + s->sh_size);
+	}
+
+	jump_label_apply_nops(me);
+	return 0;
+}