Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 401 insertions, 0 deletions

diff --git a/arch/x86/math-emu/get_address.c b/arch/x86/math-emu/get_address.c
new file mode 100644
index 000000000..b82ca14ba
--- /dev/null
+++ b/arch/x86/math-emu/get_address.c
@@ -0,0 +1,401 @@
+// SPDX-License-Identifier: GPL-2.0
+/*---------------------------------------------------------------------------+
+ |  get_address.c                                                            |
+ |                                                                           |
+ | Get the effective address from an FPU instruction.                        |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1997                                         |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail   billm@suburbia.net             |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | Note:                                                                     |
+ |    The file contains code which accesses user memory.                     |
+ |    Emulator static data may change when user memory is accessed, due to   |
+ |    other processes using the emulator while swapping is in progress.      |
+ +---------------------------------------------------------------------------*/
+
+#include <linux/stddef.h>
+
+#include <linux/uaccess.h>
+#include <asm/vm86.h>
+
+#include "fpu_system.h"
+#include "exception.h"
+#include "fpu_emu.h"
+
+#define FPU_WRITE_BIT 0x10
+
+static int reg_offset[] = {
+	offsetof(struct pt_regs, ax),
+	offsetof(struct pt_regs, cx),
+	offsetof(struct pt_regs, dx),
+	offsetof(struct pt_regs, bx),
+	offsetof(struct pt_regs, sp),
+	offsetof(struct pt_regs, bp),
+	offsetof(struct pt_regs, si),
+	offsetof(struct pt_regs, di)
+};
+
+#define REG_(x) (*(long *)(reg_offset[(x)] + (u_char *)FPU_info->regs))
+
+static int reg_offset_vm86[] = {
+	offsetof(struct pt_regs, cs),
+	offsetof(struct kernel_vm86_regs, ds),
+	offsetof(struct kernel_vm86_regs, es),
+	offsetof(struct kernel_vm86_regs, fs),
+	offsetof(struct kernel_vm86_regs, gs),
+	offsetof(struct pt_regs, ss),
+	offsetof(struct kernel_vm86_regs, ds)
+};
+
+#define VM86_REG_(x) (*(unsigned short *) \
+		(reg_offset_vm86[((unsigned)x)] + (u_char *)FPU_info->regs))
+
+static int reg_offset_pm[] = {
+	offsetof(struct pt_regs, cs),
+	offsetof(struct pt_regs, ds),
+	offsetof(struct pt_regs, es),
+	offsetof(struct pt_regs, fs),
+	offsetof(struct pt_regs, ds),	/* dummy, not saved on stack */
+	offsetof(struct pt_regs, ss),
+	offsetof(struct pt_regs, ds)
+};
+
+#define PM_REG_(x) (*(unsigned short *) \
+		(reg_offset_pm[((unsigned)x)] + (u_char *)FPU_info->regs))
+
+/* Decode the SIB byte. This function assumes mod != 0 */
+static int sib(int mod, unsigned long *fpu_eip)
+{
+	u_char ss, index, base;
+	long offset;
+
+	RE_ENTRANT_CHECK_OFF;
+	FPU_code_access_ok(1);
+	FPU_get_user(base, (u_char __user *) (*fpu_eip));	/* The SIB byte */
+	RE_ENTRANT_CHECK_ON;
+	(*fpu_eip)++;
+	ss = base >> 6;
+	index = (base >> 3) & 7;
+	base &= 7;
+
+	if ((mod == 0) && (base == 5))
+		offset = 0;	/* No base register */
+	else
+		offset = REG_(base);
+
+	if (index == 4) {
+		/* No index register */
+		/* A non-zero ss is illegal */
+		if (ss)
+			EXCEPTION(EX_Invalid);
+	} else {
+		offset += (REG_(index)) << ss;
+	}
+
+	if (mod == 1) {
+		/* 8 bit signed displacement */
+		long displacement;
+		RE_ENTRANT_CHECK_OFF;
+		FPU_code_access_ok(1);
+		FPU_get_user(displacement, (signed char __user *)(*fpu_eip));
+		offset += displacement;
+		RE_ENTRANT_CHECK_ON;
+		(*fpu_eip)++;
+	} else if (mod == 2 || base == 5) {	/* The second condition also has mod==0 */
+		/* 32 bit displacement */
+		long displacement;
+		RE_ENTRANT_CHECK_OFF;
+		FPU_code_access_ok(4);
+		FPU_get_user(displacement, (long __user *)(*fpu_eip));
+		offset += displacement;
+		RE_ENTRANT_CHECK_ON;
+		(*fpu_eip) += 4;
+	}
+
+	return offset;
+}
+
+static unsigned long vm86_segment(u_char segment, struct address *addr)
+{
+	segment--;
+#ifdef PARANOID
+	if (segment > PREFIX_SS_) {
+		EXCEPTION(EX_INTERNAL | 0x130);
+		math_abort(FPU_info, SIGSEGV);
+	}
+#endif /* PARANOID */
+	addr->selector = VM86_REG_(segment);
+	return (unsigned long)VM86_REG_(segment) << 4;
+}
+
+/* This should work for 16 and 32 bit protected mode. */
+static long pm_address(u_char FPU_modrm, u_char segment,
+		       struct address *addr, long offset)
+{
+	struct desc_struct descriptor;
+	unsigned long base_address, limit, address, seg_top;
+
+	segment--;
+
+#ifdef PARANOID
+	/* segment is unsigned, so this also detects if segment was 0: */
+	if (segment > PREFIX_SS_) {
+		EXCEPTION(EX_INTERNAL | 0x132);
+		math_abort(FPU_info, SIGSEGV);
+	}
+#endif /* PARANOID */
+
+	switch (segment) {
+	case PREFIX_GS_ - 1:
+		/* user gs handling can be lazy, use special accessors */
+		addr->selector = get_user_gs(FPU_info->regs);
+		break;
+	default:
+		addr->selector = PM_REG_(segment);
+	}
+
+	descriptor = FPU_get_ldt_descriptor(addr->selector);
+	base_address = seg_get_base(&descriptor);
+	address = base_address + offset;
+	limit = seg_get_limit(&descriptor) + 1;
+	limit *= seg_get_granularity(&descriptor);
+	limit += base_address - 1;
+	if (limit < base_address)
+		limit = 0xffffffff;
+
+	if (seg_expands_down(&descriptor)) {
+		if (descriptor.g) {
+			seg_top = 0xffffffff;
+		} else {
+			seg_top = base_address + (1 << 20);
+			if (seg_top < base_address)
+				seg_top = 0xffffffff;
+		}
+		access_limit =
+		    (address <= limit) || (address >= seg_top) ? 0 :
+		    ((seg_top - address) >= 255 ? 255 : seg_top - address);
+	} else {
+		access_limit =
+		    (address > limit) || (address < base_address) ? 0 :
+		    ((limit - address) >= 254 ? 255 : limit - address + 1);
+	}
+	if (seg_execute_only(&descriptor) ||
+	    (!seg_writable(&descriptor) && (FPU_modrm & FPU_WRITE_BIT))) {
+		access_limit = 0;
+	}
+	return address;
+}
+
+/*
+       MOD R/M byte:  MOD == 3 has a special use for the FPU
+                      SIB byte used iff R/M = 100b
+
+       7   6   5   4   3   2   1   0
+       .....   .........   .........
+        MOD    OPCODE(2)     R/M
+
+       SIB byte
+
+       7   6   5   4   3   2   1   0
+       .....   .........   .........
+        SS      INDEX        BASE
+
+*/
+
+void __user *FPU_get_address(u_char FPU_modrm, unsigned long *fpu_eip,
+			     struct address *addr, fpu_addr_modes addr_modes)
+{
+	u_char mod;
+	unsigned rm = FPU_modrm & 7;
+	long *cpu_reg_ptr;
+	int address = 0;	/* Initialized just to stop compiler warnings. */
+
+	/* Memory accessed via the cs selector is write protected
+	   in `non-segmented' 32 bit protected mode. */
+	if (!addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT)
+	    && (addr_modes.override.segment == PREFIX_CS_)) {
+		math_abort(FPU_info, SIGSEGV);
+	}
+
+	addr->selector = FPU_DS;	/* Default, for 32 bit non-segmented mode. */
+
+	mod = (FPU_modrm >> 6) & 3;
+
+	if (rm == 4 && mod != 3) {
+		address = sib(mod, fpu_eip);
+	} else {
+		cpu_reg_ptr = &REG_(rm);
+		switch (mod) {
+		case 0:
+			if (rm == 5) {
+				/* Special case: disp32 */
+				RE_ENTRANT_CHECK_OFF;
+				FPU_code_access_ok(4);
+				FPU_get_user(address,
+					     (unsigned long __user
+					      *)(*fpu_eip));
+				(*fpu_eip) += 4;
+				RE_ENTRANT_CHECK_ON;
+				addr->offset = address;
+				return (void __user *)address;
+			} else {
+				address = *cpu_reg_ptr;	/* Just return the contents
+							   of the cpu register */
+				addr->offset = address;
+				return (void __user *)address;
+			}
+		case 1:
+			/* 8 bit signed displacement */
+			RE_ENTRANT_CHECK_OFF;
+			FPU_code_access_ok(1);
+			FPU_get_user(address, (signed char __user *)(*fpu_eip));
+			RE_ENTRANT_CHECK_ON;
+			(*fpu_eip)++;
+			break;
+		case 2:
+			/* 32 bit displacement */
+			RE_ENTRANT_CHECK_OFF;
+			FPU_code_access_ok(4);
+			FPU_get_user(address, (long __user *)(*fpu_eip));
+			(*fpu_eip) += 4;
+			RE_ENTRANT_CHECK_ON;
+			break;
+		case 3:
+			/* Not legal for the FPU */
+			EXCEPTION(EX_Invalid);
+		}
+		address += *cpu_reg_ptr;
+	}
+
+	addr->offset = address;
+
+	switch (addr_modes.default_mode) {
+	case 0:
+		break;
+	case VM86:
+		address += vm86_segment(addr_modes.override.segment, addr);
+		break;
+	case PM16:
+	case SEG32:
+		address = pm_address(FPU_modrm, addr_modes.override.segment,
+				     addr, address);
+		break;
+	default:
+		EXCEPTION(EX_INTERNAL | 0x133);
+	}
+
+	return (void __user *)address;
+}
+
+void __user *FPU_get_address_16(u_char FPU_modrm, unsigned long *fpu_eip,
+				struct address *addr, fpu_addr_modes addr_modes)
+{
+	u_char mod;
+	unsigned rm = FPU_modrm & 7;
+	int address = 0;	/* Default used for mod == 0 */
+
+	/* Memory accessed via the cs selector is write protected
+	   in `non-segmented' 32 bit protected mode. */
+	if (!addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT)
+	    && (addr_modes.override.segment == PREFIX_CS_)) {
+		math_abort(FPU_info, SIGSEGV);
+	}
+
+	addr->selector = FPU_DS;	/* Default, for 32 bit non-segmented mode. */
+
+	mod = (FPU_modrm >> 6) & 3;
+
+	switch (mod) {
+	case 0:
+		if (rm == 6) {
+			/* Special case: disp16 */
+			RE_ENTRANT_CHECK_OFF;
+			FPU_code_access_ok(2);
+			FPU_get_user(address,
+				     (unsigned short __user *)(*fpu_eip));
+			(*fpu_eip) += 2;
+			RE_ENTRANT_CHECK_ON;
+			goto add_segment;
+		}
+		break;
+	case 1:
+		/* 8 bit signed displacement */
+		RE_ENTRANT_CHECK_OFF;
+		FPU_code_access_ok(1);
+		FPU_get_user(address, (signed char __user *)(*fpu_eip));
+		RE_ENTRANT_CHECK_ON;
+		(*fpu_eip)++;
+		break;
+	case 2:
+		/* 16 bit displacement */
+		RE_ENTRANT_CHECK_OFF;
+		FPU_code_access_ok(2);
+		FPU_get_user(address, (unsigned short __user *)(*fpu_eip));
+		(*fpu_eip) += 2;
+		RE_ENTRANT_CHECK_ON;
+		break;
+	case 3:
+		/* Not legal for the FPU */
+		EXCEPTION(EX_Invalid);
+		break;
+	}
+	switch (rm) {
+	case 0:
+		address += FPU_info->regs->bx + FPU_info->regs->si;
+		break;
+	case 1:
+		address += FPU_info->regs->bx + FPU_info->regs->di;
+		break;
+	case 2:
+		address += FPU_info->regs->bp + FPU_info->regs->si;
+		if (addr_modes.override.segment == PREFIX_DEFAULT)
+			addr_modes.override.segment = PREFIX_SS_;
+		break;
+	case 3:
+		address += FPU_info->regs->bp + FPU_info->regs->di;
+		if (addr_modes.override.segment == PREFIX_DEFAULT)
+			addr_modes.override.segment = PREFIX_SS_;
+		break;
+	case 4:
+		address += FPU_info->regs->si;
+		break;
+	case 5:
+		address += FPU_info->regs->di;
+		break;
+	case 6:
+		address += FPU_info->regs->bp;
+		if (addr_modes.override.segment == PREFIX_DEFAULT)
+			addr_modes.override.segment = PREFIX_SS_;
+		break;
+	case 7:
+		address += FPU_info->regs->bx;
+		break;
+	}
+
+      add_segment:
+	address &= 0xffff;
+
+	addr->offset = address;
+
+	switch (addr_modes.default_mode) {
+	case 0:
+		break;
+	case VM86:
+		address += vm86_segment(addr_modes.override.segment, addr);
+		break;
+	case PM16:
+	case SEG32:
+		address = pm_address(FPU_modrm, addr_modes.override.segment,
+				     addr, address);
+		break;
+	default:
+		EXCEPTION(EX_INTERNAL | 0x131);
+	}
+
+	return (void __user *)address;
+}