diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/x86/Makefile | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/x86/entry_from_vm86.c | 114 |
2 files changed, 118 insertions, 2 deletions
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 5bdb781163d1..9b0d8baf2934 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -5,8 +5,10 @@ include ../lib.mk .PHONY: all all_32 all_64 warn_32bit_failure clean TARGETS_C_BOTHBITS := sigreturn single_step_syscall +TARGETS_C_32BIT_ONLY := entry_from_vm86 -BINARIES_32 := $(TARGETS_C_BOTHBITS:%=%_32) +TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) +BINARIES_32 := $(TARGETS_C_32BIT_ALL:%=%_32) BINARIES_64 := $(TARGETS_C_BOTHBITS:%=%_64) CFLAGS := -O2 -g -std=gnu99 -pthread -Wall @@ -32,7 +34,7 @@ all_64: $(BINARIES_64) clean: $(RM) $(BINARIES_32) $(BINARIES_64) -$(TARGETS_C_BOTHBITS:%=%_32): %_32: %.c +$(TARGETS_C_32BIT_ALL:%=%_32): %_32: %.c $(CC) -m32 -o $@ $(CFLAGS) $(EXTRA_CFLAGS) $^ -lrt -ldl $(TARGETS_C_BOTHBITS:%=%_64): %_64: %.c diff --git a/tools/testing/selftests/x86/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c new file mode 100644 index 000000000000..5c38a187677b --- /dev/null +++ b/tools/testing/selftests/x86/entry_from_vm86.c @@ -0,0 +1,114 @@ +/* + * entry_from_vm86.c - tests kernel entries from vm86 mode + * Copyright (c) 2014-2015 Andrew Lutomirski + * + * This exercises a few paths that need to special-case vm86 mode. + * + * GPL v2. + */ + +#define _GNU_SOURCE + +#include <assert.h> +#include <stdlib.h> +#include <sys/syscall.h> +#include <sys/signal.h> +#include <sys/ucontext.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <inttypes.h> +#include <sys/mman.h> +#include <err.h> +#include <stddef.h> +#include <stdbool.h> +#include <errno.h> +#include <sys/vm86.h> + +static unsigned long load_addr = 0x10000; +static int nerrs = 0; + +asm ( + ".pushsection .rodata\n\t" + ".type vmcode_bound, @object\n\t" + "vmcode:\n\t" + "vmcode_bound:\n\t" + ".code16\n\t" + "bound %ax, (2048)\n\t" + "int3\n\t" + "vmcode_sysenter:\n\t" + "sysenter\n\t" + ".size vmcode, . - vmcode\n\t" + "end_vmcode:\n\t" + ".code32\n\t" + ".popsection" + ); + +extern unsigned char vmcode[], end_vmcode[]; +extern unsigned char vmcode_bound[], vmcode_sysenter[]; + +static void do_test(struct vm86plus_struct *v86, unsigned long eip, + const char *text) +{ + long ret; + + printf("[RUN]\t%s from vm86 mode\n", text); + v86->regs.eip = eip; + ret = vm86(VM86_ENTER, v86); + + if (ret == -1 && errno == ENOSYS) { + printf("[SKIP]\tvm86 not supported\n"); + return; + } + + if (VM86_TYPE(ret) == VM86_INTx) { + char trapname[32]; + int trapno = VM86_ARG(ret); + if (trapno == 13) + strcpy(trapname, "GP"); + else if (trapno == 5) + strcpy(trapname, "BR"); + else if (trapno == 14) + strcpy(trapname, "PF"); + else + sprintf(trapname, "%d", trapno); + + printf("[OK]\tExited vm86 mode due to #%s\n", trapname); + } else if (VM86_TYPE(ret) == VM86_UNKNOWN) { + printf("[OK]\tExited vm86 mode due to unhandled GP fault\n"); + } else { + printf("[OK]\tExited vm86 mode due to type %ld, arg %ld\n", + VM86_TYPE(ret), VM86_ARG(ret)); + } +} + +int main(void) +{ + struct vm86plus_struct v86; + unsigned char *addr = mmap((void *)load_addr, 4096, + PROT_READ | PROT_WRITE | PROT_EXEC, + MAP_ANONYMOUS | MAP_PRIVATE, -1,0); + if (addr != (unsigned char *)load_addr) + err(1, "mmap"); + + memcpy(addr, vmcode, end_vmcode - vmcode); + addr[2048] = 2; + addr[2050] = 3; + + memset(&v86, 0, sizeof(v86)); + + v86.regs.cs = load_addr / 16; + v86.regs.ss = load_addr / 16; + v86.regs.ds = load_addr / 16; + v86.regs.es = load_addr / 16; + + assert((v86.regs.cs & 3) == 0); /* Looks like RPL = 0 */ + + /* #BR -- should deliver SIG??? */ + do_test(&v86, vmcode_bound - vmcode, "#BR"); + + /* SYSENTER -- should cause #GP or #UD depending on CPU */ + do_test(&v86, vmcode_sysenter - vmcode, "SYSENTER"); + + return (nerrs == 0 ? 0 : 1); +} |