target/mips/mips-semi.c - third_party/qemu - Git at Google

 /*
  * Unified Hosting Interface syscalls.
  *
  * Copyright (c) 2015 Imagination Technologies
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */

 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "qemu/log.h"
 #include "exec/helper-proto.h"
 #include "exec/softmmu-semi.h"
 #include "exec/semihost.h"

 typedef enum UHIOp {
     UHI_exit = 1,
     UHI_open = 2,
     UHI_close = 3,
     UHI_read = 4,
     UHI_write = 5,
     UHI_lseek = 6,
     UHI_unlink = 7,
     UHI_fstat = 8,
     UHI_argc = 9,
     UHI_argnlen = 10,
     UHI_argn = 11,
     UHI_plog = 13,
     UHI_assert = 14,
     UHI_pread = 19,
     UHI_pwrite = 20,
     UHI_link = 22
 } UHIOp;

 typedef struct UHIStat {
     int16_t uhi_st_dev;
     uint16_t uhi_st_ino;
     uint32_t uhi_st_mode;
     uint16_t uhi_st_nlink;
     uint16_t uhi_st_uid;
     uint16_t uhi_st_gid;
     int16_t uhi_st_rdev;
     uint64_t uhi_st_size;
     uint64_t uhi_st_atime;
     uint64_t uhi_st_spare1;
     uint64_t uhi_st_mtime;
     uint64_t uhi_st_spare2;
     uint64_t uhi_st_ctime;
     uint64_t uhi_st_spare3;
     uint64_t uhi_st_blksize;
     uint64_t uhi_st_blocks;
     uint64_t uhi_st_spare4[2];
 } UHIStat;

 enum UHIOpenFlags {
     UHIOpen_RDONLY = 0x0,
     UHIOpen_WRONLY = 0x1,
     UHIOpen_RDWR   = 0x2,
     UHIOpen_APPEND = 0x8,
     UHIOpen_CREAT  = 0x200,
     UHIOpen_TRUNC  = 0x400,
     UHIOpen_EXCL   = 0x800
 };

 /* Errno values taken from asm-mips/errno.h */
 static uint16_t host_to_mips_errno[] = {
     [ENAMETOOLONG] = 78,
 #ifdef EOVERFLOW
     [EOVERFLOW]    = 79,
 #endif
 #ifdef ELOOP
     [ELOOP]        = 90,
 #endif
 };

 static int errno_mips(int err)
 {
     if (err < 0 || err >= ARRAY_SIZE(host_to_mips_errno)) {
         return EINVAL;
     } else if (host_to_mips_errno[err]) {
         return host_to_mips_errno[err];
     } else {
         return err;
     }
 }

 static int copy_stat_to_target(CPUMIPSState *env, const struct stat *src,
                                target_ulong vaddr)
 {
     hwaddr len = sizeof(struct UHIStat);
     UHIStat *dst = lock_user(VERIFY_WRITE, vaddr, len, 0);
     if (!dst) {
         errno = EFAULT;
         return -1;
     }

     dst->uhi_st_dev = tswap16(src->st_dev);
     dst->uhi_st_ino = tswap16(src->st_ino);
     dst->uhi_st_mode = tswap32(src->st_mode);
     dst->uhi_st_nlink = tswap16(src->st_nlink);
     dst->uhi_st_uid = tswap16(src->st_uid);
     dst->uhi_st_gid = tswap16(src->st_gid);
     dst->uhi_st_rdev = tswap16(src->st_rdev);
     dst->uhi_st_size = tswap64(src->st_size);
     dst->uhi_st_atime = tswap64(src->st_atime);
     dst->uhi_st_mtime = tswap64(src->st_mtime);
     dst->uhi_st_ctime = tswap64(src->st_ctime);
 #ifdef _WIN32
     dst->uhi_st_blksize = 0;
     dst->uhi_st_blocks = 0;
 #else
     dst->uhi_st_blksize = tswap64(src->st_blksize);
     dst->uhi_st_blocks = tswap64(src->st_blocks);
 #endif
     unlock_user(dst, vaddr, len);
     return 0;
 }

 static int get_open_flags(target_ulong target_flags)
 {
     int open_flags = 0;

     if (target_flags & UHIOpen_RDWR) {
         open_flags |= O_RDWR;
     } else if (target_flags & UHIOpen_WRONLY) {
         open_flags |= O_WRONLY;
     } else {
         open_flags |= O_RDONLY;
     }

     open_flags |= (target_flags & UHIOpen_APPEND) ? O_APPEND : 0;
     open_flags |= (target_flags & UHIOpen_CREAT)  ? O_CREAT  : 0;
     open_flags |= (target_flags & UHIOpen_TRUNC)  ? O_TRUNC  : 0;
     open_flags |= (target_flags & UHIOpen_EXCL)   ? O_EXCL   : 0;

     return open_flags;
 }

 static int write_to_file(CPUMIPSState *env, target_ulong fd, target_ulong vaddr,
                          target_ulong len, target_ulong offset)
 {
     int num_of_bytes;
     void *dst = lock_user(VERIFY_READ, vaddr, len, 1);
     if (!dst) {
         errno = EFAULT;
         return -1;
     }

     if (offset) {
 #ifdef _WIN32
         num_of_bytes = 0;
 #else
         num_of_bytes = pwrite(fd, dst, len, offset);
 #endif
     } else {
         num_of_bytes = write(fd, dst, len);
     }

     unlock_user(dst, vaddr, 0);
     return num_of_bytes;
 }

 static int read_from_file(CPUMIPSState *env, target_ulong fd,
                           target_ulong vaddr, target_ulong len,
                           target_ulong offset)
 {
     int num_of_bytes;
     void *dst = lock_user(VERIFY_WRITE, vaddr, len, 0);
     if (!dst) {
         errno = EFAULT;
         return -1;
     }

     if (offset) {
 #ifdef _WIN32
         num_of_bytes = 0;
 #else
         num_of_bytes = pread(fd, dst, len, offset);
 #endif
     } else {
         num_of_bytes = read(fd, dst, len);
     }

     unlock_user(dst, vaddr, len);
     return num_of_bytes;
 }

 static int copy_argn_to_target(CPUMIPSState *env, int arg_num,
                                target_ulong vaddr)
 {
     int strsize = strlen(semihosting_get_arg(arg_num)) + 1;
     char *dst = lock_user(VERIFY_WRITE, vaddr, strsize, 0);
     if (!dst) {
         return -1;
     }

     strcpy(dst, semihosting_get_arg(arg_num));

     unlock_user(dst, vaddr, strsize);
     return 0;
 }

 #define GET_TARGET_STRING(p, addr)              \
     do {                                        \
         p = lock_user_string(addr);             \
         if (!p) {                               \
             gpr[2] = -1;                        \
             gpr[3] = EFAULT;                    \
             goto uhi_done;                      \
         }                                       \
     } while (0)

 #define GET_TARGET_STRINGS_2(p, addr, p2, addr2)        \
     do {                                                \
         p = lock_user_string(addr);                     \
         if (!p) {                                       \
             gpr[2] = -1;                                \
             gpr[3] = EFAULT;                            \
             goto uhi_done;                              \
         }                                               \
         p2 = lock_user_string(addr2);                   \
         if (!p2) {                                      \
             unlock_user(p, addr, 0);                    \
             gpr[2] = -1;                                \
             gpr[3] = EFAULT;                            \
             goto uhi_done;                              \
         }                                               \
     } while (0)

 #define FREE_TARGET_STRING(p, gpr)              \
     do {                                        \
         unlock_user(p, gpr, 0);                 \
     } while (0)

 void helper_do_semihosting(CPUMIPSState *env)
 {
     target_ulong *gpr = env->active_tc.gpr;
     const UHIOp op = gpr[25];
     char *p, *p2;

     switch (op) {
     case UHI_exit:
         qemu_log("UHI(%d): exit(%d)\n", op, (int)gpr[4]);
         exit(gpr[4]);
     case UHI_open:
         GET_TARGET_STRING(p, gpr[4]);
         if (!strcmp("/dev/stdin", p)) {
             gpr[2] = 0;
         } else if (!strcmp("/dev/stdout", p)) {
             gpr[2] = 1;
         } else if (!strcmp("/dev/stderr", p)) {
             gpr[2] = 2;
         } else {
             gpr[2] = open(p, get_open_flags(gpr[5]), gpr[6]);
             gpr[3] = errno_mips(errno);
         }
         FREE_TARGET_STRING(p, gpr[4]);
         break;
     case UHI_close:
         if (gpr[4] < 3) {
             /* ignore closing stdin/stdout/stderr */
             gpr[2] = 0;
             goto uhi_done;
         }
         gpr[2] = close(gpr[4]);
         gpr[3] = errno_mips(errno);
         break;
     case UHI_read:
         gpr[2] = read_from_file(env, gpr[4], gpr[5], gpr[6], 0);
         gpr[3] = errno_mips(errno);
         break;
     case UHI_write:
         gpr[2] = write_to_file(env, gpr[4], gpr[5], gpr[6], 0);
         gpr[3] = errno_mips(errno);
         break;
     case UHI_lseek:
         gpr[2] = lseek(gpr[4], gpr[5], gpr[6]);
         gpr[3] = errno_mips(errno);
         break;
     case UHI_unlink:
         GET_TARGET_STRING(p, gpr[4]);
         gpr[2] = remove(p);
         gpr[3] = errno_mips(errno);
         FREE_TARGET_STRING(p, gpr[4]);
         break;
     case UHI_fstat:
         {
             struct stat sbuf;
             memset(&sbuf, 0, sizeof(sbuf));
             gpr[2] = fstat(gpr[4], &sbuf);
             gpr[3] = errno_mips(errno);
             if (gpr[2]) {
                 goto uhi_done;
             }
             gpr[2] = copy_stat_to_target(env, &sbuf, gpr[5]);
             gpr[3] = errno_mips(errno);
         }
         break;
     case UHI_argc:
         gpr[2] = semihosting_get_argc();
         break;
     case UHI_argnlen:
         if (gpr[4] >= semihosting_get_argc()) {
             gpr[2] = -1;
             goto uhi_done;
         }
         gpr[2] = strlen(semihosting_get_arg(gpr[4]));
         break;
     case UHI_argn:
         if (gpr[4] >= semihosting_get_argc()) {
             gpr[2] = -1;
             goto uhi_done;
         }
         gpr[2] = copy_argn_to_target(env, gpr[4], gpr[5]);
         break;
     case UHI_plog:
         GET_TARGET_STRING(p, gpr[4]);
         p2 = strstr(p, "%d");
         if (p2) {
             int char_num = p2 - p;
             char *buf = g_malloc(char_num + 1);
             strncpy(buf, p, char_num);
             buf[char_num] = '\0';
             gpr[2] = printf("%s%d%s", buf, (int)gpr[5], p2 + 2);
             g_free(buf);
         } else {
             gpr[2] = printf("%s", p);
         }
         FREE_TARGET_STRING(p, gpr[4]);
         break;
     case UHI_assert:
         GET_TARGET_STRINGS_2(p, gpr[4], p2, gpr[5]);
         printf("assertion '");
         printf("\"%s\"", p);
         printf("': file \"%s\", line %d\n", p2, (int)gpr[6]);
         FREE_TARGET_STRING(p2, gpr[5]);
         FREE_TARGET_STRING(p, gpr[4]);
         abort();
         break;
     case UHI_pread:
         gpr[2] = read_from_file(env, gpr[4], gpr[5], gpr[6], gpr[7]);
         gpr[3] = errno_mips(errno);
         break;
     case UHI_pwrite:
         gpr[2] = write_to_file(env, gpr[4], gpr[5], gpr[6], gpr[7]);
         gpr[3] = errno_mips(errno);
         break;
 #ifndef _WIN32
     case UHI_link:
         GET_TARGET_STRINGS_2(p, gpr[4], p2, gpr[5]);
         gpr[2] = link(p, p2);
         gpr[3] = errno_mips(errno);
         FREE_TARGET_STRING(p2, gpr[5]);
         FREE_TARGET_STRING(p, gpr[4]);
         break;
 #endif
     default:
         fprintf(stderr, "Unknown UHI operation %d\n", op);
         abort();
     }
 uhi_done:
     return;
 }
	/*
	* Unified Hosting Interface syscalls.
	*
	* Copyright (c) 2015 Imagination Technologies
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library 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
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include "qemu/osdep.h"
	#include "cpu.h"
	#include "qemu/log.h"
	#include "exec/helper-proto.h"
	#include "exec/softmmu-semi.h"
	#include "exec/semihost.h"

	typedef enum UHIOp {
	UHI_exit = 1,
	UHI_open = 2,
	UHI_close = 3,
	UHI_read = 4,
	UHI_write = 5,
	UHI_lseek = 6,
	UHI_unlink = 7,
	UHI_fstat = 8,
	UHI_argc = 9,
	UHI_argnlen = 10,
	UHI_argn = 11,
	UHI_plog = 13,
	UHI_assert = 14,
	UHI_pread = 19,
	UHI_pwrite = 20,
	UHI_link = 22
	} UHIOp;

	typedef struct UHIStat {
	int16_t uhi_st_dev;
	uint16_t uhi_st_ino;
	uint32_t uhi_st_mode;
	uint16_t uhi_st_nlink;
	uint16_t uhi_st_uid;
	uint16_t uhi_st_gid;
	int16_t uhi_st_rdev;
	uint64_t uhi_st_size;
	uint64_t uhi_st_atime;
	uint64_t uhi_st_spare1;
	uint64_t uhi_st_mtime;
	uint64_t uhi_st_spare2;
	uint64_t uhi_st_ctime;
	uint64_t uhi_st_spare3;
	uint64_t uhi_st_blksize;
	uint64_t uhi_st_blocks;
	uint64_t uhi_st_spare4[2];
	} UHIStat;

	enum UHIOpenFlags {
	UHIOpen_RDONLY = 0x0,
	UHIOpen_WRONLY = 0x1,
	UHIOpen_RDWR = 0x2,
	UHIOpen_APPEND = 0x8,
	UHIOpen_CREAT = 0x200,
	UHIOpen_TRUNC = 0x400,
	UHIOpen_EXCL = 0x800
	};

	/* Errno values taken from asm-mips/errno.h */
	static uint16_t host_to_mips_errno[] = {
	[ENAMETOOLONG] = 78,
	#ifdef EOVERFLOW
	[EOVERFLOW] = 79,
	#endif
	#ifdef ELOOP
	[ELOOP] = 90,
	#endif
	};

	static int errno_mips(int err)
	{
	if (err < 0 \|\| err >= ARRAY_SIZE(host_to_mips_errno)) {
	return EINVAL;
	} else if (host_to_mips_errno[err]) {
	return host_to_mips_errno[err];
	} else {
	return err;
	}
	}

	static int copy_stat_to_target(CPUMIPSState env, const struct stat src,
	target_ulong vaddr)
	{
	hwaddr len = sizeof(struct UHIStat);
	UHIStat *dst = lock_user(VERIFY_WRITE, vaddr, len, 0);
	if (!dst) {
	errno = EFAULT;
	return -1;
	}

	dst->uhi_st_dev = tswap16(src->st_dev);
	dst->uhi_st_ino = tswap16(src->st_ino);
	dst->uhi_st_mode = tswap32(src->st_mode);
	dst->uhi_st_nlink = tswap16(src->st_nlink);
	dst->uhi_st_uid = tswap16(src->st_uid);
	dst->uhi_st_gid = tswap16(src->st_gid);
	dst->uhi_st_rdev = tswap16(src->st_rdev);
	dst->uhi_st_size = tswap64(src->st_size);
	dst->uhi_st_atime = tswap64(src->st_atime);
	dst->uhi_st_mtime = tswap64(src->st_mtime);
	dst->uhi_st_ctime = tswap64(src->st_ctime);
	#ifdef _WIN32
	dst->uhi_st_blksize = 0;
	dst->uhi_st_blocks = 0;
	#else
	dst->uhi_st_blksize = tswap64(src->st_blksize);
	dst->uhi_st_blocks = tswap64(src->st_blocks);
	#endif
	unlock_user(dst, vaddr, len);
	return 0;
	}

	static int get_open_flags(target_ulong target_flags)
	{
	int open_flags = 0;

	if (target_flags & UHIOpen_RDWR) {
	open_flags \|= O_RDWR;
	} else if (target_flags & UHIOpen_WRONLY) {
	open_flags \|= O_WRONLY;
	} else {
	open_flags \|= O_RDONLY;
	}

	open_flags \|= (target_flags & UHIOpen_APPEND) ? O_APPEND : 0;
	open_flags \|= (target_flags & UHIOpen_CREAT) ? O_CREAT : 0;
	open_flags \|= (target_flags & UHIOpen_TRUNC) ? O_TRUNC : 0;
	open_flags \|= (target_flags & UHIOpen_EXCL) ? O_EXCL : 0;

	return open_flags;
	}

	static int write_to_file(CPUMIPSState *env, target_ulong fd, target_ulong vaddr,
	target_ulong len, target_ulong offset)
	{
	int num_of_bytes;
	void *dst = lock_user(VERIFY_READ, vaddr, len, 1);
	if (!dst) {
	errno = EFAULT;
	return -1;
	}

	if (offset) {
	#ifdef _WIN32
	num_of_bytes = 0;
	#else
	num_of_bytes = pwrite(fd, dst, len, offset);
	#endif
	} else {
	num_of_bytes = write(fd, dst, len);
	}

	unlock_user(dst, vaddr, 0);
	return num_of_bytes;
	}

	static int read_from_file(CPUMIPSState *env, target_ulong fd,
	target_ulong vaddr, target_ulong len,
	target_ulong offset)
	{
	int num_of_bytes;
	void *dst = lock_user(VERIFY_WRITE, vaddr, len, 0);
	if (!dst) {
	errno = EFAULT;
	return -1;
	}

	if (offset) {
	#ifdef _WIN32
	num_of_bytes = 0;
	#else
	num_of_bytes = pread(fd, dst, len, offset);
	#endif
	} else {
	num_of_bytes = read(fd, dst, len);
	}

	unlock_user(dst, vaddr, len);
	return num_of_bytes;
	}

	static int copy_argn_to_target(CPUMIPSState *env, int arg_num,
	target_ulong vaddr)
	{
	int strsize = strlen(semihosting_get_arg(arg_num)) + 1;
	char *dst = lock_user(VERIFY_WRITE, vaddr, strsize, 0);
	if (!dst) {
	return -1;
	}

	strcpy(dst, semihosting_get_arg(arg_num));

	unlock_user(dst, vaddr, strsize);
	return 0;
	}

	#define GET_TARGET_STRING(p, addr) \
	do { \
	p = lock_user_string(addr); \
	if (!p) { \
	gpr[2] = -1; \
	gpr[3] = EFAULT; \
	goto uhi_done; \
	} \
	} while (0)

	#define GET_TARGET_STRINGS_2(p, addr, p2, addr2) \
	do { \
	p = lock_user_string(addr); \
	if (!p) { \
	gpr[2] = -1; \
	gpr[3] = EFAULT; \
	goto uhi_done; \
	} \
	p2 = lock_user_string(addr2); \
	if (!p2) { \
	unlock_user(p, addr, 0); \
	gpr[2] = -1; \
	gpr[3] = EFAULT; \
	goto uhi_done; \
	} \
	} while (0)

	#define FREE_TARGET_STRING(p, gpr) \
	do { \
	unlock_user(p, gpr, 0); \
	} while (0)

	void helper_do_semihosting(CPUMIPSState *env)
	{
	target_ulong *gpr = env->active_tc.gpr;
	const UHIOp op = gpr[25];
	char p, p2;

	switch (op) {
	case UHI_exit:
	qemu_log("UHI(%d): exit(%d)\n", op, (int)gpr[4]);
	exit(gpr[4]);
	case UHI_open:
	GET_TARGET_STRING(p, gpr[4]);
	if (!strcmp("/dev/stdin", p)) {
	gpr[2] = 0;
	} else if (!strcmp("/dev/stdout", p)) {
	gpr[2] = 1;
	} else if (!strcmp("/dev/stderr", p)) {
	gpr[2] = 2;
	} else {
	gpr[2] = open(p, get_open_flags(gpr[5]), gpr[6]);
	gpr[3] = errno_mips(errno);
	}
	FREE_TARGET_STRING(p, gpr[4]);
	break;
	case UHI_close:
	if (gpr[4] < 3) {
	/* ignore closing stdin/stdout/stderr */
	gpr[2] = 0;
	goto uhi_done;
	}
	gpr[2] = close(gpr[4]);
	gpr[3] = errno_mips(errno);
	break;
	case UHI_read:
	gpr[2] = read_from_file(env, gpr[4], gpr[5], gpr[6], 0);
	gpr[3] = errno_mips(errno);
	break;
	case UHI_write:
	gpr[2] = write_to_file(env, gpr[4], gpr[5], gpr[6], 0);
	gpr[3] = errno_mips(errno);
	break;
	case UHI_lseek:
	gpr[2] = lseek(gpr[4], gpr[5], gpr[6]);
	gpr[3] = errno_mips(errno);
	break;
	case UHI_unlink:
	GET_TARGET_STRING(p, gpr[4]);
	gpr[2] = remove(p);
	gpr[3] = errno_mips(errno);
	FREE_TARGET_STRING(p, gpr[4]);
	break;
	case UHI_fstat:
	{
	struct stat sbuf;
	memset(&sbuf, 0, sizeof(sbuf));
	gpr[2] = fstat(gpr[4], &sbuf);
	gpr[3] = errno_mips(errno);
	if (gpr[2]) {
	goto uhi_done;
	}
	gpr[2] = copy_stat_to_target(env, &sbuf, gpr[5]);
	gpr[3] = errno_mips(errno);
	}
	break;
	case UHI_argc:
	gpr[2] = semihosting_get_argc();
	break;
	case UHI_argnlen:
	if (gpr[4] >= semihosting_get_argc()) {
	gpr[2] = -1;
	goto uhi_done;
	}
	gpr[2] = strlen(semihosting_get_arg(gpr[4]));
	break;
	case UHI_argn:
	if (gpr[4] >= semihosting_get_argc()) {
	gpr[2] = -1;
	goto uhi_done;
	}
	gpr[2] = copy_argn_to_target(env, gpr[4], gpr[5]);
	break;
	case UHI_plog:
	GET_TARGET_STRING(p, gpr[4]);
	p2 = strstr(p, "%d");
	if (p2) {
	int char_num = p2 - p;
	char *buf = g_malloc(char_num + 1);
	strncpy(buf, p, char_num);
	buf[char_num] = '\0';
	gpr[2] = printf("%s%d%s", buf, (int)gpr[5], p2 + 2);
	g_free(buf);
	} else {
	gpr[2] = printf("%s", p);
	}
	FREE_TARGET_STRING(p, gpr[4]);
	break;
	case UHI_assert:
	GET_TARGET_STRINGS_2(p, gpr[4], p2, gpr[5]);
	printf("assertion '");
	printf("\"%s\"", p);
	printf("': file \"%s\", line %d\n", p2, (int)gpr[6]);
	FREE_TARGET_STRING(p2, gpr[5]);
	FREE_TARGET_STRING(p, gpr[4]);
	abort();
	break;
	case UHI_pread:
	gpr[2] = read_from_file(env, gpr[4], gpr[5], gpr[6], gpr[7]);
	gpr[3] = errno_mips(errno);
	break;
	case UHI_pwrite:
	gpr[2] = write_to_file(env, gpr[4], gpr[5], gpr[6], gpr[7]);
	gpr[3] = errno_mips(errno);
	break;
	#ifndef _WIN32
	case UHI_link:
	GET_TARGET_STRINGS_2(p, gpr[4], p2, gpr[5]);
	gpr[2] = link(p, p2);
	gpr[3] = errno_mips(errno);
	FREE_TARGET_STRING(p2, gpr[5]);
	FREE_TARGET_STRING(p, gpr[4]);
	break;
	#endif
	default:
	fprintf(stderr, "Unknown UHI operation %d\n", op);
	abort();
	}
	uhi_done:
	return;
	}