mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
ff50265856
qemu/semihosting/arm-compat-semi.c
Richard Henderson 60f1c8017a linux-user: Clean up arg_start/arg_end confusion 
We had two sets of variables: arg_start/arg_end, and
arg_strings/env_strings.  In linuxload.c, we set the
first pair to the bounds of the argv strings, but in
elfload.c, we set the first pair to the bounds of the
argv pointers and the second pair to the bounds of
the argv strings.

Remove arg_start/arg_end, replacing them with the standard
argc/argv/envc/envp values.  Retain arg_strings/env_strings
with the meaning we were using in elfload.c.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/714
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220427025129.160184-1-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-05-23 08:15:19 +02:00

1293 lines
37 KiB
C
Raw Blame History

/*
* Semihosting support for systems modeled on the Arm "Angel"
* semihosting syscalls design. This includes Arm and RISC-V processors
*
* Copyright (c) 2005, 2007 CodeSourcery.
* Copyright (c) 2019 Linaro
* Written by Paul Brook.
*
* Copyright © 2020 by Keith Packard <keithp@keithp.com>
* Adapted for systems other than ARM, including RISC-V, by Keith Packard
*
* 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, see <http://www.gnu.org/licenses/>.
*
* ARM Semihosting is documented in:
* Semihosting for AArch32 and AArch64 Release 2.0
* https://static.docs.arm.com/100863/0200/semihosting.pdf
*
* RISC-V Semihosting is documented in:
* RISC-V Semihosting
* https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc
*/
#include "qemu/osdep.h"
#include "semihosting/semihost.h"
#include "semihosting/console.h"
#include "semihosting/common-semi.h"
#include "qemu/timer.h"
#include "exec/gdbstub.h"
#ifdef CONFIG_USER_ONLY
#include "qemu.h"
#define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024)
#else
#include "qemu/cutils.h"
#include "hw/loader.h"
#ifdef TARGET_ARM
#include "hw/arm/boot.h"
#endif
#include "hw/boards.h"
#endif
#define TARGET_SYS_OPEN 0x01
#define TARGET_SYS_CLOSE 0x02
#define TARGET_SYS_WRITEC 0x03
#define TARGET_SYS_WRITE0 0x04
#define TARGET_SYS_WRITE 0x05
#define TARGET_SYS_READ 0x06
#define TARGET_SYS_READC 0x07
#define TARGET_SYS_ISERROR 0x08
#define TARGET_SYS_ISTTY 0x09
#define TARGET_SYS_SEEK 0x0a
#define TARGET_SYS_FLEN 0x0c
#define TARGET_SYS_TMPNAM 0x0d
#define TARGET_SYS_REMOVE 0x0e
#define TARGET_SYS_RENAME 0x0f
#define TARGET_SYS_CLOCK 0x10
#define TARGET_SYS_TIME 0x11
#define TARGET_SYS_SYSTEM 0x12
#define TARGET_SYS_ERRNO 0x13
#define TARGET_SYS_GET_CMDLINE 0x15
#define TARGET_SYS_HEAPINFO 0x16
#define TARGET_SYS_EXIT 0x18
#define TARGET_SYS_SYNCCACHE 0x19
#define TARGET_SYS_EXIT_EXTENDED 0x20
#define TARGET_SYS_ELAPSED 0x30
#define TARGET_SYS_TICKFREQ 0x31
/* ADP_Stopped_ApplicationExit is used for exit(0),
* anything else is implemented as exit(1) */
#define ADP_Stopped_ApplicationExit (0x20026)
#ifndef O_BINARY
#define O_BINARY 0
#endif
#define GDB_O_RDONLY 0x000
#define GDB_O_WRONLY 0x001
#define GDB_O_RDWR 0x002
#define GDB_O_APPEND 0x008
#define GDB_O_CREAT 0x200
#define GDB_O_TRUNC 0x400
#define GDB_O_BINARY 0
static int gdb_open_modeflags[12] = {
GDB_O_RDONLY,
GDB_O_RDONLY | GDB_O_BINARY,
GDB_O_RDWR,
GDB_O_RDWR | GDB_O_BINARY,
GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,
GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,
GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,
GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,
GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY,
GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,
GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY
};
static int open_modeflags[12] = {
O_RDONLY,
O_RDONLY | O_BINARY,
O_RDWR,
O_RDWR | O_BINARY,
O_WRONLY | O_CREAT | O_TRUNC,
O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
O_RDWR | O_CREAT | O_TRUNC,
O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
O_WRONLY | O_CREAT | O_APPEND,
O_WRONLY | O_CREAT | O_APPEND | O_BINARY,
O_RDWR | O_CREAT | O_APPEND,
O_RDWR | O_CREAT | O_APPEND | O_BINARY
};
typedef enum GuestFDType {
GuestFDUnused = 0,
GuestFDHost = 1,
GuestFDGDB = 2,
GuestFDFeatureFile = 3,
} GuestFDType;
/*
* Guest file descriptors are integer indexes into an array of
* these structures (we will dynamically resize as necessary).
*/
typedef struct GuestFD {
GuestFDType type;
union {
int hostfd;
target_ulong featurefile_offset;
};
} GuestFD;
static GArray *guestfd_array;
#ifndef CONFIG_USER_ONLY
/**
* common_semi_find_bases: find information about ram and heap base
*
* This function attempts to provide meaningful numbers for RAM and
* HEAP base addresses. The rambase is simply the lowest addressable
* RAM position. For the heapbase we ask the loader to scan the
* address space and the largest available gap by querying the "ROM"
* regions.
*
* Returns: a structure with the numbers we need.
*/
typedef struct LayoutInfo {
target_ulong rambase;
size_t ramsize;
hwaddr heapbase;
hwaddr heaplimit;
} LayoutInfo;
static bool find_ram_cb(Int128 start, Int128 len, const MemoryRegion *mr,
hwaddr offset_in_region, void *opaque)
{
LayoutInfo *info = (LayoutInfo *) opaque;
uint64_t size = int128_get64(len);
if (!mr->ram || mr->readonly) {
return false;
}
if (size > info->ramsize) {
info->rambase = int128_get64(start);
info->ramsize = size;
}
/* search exhaustively for largest RAM */
return false;
}
static LayoutInfo common_semi_find_bases(CPUState *cs)
{
FlatView *fv;
LayoutInfo info = { 0, 0, 0, 0 };
RCU_READ_LOCK_GUARD();
fv = address_space_to_flatview(cs->as);
flatview_for_each_range(fv, find_ram_cb, &info);
/*
* If we have found the RAM lets iterate through the ROM blobs to
* work out the best place for the remainder of RAM and split it
* equally between stack and heap.
*/
if (info.rambase || info.ramsize > 0) {
RomGap gap = rom_find_largest_gap_between(info.rambase, info.ramsize);
info.heapbase = gap.base;
info.heaplimit = gap.base + gap.size;
}
return info;
}
#endif
#ifdef TARGET_ARM
static inline target_ulong
common_semi_arg(CPUState *cs, int argno)
{
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
if (is_a64(env)) {
return env->xregs[argno];
} else {
return env->regs[argno];
}
}
static inline void
common_semi_set_ret(CPUState *cs, target_ulong ret)
{
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
if (is_a64(env)) {
env->xregs[0] = ret;
} else {
env->regs[0] = ret;
}
}
static inline bool
common_semi_sys_exit_extended(CPUState *cs, int nr)
{
return (nr == TARGET_SYS_EXIT_EXTENDED || is_a64(cs->env_ptr));
}
#endif /* TARGET_ARM */
#ifdef TARGET_RISCV
static inline target_ulong
common_semi_arg(CPUState *cs, int argno)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
return env->gpr[xA0 + argno];
}
static inline void
common_semi_set_ret(CPUState *cs, target_ulong ret)
{
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
env->gpr[xA0] = ret;
}
static inline bool
common_semi_sys_exit_extended(CPUState *cs, int nr)
{
return (nr == TARGET_SYS_EXIT_EXTENDED || sizeof(target_ulong) == 8);
}
#endif
/*
* Allocate a new guest file descriptor and return it; if we
* couldn't allocate a new fd then return -1.
* This is a fairly simplistic implementation because we don't
* expect that most semihosting guest programs will make very
* heavy use of opening and closing fds.
*/
static int alloc_guestfd(void)
{
guint i;
if (!guestfd_array) {
/* New entries zero-initialized, i.e. type GuestFDUnused */
guestfd_array = g_array_new(FALSE, TRUE, sizeof(GuestFD));
}
/* SYS_OPEN should return nonzero handle on success. Start guestfd from 1 */
for (i = 1; i < guestfd_array->len; i++) {
GuestFD *gf = &g_array_index(guestfd_array, GuestFD, i);
if (gf->type == GuestFDUnused) {
return i;
}
}
/* All elements already in use: expand the array */
g_array_set_size(guestfd_array, i + 1);
return i;
}
/*
* Look up the guestfd in the data structure; return NULL
* for out of bounds, but don't check whether the slot is unused.
* This is used internally by the other guestfd functions.
*/
static GuestFD *do_get_guestfd(int guestfd)
{
if (!guestfd_array) {
return NULL;
}
if (guestfd <= 0 || guestfd >= guestfd_array->len) {
return NULL;
}
return &g_array_index(guestfd_array, GuestFD, guestfd);
}
/*
* Associate the specified guest fd (which must have been
* allocated via alloc_fd() and not previously used) with
* the specified host/gdb fd.
*/
static void associate_guestfd(int guestfd, int hostfd)
{
GuestFD *gf = do_get_guestfd(guestfd);
assert(gf);
gf->type = use_gdb_syscalls() ? GuestFDGDB : GuestFDHost;
gf->hostfd = hostfd;
}
/*
* Deallocate the specified guest file descriptor. This doesn't
* close the host fd, it merely undoes the work of alloc_fd().
*/
static void dealloc_guestfd(int guestfd)
{
GuestFD *gf = do_get_guestfd(guestfd);
assert(gf);
gf->type = GuestFDUnused;
}
/*
* Given a guest file descriptor, get the associated struct.
* If the fd is not valid, return NULL. This is the function
* used by the various semihosting calls to validate a handle
* from the guest.
* Note: calling alloc_guestfd() or dealloc_guestfd() will
* invalidate any GuestFD* obtained by calling this function.
*/
static GuestFD *get_guestfd(int guestfd)
{
GuestFD *gf = do_get_guestfd(guestfd);
if (!gf || gf->type == GuestFDUnused) {
return NULL;
}
return gf;
}
/*
* The semihosting API has no concept of its errno being thread-safe,
* as the API design predates SMP CPUs and was intended as a simple
* real-hardware set of debug functionality. For QEMU, we make the
* errno be per-thread in linux-user mode; in softmmu it is a simple
* global, and we assume that the guest takes care of avoiding any races.
*/
#ifndef CONFIG_USER_ONLY
static target_ulong syscall_err;
#include "exec/softmmu-semi.h"
#endif
static inline uint32_t set_swi_errno(CPUState *cs, uint32_t code)
{
if (code == (uint32_t)-1) {
#ifdef CONFIG_USER_ONLY
TaskState *ts = cs->opaque;
ts->swi_errno = errno;
#else
syscall_err = errno;
#endif
}
return code;
}
static inline uint32_t get_swi_errno(CPUState *cs)
{
#ifdef CONFIG_USER_ONLY
TaskState *ts = cs->opaque;
return ts->swi_errno;
#else
return syscall_err;
#endif
}
static target_ulong common_semi_syscall_len;
static void common_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
{
target_ulong reg0 = common_semi_arg(cs, 0);
if (ret == (target_ulong)-1) {
errno = err;
set_swi_errno(cs, -1);
reg0 = ret;
} else {
/* Fixup syscalls that use nonstardard return conventions. */
switch (reg0) {
case TARGET_SYS_WRITE:
case TARGET_SYS_READ:
reg0 = common_semi_syscall_len - ret;
break;
case TARGET_SYS_SEEK:
reg0 = 0;
break;
default:
reg0 = ret;
break;
}
}
common_semi_set_ret(cs, reg0);
}
static target_ulong common_semi_flen_buf(CPUState *cs)
{
target_ulong sp;
#ifdef TARGET_ARM
/* Return an address in target memory of 64 bytes where the remote
* gdb should write its stat struct. (The format of this structure
* is defined by GDB's remote protocol and is not target-specific.)
* We put this on the guest's stack just below SP.
*/
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
if (is_a64(env)) {
sp = env->xregs[31];
} else {
sp = env->regs[13];
}
#endif
#ifdef TARGET_RISCV
RISCVCPU *cpu = RISCV_CPU(cs);
CPURISCVState *env = &cpu->env;
sp = env->gpr[xSP];
#endif
return sp - 64;
}
static void
common_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err)
{
/* The size is always stored in big-endian order, extract
the value. We assume the size always fit in 32 bits. */
uint32_t size;
cpu_memory_rw_debug(cs, common_semi_flen_buf(cs) + 32,
(uint8_t *)&size, 4, 0);
size = be32_to_cpu(size);
common_semi_set_ret(cs, size);
errno = err;
set_swi_errno(cs, -1);
}
static int common_semi_open_guestfd;
static void
common_semi_open_cb(CPUState *cs, target_ulong ret, target_ulong err)
{
if (ret == (target_ulong)-1) {
errno = err;
set_swi_errno(cs, -1);
dealloc_guestfd(common_semi_open_guestfd);
} else {
associate_guestfd(common_semi_open_guestfd, ret);
ret = common_semi_open_guestfd;
}
common_semi_set_ret(cs, ret);
}
static target_ulong
common_semi_gdb_syscall(CPUState *cs, gdb_syscall_complete_cb cb,
const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
gdb_do_syscallv(cb, fmt, va);
va_end(va);
/*
* FIXME: in softmmu mode, the gdbstub will schedule our callback
* to occur, but will not actually call it to complete the syscall
* until after this function has returned and we are back in the
* CPU main loop. Therefore callers to this function must not
* do anything with its return value, because it is not necessarily
* the result of the syscall, but could just be the old value of X0.
* The only thing safe to do with this is that the callers of
* do_common_semihosting() will write it straight back into X0.
* (In linux-user mode, the callback will have happened before
* gdb_do_syscallv() returns.)
*
* We should tidy this up so neither this function nor
* do_common_semihosting() return a value, so the mistake of
* doing something with the return value is not possible to make.
*/
return common_semi_arg(cs, 0);
}
/*
* Types for functions implementing various semihosting calls
* for specific types of guest file descriptor. These must all
* do the work and return the required return value for the guest,
* setting the guest errno if appropriate.
*/
typedef uint32_t sys_closefn(CPUState *cs, GuestFD *gf);
typedef uint32_t sys_writefn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len);
typedef uint32_t sys_readfn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len);
typedef uint32_t sys_isattyfn(CPUState *cs, GuestFD *gf);
typedef uint32_t sys_seekfn(CPUState *cs, GuestFD *gf,
target_ulong offset);
typedef uint32_t sys_flenfn(CPUState *cs, GuestFD *gf);
static uint32_t host_closefn(CPUState *cs, GuestFD *gf)
{
/*
* Only close the underlying host fd if it's one we opened on behalf
* of the guest in SYS_OPEN.
*/
if (gf->hostfd == STDIN_FILENO ||
gf->hostfd == STDOUT_FILENO ||
gf->hostfd == STDERR_FILENO) {
return 0;
}
return set_swi_errno(cs, close(gf->hostfd));
}
static uint32_t host_writefn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
CPUArchState *env = cs->env_ptr;
uint32_t ret;
char *s = lock_user(VERIFY_READ, buf, len, 1);
(void) env; /* Used in arm softmmu lock_user implicitly */
if (!s) {
/* Return bytes not written on error */
return len;
}
ret = set_swi_errno(cs, write(gf->hostfd, s, len));
unlock_user(s, buf, 0);
if (ret == (uint32_t)-1) {
ret = 0;
}
/* Return bytes not written */
return len - ret;
}
static uint32_t host_readfn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
CPUArchState *env = cs->env_ptr;
uint32_t ret;
char *s = lock_user(VERIFY_WRITE, buf, len, 0);
(void) env; /* Used in arm softmmu lock_user implicitly */
if (!s) {
/* return bytes not read */
return len;
}
do {
ret = set_swi_errno(cs, read(gf->hostfd, s, len));
} while (ret == -1 && errno == EINTR);
unlock_user(s, buf, len);
if (ret == (uint32_t)-1) {
ret = 0;
}
/* Return bytes not read */
return len - ret;
}
static uint32_t host_isattyfn(CPUState *cs, GuestFD *gf)
{
return isatty(gf->hostfd);
}
static uint32_t host_seekfn(CPUState *cs, GuestFD *gf, target_ulong offset)
{
uint32_t ret = set_swi_errno(cs, lseek(gf->hostfd, offset, SEEK_SET));
if (ret == (uint32_t)-1) {
return -1;
}
return 0;
}
static uint32_t host_flenfn(CPUState *cs, GuestFD *gf)
{
struct stat buf;
uint32_t ret = set_swi_errno(cs, fstat(gf->hostfd, &buf));
if (ret == (uint32_t)-1) {
return -1;
}
return buf.st_size;
}
static uint32_t gdb_closefn(CPUState *cs, GuestFD *gf)
{
return common_semi_gdb_syscall(cs, common_semi_cb, "close,%x", gf->hostfd);
}
static uint32_t gdb_writefn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
common_semi_syscall_len = len;
return common_semi_gdb_syscall(cs, common_semi_cb, "write,%x,%x,%x",
gf->hostfd, buf, len);
}
static uint32_t gdb_readfn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
common_semi_syscall_len = len;
return common_semi_gdb_syscall(cs, common_semi_cb, "read,%x,%x,%x",
gf->hostfd, buf, len);
}
static uint32_t gdb_isattyfn(CPUState *cs, GuestFD *gf)
{
return common_semi_gdb_syscall(cs, common_semi_cb, "isatty,%x", gf->hostfd);
}
static uint32_t gdb_seekfn(CPUState *cs, GuestFD *gf, target_ulong offset)
{
return common_semi_gdb_syscall(cs, common_semi_cb, "lseek,%x,%x,0",
gf->hostfd, offset);
}
static uint32_t gdb_flenfn(CPUState *cs, GuestFD *gf)
{
return common_semi_gdb_syscall(cs, common_semi_flen_cb, "fstat,%x,%x",
gf->hostfd, common_semi_flen_buf(cs));
}
#define SHFB_MAGIC_0 0x53
#define SHFB_MAGIC_1 0x48
#define SHFB_MAGIC_2 0x46
#define SHFB_MAGIC_3 0x42
/* Feature bits reportable in feature byte 0 */
#define SH_EXT_EXIT_EXTENDED (1 << 0)
#define SH_EXT_STDOUT_STDERR (1 << 1)
static const uint8_t featurefile_data[] = {
SHFB_MAGIC_0,
SHFB_MAGIC_1,
SHFB_MAGIC_2,
SHFB_MAGIC_3,
SH_EXT_EXIT_EXTENDED | SH_EXT_STDOUT_STDERR, /* Feature byte 0 */
};
static void init_featurefile_guestfd(int guestfd)
{
GuestFD *gf = do_get_guestfd(guestfd);
assert(gf);
gf->type = GuestFDFeatureFile;
gf->featurefile_offset = 0;
}
static uint32_t featurefile_closefn(CPUState *cs, GuestFD *gf)
{
/* Nothing to do */
return 0;
}
static uint32_t featurefile_writefn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
/* This fd can never be open for writing */
errno = EBADF;
return set_swi_errno(cs, -1);
}
static uint32_t featurefile_readfn(CPUState *cs, GuestFD *gf,
target_ulong buf, uint32_t len)
{
CPUArchState *env = cs->env_ptr;
uint32_t i;
char *s;
(void) env; /* Used in arm softmmu lock_user implicitly */
s = lock_user(VERIFY_WRITE, buf, len, 0);
if (!s) {
return len;
}
for (i = 0; i < len; i++) {
if (gf->featurefile_offset >= sizeof(featurefile_data)) {
break;
}
s[i] = featurefile_data[gf->featurefile_offset];
gf->featurefile_offset++;
}
unlock_user(s, buf, len);
/* Return number of bytes not read */
return len - i;
}
static uint32_t featurefile_isattyfn(CPUState *cs, GuestFD *gf)
{
return 0;
}
static uint32_t featurefile_seekfn(CPUState *cs, GuestFD *gf,
target_ulong offset)
{
gf->featurefile_offset = offset;
return 0;
}
static uint32_t featurefile_flenfn(CPUState *cs, GuestFD *gf)
{
return sizeof(featurefile_data);
}
typedef struct GuestFDFunctions {
sys_closefn *closefn;
sys_writefn *writefn;
sys_readfn *readfn;
sys_isattyfn *isattyfn;
sys_seekfn *seekfn;
sys_flenfn *flenfn;
} GuestFDFunctions;
static const GuestFDFunctions guestfd_fns[] = {
[GuestFDHost] = {
.closefn = host_closefn,
.writefn = host_writefn,
.readfn = host_readfn,
.isattyfn = host_isattyfn,
.seekfn = host_seekfn,
.flenfn = host_flenfn,
},
[GuestFDGDB] = {
.closefn = gdb_closefn,
.writefn = gdb_writefn,
.readfn = gdb_readfn,
.isattyfn = gdb_isattyfn,
.seekfn = gdb_seekfn,
.flenfn = gdb_flenfn,
},
[GuestFDFeatureFile] = {
.closefn = featurefile_closefn,
.writefn = featurefile_writefn,
.readfn = featurefile_readfn,
.isattyfn = featurefile_isattyfn,
.seekfn = featurefile_seekfn,
.flenfn = featurefile_flenfn,
},
};
/*
* Read the input value from the argument block; fail the semihosting
* call if the memory read fails. Eventually we could use a generic
* CPUState helper function here.
*/
static inline bool is_64bit_semihosting(CPUArchState *env)
{
#if defined(TARGET_ARM)
return is_a64(env);
#elif defined(TARGET_RISCV)
return riscv_cpu_mxl(env) != MXL_RV32;
#else
#error un-handled architecture
#endif
}
#define GET_ARG(n) do { \
if (is_64bit_semihosting(env)) { \
if (get_user_u64(arg ## n, args + (n) * 8)) { \
errno = EFAULT; \
return set_swi_errno(cs, -1); \
} \
} else { \
if (get_user_u32(arg ## n, args + (n) * 4)) { \
errno = EFAULT; \
return set_swi_errno(cs, -1); \
} \
} \
} while (0)
#define SET_ARG(n, val) \
(is_64bit_semihosting(env) ? \
put_user_u64(val, args + (n) * 8) : \
put_user_u32(val, args + (n) * 4))
/*
* Do a semihosting call.
*
* The specification always says that the "return register" either
* returns a specific value or is corrupted, so we don't need to
* report to our caller whether we are returning a value or trying to
* leave the register unchanged. We use 0xdeadbeef as the return value
* when there isn't a defined return value for the call.
*/
target_ulong do_common_semihosting(CPUState *cs)
{
CPUArchState *env = cs->env_ptr;
target_ulong args;
target_ulong arg0, arg1, arg2, arg3;
target_ulong ul_ret;
char * s;
int nr;
uint32_t ret;
uint32_t len;
GuestFD *gf;
int64_t elapsed;
(void) env; /* Used implicitly by arm lock_user macro */
nr = common_semi_arg(cs, 0) & 0xffffffffU;
args = common_semi_arg(cs, 1);
switch (nr) {
case TARGET_SYS_OPEN:
{
int guestfd;
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
s = lock_user_string(arg0);
if (!s) {
errno = EFAULT;
return set_swi_errno(cs, -1);
}
if (arg1 >= 12) {
unlock_user(s, arg0, 0);
errno = EINVAL;
return set_swi_errno(cs, -1);
}
guestfd = alloc_guestfd();
if (guestfd < 0) {
unlock_user(s, arg0, 0);
errno = EMFILE;
return set_swi_errno(cs, -1);
}
if (strcmp(s, ":tt") == 0) {
int result_fileno;
/*
* We implement SH_EXT_STDOUT_STDERR, so:
* open for read == stdin
* open for write == stdout
* open for append == stderr
*/
if (arg1 < 4) {
result_fileno = STDIN_FILENO;
} else if (arg1 < 8) {
result_fileno = STDOUT_FILENO;
} else {
result_fileno = STDERR_FILENO;
}
associate_guestfd(guestfd, result_fileno);
unlock_user(s, arg0, 0);
return guestfd;
}
if (strcmp(s, ":semihosting-features") == 0) {
unlock_user(s, arg0, 0);
/* We must fail opens for modes other than 0 ('r') or 1 ('rb') */
if (arg1 != 0 && arg1 != 1) {
dealloc_guestfd(guestfd);
errno = EACCES;
return set_swi_errno(cs, -1);
}
init_featurefile_guestfd(guestfd);
return guestfd;
}
if (use_gdb_syscalls()) {
common_semi_open_guestfd = guestfd;
ret = common_semi_gdb_syscall(cs, common_semi_open_cb,
"open,%s,%x,1a4", arg0, (int)arg2 + 1,
gdb_open_modeflags[arg1]);
} else {
ret = set_swi_errno(cs, open(s, open_modeflags[arg1], 0644));
if (ret == (uint32_t)-1) {
dealloc_guestfd(guestfd);
} else {
associate_guestfd(guestfd, ret);
ret = guestfd;
}
}
unlock_user(s, arg0, 0);
return ret;
}
case TARGET_SYS_CLOSE:
GET_ARG(0);
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
ret = guestfd_fns[gf->type].closefn(cs, gf);
dealloc_guestfd(arg0);
return ret;
case TARGET_SYS_WRITEC:
qemu_semihosting_console_outc(cs->env_ptr, args);
return 0xdeadbeef;
case TARGET_SYS_WRITE0:
return qemu_semihosting_console_outs(cs->env_ptr, args);
case TARGET_SYS_WRITE:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
len = arg2;
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
return guestfd_fns[gf->type].writefn(cs, gf, arg1, len);
case TARGET_SYS_READ:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
len = arg2;
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
return guestfd_fns[gf->type].readfn(cs, gf, arg1, len);
case TARGET_SYS_READC:
return qemu_semihosting_console_inc(cs->env_ptr);
case TARGET_SYS_ISERROR:
GET_ARG(0);
return (target_long) arg0 < 0 ? 1 : 0;
case TARGET_SYS_ISTTY:
GET_ARG(0);
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
return guestfd_fns[gf->type].isattyfn(cs, gf);
case TARGET_SYS_SEEK:
GET_ARG(0);
GET_ARG(1);
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
return guestfd_fns[gf->type].seekfn(cs, gf, arg1);
case TARGET_SYS_FLEN:
GET_ARG(0);
gf = get_guestfd(arg0);
if (!gf) {
errno = EBADF;
return set_swi_errno(cs, -1);
}
return guestfd_fns[gf->type].flenfn(cs, gf);
case TARGET_SYS_TMPNAM:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
if (asprintf(&s, "/tmp/qemu-%x%02x", getpid(),
(int) (arg1 & 0xff)) < 0) {
return -1;
}
ul_ret = (target_ulong) -1;
/* Make sure there's enough space in the buffer */
if (strlen(s) < arg2) {
char *output = lock_user(VERIFY_WRITE, arg0, arg2, 0);
strcpy(output, s);
unlock_user(output, arg0, arg2);
ul_ret = 0;
}
free(s);
return ul_ret;
case TARGET_SYS_REMOVE:
GET_ARG(0);
GET_ARG(1);
if (use_gdb_syscalls()) {
ret = common_semi_gdb_syscall(cs, common_semi_cb, "unlink,%s",
arg0, (int)arg1 + 1);
} else {
s = lock_user_string(arg0);
if (!s) {
errno = EFAULT;
return set_swi_errno(cs, -1);
}
ret = set_swi_errno(cs, remove(s));
unlock_user(s, arg0, 0);
}
return ret;
case TARGET_SYS_RENAME:
GET_ARG(0);
GET_ARG(1);
GET_ARG(2);
GET_ARG(3);
if (use_gdb_syscalls()) {
return common_semi_gdb_syscall(cs, common_semi_cb, "rename,%s,%s",
arg0, (int)arg1 + 1, arg2,
(int)arg3 + 1);
} else {
char *s2;
s = lock_user_string(arg0);
s2 = lock_user_string(arg2);
if (!s || !s2) {
errno = EFAULT;
ret = set_swi_errno(cs, -1);
} else {
ret = set_swi_errno(cs, rename(s, s2));
}
if (s2)
unlock_user(s2, arg2, 0);
if (s)
unlock_user(s, arg0, 0);
return ret;
}
case TARGET_SYS_CLOCK:
return clock() / (CLOCKS_PER_SEC / 100);
case TARGET_SYS_TIME:
return set_swi_errno(cs, time(NULL));
case TARGET_SYS_SYSTEM:
GET_ARG(0);
GET_ARG(1);
if (use_gdb_syscalls()) {
return common_semi_gdb_syscall(cs, common_semi_cb, "system,%s",
arg0, (int)arg1 + 1);
} else {
s = lock_user_string(arg0);
if (!s) {
errno = EFAULT;
return set_swi_errno(cs, -1);
}
ret = set_swi_errno(cs, system(s));
unlock_user(s, arg0, 0);
return ret;
}
case TARGET_SYS_ERRNO:
return get_swi_errno(cs);
case TARGET_SYS_GET_CMDLINE:
{
/* Build a command-line from the original argv.
*
* The inputs are:
* * arg0, pointer to a buffer of at least the size
* specified in arg1.
* * arg1, size of the buffer pointed to by arg0 in
* bytes.
*
* The outputs are:
* * arg0, pointer to null-terminated string of the
* command line.
* * arg1, length of the string pointed to by arg0.
*/
char *output_buffer;
size_t input_size;
size_t output_size;
int status = 0;
#if !defined(CONFIG_USER_ONLY)
const char *cmdline;
#else
TaskState *ts = cs->opaque;
#endif
GET_ARG(0);
GET_ARG(1);
input_size = arg1;
/* Compute the size of the output string. */
#if !defined(CONFIG_USER_ONLY)
cmdline = semihosting_get_cmdline();
if (cmdline == NULL) {
cmdline = ""; /* Default to an empty line. */
}
output_size = strlen(cmdline) + 1; /* Count terminating 0. */
#else
unsigned int i;
output_size = ts->info->env_strings - ts->info->arg_strings;
if (!output_size) {
/*
* We special-case the "empty command line" case (argc==0).
* Just provide the terminating 0.
*/
output_size = 1;
}
#endif
if (output_size > input_size) {
/* Not enough space to store command-line arguments. */
errno = E2BIG;
return set_swi_errno(cs, -1);
}
/* Adjust the command-line length. */
if (SET_ARG(1, output_size - 1)) {
/* Couldn't write back to argument block */
errno = EFAULT;
return set_swi_errno(cs, -1);
}
/* Lock the buffer on the ARM side. */
output_buffer = lock_user(VERIFY_WRITE, arg0, output_size, 0);
if (!output_buffer) {
errno = EFAULT;
return set_swi_errno(cs, -1);
}
/* Copy the command-line arguments. */
#if !defined(CONFIG_USER_ONLY)
pstrcpy(output_buffer, output_size, cmdline);
#else
if (output_size == 1) {
/* Empty command-line. */
output_buffer[0] = '\0';
goto out;
}
if (copy_from_user(output_buffer, ts->info->arg_strings,
output_size)) {
errno = EFAULT;
status = set_swi_errno(cs, -1);
goto out;
}
/* Separate arguments by white spaces. */
for (i = 0; i < output_size - 1; i++) {
if (output_buffer[i] == 0) {
output_buffer[i] = ' ';
}
}
out:
#endif
/* Unlock the buffer on the ARM side. */
unlock_user(output_buffer, arg0, output_size);
return status;
}
case TARGET_SYS_HEAPINFO:
{
target_ulong retvals[4];
int i;
#ifdef CONFIG_USER_ONLY
TaskState *ts = cs->opaque;
target_ulong limit;
#else
LayoutInfo info = common_semi_find_bases(cs);
#endif
GET_ARG(0);
#ifdef CONFIG_USER_ONLY
/*
* Some C libraries assume the heap immediately follows .bss, so
* allocate it using sbrk.
*/
if (!ts->heap_limit) {
abi_ulong ret;
ts->heap_base = do_brk(0);
limit = ts->heap_base + COMMON_SEMI_HEAP_SIZE;
/* Try a big heap, and reduce the size if that fails. */
for (;;) {
ret = do_brk(limit);
if (ret >= limit) {
break;
}
limit = (ts->heap_base >> 1) + (limit >> 1);
}
ts->heap_limit = limit;
}
retvals[0] = ts->heap_base;
retvals[1] = ts->heap_limit;
retvals[2] = ts->stack_base;
retvals[3] = 0; /* Stack limit. */
#else
retvals[0] = info.heapbase; /* Heap Base */
retvals[1] = info.heaplimit; /* Heap Limit */
retvals[2] = info.heaplimit; /* Stack base */
retvals[3] = info.heapbase; /* Stack limit. */
#endif
for (i = 0; i < ARRAY_SIZE(retvals); i++) {
bool fail;
if (is_64bit_semihosting(env)) {
fail = put_user_u64(retvals[i], arg0 + i * 8);
} else {
fail = put_user_u32(retvals[i], arg0 + i * 4);
}
if (fail) {
/* Couldn't write back to argument block */
errno = EFAULT;
return set_swi_errno(cs, -1);
}
}
return 0;
}
case TARGET_SYS_EXIT:
case TARGET_SYS_EXIT_EXTENDED:
if (common_semi_sys_exit_extended(cs, nr)) {
/*
* The A64 version of SYS_EXIT takes a parameter block,
* so the application-exit type can return a subcode which
* is the exit status code from the application.
* SYS_EXIT_EXTENDED is an a new-in-v2.0 optional function
* which allows A32/T32 guests to also provide a status code.
*/
GET_ARG(0);
GET_ARG(1);
if (arg0 == ADP_Stopped_ApplicationExit) {
ret = arg1;
} else {
ret = 1;
}
} else {
/*
* The A32/T32 version of SYS_EXIT specifies only
* Stopped_ApplicationExit as normal exit, but does not
* allow the guest to specify the exit status code.
* Everything else is considered an error.
*/
ret = (args == ADP_Stopped_ApplicationExit) ? 0 : 1;
}
gdb_exit(ret);
exit(ret);
case TARGET_SYS_ELAPSED:
elapsed = get_clock() - clock_start;
if (sizeof(target_ulong) == 8) {
SET_ARG(0, elapsed);
} else {
SET_ARG(0, (uint32_t) elapsed);
SET_ARG(1, (uint32_t) (elapsed >> 32));
}
return 0;
case TARGET_SYS_TICKFREQ:
/* qemu always uses nsec */
return 1000000000;
case TARGET_SYS_SYNCCACHE:
/*
* Clean the D-cache and invalidate the I-cache for the specified
* virtual address range. This is a nop for us since we don't
* implement caches. This is only present on A64.
*/
#ifdef TARGET_ARM
if (is_a64(cs->env_ptr)) {
return 0;
}
#endif
#ifdef TARGET_RISCV
return 0;
#endif
/* fall through -- invalid for A32/T32 */
default:
fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);
cpu_dump_state(cs, stderr, 0);
abort();
}
}
Reference in New Issue View Git Blame Copy Permalink