diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2022-04-28 01:44:28 -0700 |
---|---|---|
committer | Richard Henderson <richard.henderson@linaro.org> | 2022-06-28 04:35:39 +0530 |
commit | 5b3f39cb04fda32226e84502f858bab06d83e5c1 (patch) | |
tree | 3e5859fb0f4457ad96b21c76ff53503363fe61d1 /semihosting | |
parent | 3753b00e5747068882c7f0302dcf9b87402993ab (diff) | |
download | qemu-5b3f39cb04fda32226e84502f858bab06d83e5c1.zip qemu-5b3f39cb04fda32226e84502f858bab06d83e5c1.tar.gz qemu-5b3f39cb04fda32226e84502f858bab06d83e5c1.tar.bz2 |
semihosting: Split out semihost_sys_open
Split out the non-ARM specific portions of SYS_OPEN to a
reusable function. This handles gdb and host file i/o.
Add helpers to validate the length of the filename string.
Prepare for usage by other semihosting by allowing the
filename length parameter to be 0, and calling strlen.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'semihosting')
-rw-r--r-- | semihosting/arm-compat-semi.c | 51 | ||||
-rw-r--r-- | semihosting/guestfd.c | 5 | ||||
-rw-r--r-- | semihosting/meson.build | 1 | ||||
-rw-r--r-- | semihosting/syscalls.c | 156 |
4 files changed, 168 insertions, 45 deletions
diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c index 72a1350..0796065 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -32,12 +32,13 @@ */ #include "qemu/osdep.h" +#include "qemu/timer.h" +#include "exec/gdbstub.h" #include "semihosting/semihost.h" #include "semihosting/console.h" #include "semihosting/common-semi.h" #include "semihosting/guestfd.h" -#include "qemu/timer.h" -#include "exec/gdbstub.h" +#include "semihosting/syscalls.h" #ifdef CONFIG_USER_ONLY #include "qemu.h" @@ -98,21 +99,6 @@ static int gdb_open_modeflags[12] = { GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND, }; -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 -}; - #ifndef CONFIG_USER_ONLY /** @@ -284,20 +270,6 @@ common_semi_flen_cb(CPUState *cs, target_ulong ret, target_ulong err) common_semi_cb(cs, ret, err); } -static int common_semi_open_guestfd; - -static void -common_semi_open_cb(CPUState *cs, target_ulong ret, target_ulong err) -{ - if (err) { - dealloc_guestfd(common_semi_open_guestfd); - } else { - associate_guestfd(common_semi_open_guestfd, ret); - ret = common_semi_open_guestfd; - } - common_semi_cb(cs, ret, err); -} - /* * Types for functions implementing various semihosting calls * for specific types of guest file descriptor. These must all @@ -601,22 +573,11 @@ void do_common_semihosting(CPUState *cs) staticfile_guestfd(ret, featurefile_data, sizeof(featurefile_data)); } - } else if (use_gdb_syscalls()) { + } else { unlock_user(s, arg0, 0); - common_semi_open_guestfd = alloc_guestfd(); - gdb_do_syscall(common_semi_open_cb, - "open,%s,%x,1a4", arg0, (int)arg2 + 1, - gdb_open_modeflags[arg1]); + semihost_sys_open(cs, common_semi_cb, arg0, arg2 + 1, + gdb_open_modeflags[arg1], 0644); break; - } else { - hostfd = open(s, open_modeflags[arg1], 0644); - if (hostfd < 0) { - ret = -1; - err = errno; - } else { - ret = alloc_guestfd(); - associate_guestfd(ret, hostfd); - } } unlock_user(s, arg0, 0); common_semi_cb(cs, ret, err); diff --git a/semihosting/guestfd.c b/semihosting/guestfd.c index b6405f5..7ac2e14 100644 --- a/semihosting/guestfd.c +++ b/semihosting/guestfd.c @@ -11,6 +11,11 @@ #include "qemu/osdep.h" #include "exec/gdbstub.h" #include "semihosting/guestfd.h" +#ifdef CONFIG_USER_ONLY +#include "qemu.h" +#else +#include "semihosting/softmmu-uaccess.h" +#endif static GArray *guestfd_array; diff --git a/semihosting/meson.build b/semihosting/meson.build index d2c1c37..8057db5 100644 --- a/semihosting/meson.build +++ b/semihosting/meson.build @@ -1,5 +1,6 @@ specific_ss.add(when: 'CONFIG_SEMIHOSTING', if_true: files( 'guestfd.c', + 'syscalls.c', )) specific_ss.add(when: ['CONFIG_SEMIHOSTING', 'CONFIG_SOFTMMU'], if_true: files( diff --git a/semihosting/syscalls.c b/semihosting/syscalls.c new file mode 100644 index 0000000..9f9d19a --- /dev/null +++ b/semihosting/syscalls.c @@ -0,0 +1,156 @@ +/* + * Syscall implementations for semihosting. + * + * Copyright (c) 2022 Linaro + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "exec/gdbstub.h" +#include "semihosting/guestfd.h" +#include "semihosting/syscalls.h" +#ifdef CONFIG_USER_ONLY +#include "qemu.h" +#else +#include "semihosting/softmmu-uaccess.h" +#endif + + +/* + * Validate or compute the length of the string (including terminator). + */ +static int validate_strlen(CPUState *cs, target_ulong str, target_ulong tlen) +{ + CPUArchState *env G_GNUC_UNUSED = cs->env_ptr; + char c; + + if (tlen == 0) { + ssize_t slen = target_strlen(str); + + if (slen < 0) { + return -EFAULT; + } + if (slen >= INT32_MAX) { + return -ENAMETOOLONG; + } + return slen + 1; + } + if (tlen > INT32_MAX) { + return -ENAMETOOLONG; + } + if (get_user_u8(c, str + tlen - 1)) { + return -EFAULT; + } + if (c != 0) { + return -EINVAL; + } + return tlen; +} + +static int validate_lock_user_string(char **pstr, CPUState *cs, + target_ulong tstr, target_ulong tlen) +{ + int ret = validate_strlen(cs, tstr, tlen); + CPUArchState *env G_GNUC_UNUSED = cs->env_ptr; + char *str = NULL; + + if (ret > 0) { + str = lock_user(VERIFY_READ, tstr, ret, true); + ret = str ? 0 : -EFAULT; + } + *pstr = str; + return ret; +} + +/* + * GDB semihosting syscall implementations. + */ + +static gdb_syscall_complete_cb gdb_open_complete; + +static void gdb_open_cb(CPUState *cs, target_ulong ret, target_ulong err) +{ + if (!err) { + int guestfd = alloc_guestfd(); + associate_guestfd(guestfd, ret); + ret = guestfd; + } + gdb_open_complete(cs, ret, err); +} + +static void gdb_open(CPUState *cs, gdb_syscall_complete_cb complete, + target_ulong fname, target_ulong fname_len, + int gdb_flags, int mode) +{ + int len = validate_strlen(cs, fname, fname_len); + if (len < 0) { + complete(cs, -1, -len); + return; + } + + gdb_open_complete = complete; + gdb_do_syscall(gdb_open_cb, "open,%s,%x,%x", + fname, len, (target_ulong)gdb_flags, (target_ulong)mode); +} + +/* + * Host semihosting syscall implementations. + */ + +static void host_open(CPUState *cs, gdb_syscall_complete_cb complete, + target_ulong fname, target_ulong fname_len, + int gdb_flags, int mode) +{ + CPUArchState *env G_GNUC_UNUSED = cs->env_ptr; + char *p; + int ret, host_flags; + + ret = validate_lock_user_string(&p, cs, fname, fname_len); + if (ret < 0) { + complete(cs, -1, -ret); + return; + } + + if (gdb_flags & GDB_O_WRONLY) { + host_flags = O_WRONLY; + } else if (gdb_flags & GDB_O_RDWR) { + host_flags = O_RDWR; + } else { + host_flags = O_RDONLY; + } + if (gdb_flags & GDB_O_CREAT) { + host_flags |= O_CREAT; + } + if (gdb_flags & GDB_O_TRUNC) { + host_flags |= O_TRUNC; + } + if (gdb_flags & GDB_O_EXCL) { + host_flags |= O_EXCL; + } + + ret = open(p, host_flags, mode); + if (ret < 0) { + complete(cs, -1, errno); + } else { + int guestfd = alloc_guestfd(); + associate_guestfd(guestfd, ret); + complete(cs, guestfd, 0); + } + unlock_user(p, fname, 0); +} + +/* + * Syscall entry points. + */ + +void semihost_sys_open(CPUState *cs, gdb_syscall_complete_cb complete, + target_ulong fname, target_ulong fname_len, + int gdb_flags, int mode) +{ + if (use_gdb_syscalls()) { + gdb_open(cs, complete, fname, fname_len, gdb_flags, mode); + } else { + host_open(cs, complete, fname, fname_len, gdb_flags, mode); + } +} |