From 1ed771b21cdb86486bd8b840d1b91bb1cd9d945e Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 13:37:24 -0700 Subject: bsd-user/freebsd/os-syscall.c: lock_iovec lock_iovec will lock an I/O vec and the memory to which it refers and create a iovec in the host space that refers to it, with full error unwinding. Add helper_iovec_unlock to unlock the partially locked iovec in case there's an error. The code will be used in iovec_unlock when that is committed. Note: memory handling likely could be rewritten to use q_autofree. That will be explored in the future since what we have now works well enough. Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/freebsd/os-syscall.c | 102 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) (limited to 'bsd-user') diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index d272478..6785193 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -74,6 +74,108 @@ bool is_error(abi_long ret) } /* + * Unlocks a iovec. Unlike unlock_iovec, it assumes the tvec array itself is + * already locked from target_addr. It will be unlocked as well as all the iovec + * elements. + */ +static void helper_unlock_iovec(struct target_iovec *target_vec, + abi_ulong target_addr, struct iovec *vec, + int count, int copy) +{ + for (int i = 0; i < count; i++) { + abi_ulong base = tswapal(target_vec[i].iov_base); + + if (vec[i].iov_base) { + unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0); + } + } + unlock_user(target_vec, target_addr, 0); +} + +struct iovec *lock_iovec(int type, abi_ulong target_addr, + int count, int copy) +{ + struct target_iovec *target_vec; + struct iovec *vec; + abi_ulong total_len, max_len; + int i; + int err = 0; + + if (count == 0) { + errno = 0; + return NULL; + } + if (count < 0 || count > IOV_MAX) { + errno = EINVAL; + return NULL; + } + + vec = g_try_new0(struct iovec, count); + if (vec == NULL) { + errno = ENOMEM; + return NULL; + } + + target_vec = lock_user(VERIFY_READ, target_addr, + count * sizeof(struct target_iovec), 1); + if (target_vec == NULL) { + err = EFAULT; + goto fail2; + } + + max_len = 0x7fffffff & MIN(TARGET_PAGE_MASK, PAGE_MASK); + total_len = 0; + + for (i = 0; i < count; i++) { + abi_ulong base = tswapal(target_vec[i].iov_base); + abi_long len = tswapal(target_vec[i].iov_len); + + if (len < 0) { + err = EINVAL; + goto fail; + } else if (len == 0) { + /* Zero length pointer is ignored. */ + vec[i].iov_base = 0; + } else { + vec[i].iov_base = lock_user(type, base, len, copy); + /* + * If the first buffer pointer is bad, this is a fault. But + * subsequent bad buffers will result in a partial write; this is + * realized by filling the vector with null pointers and zero + * lengths. + */ + if (!vec[i].iov_base) { + if (i == 0) { + err = EFAULT; + goto fail; + } else { + /* + * Fail all the subsequent addresses, they are already + * zero'd. + */ + goto out; + } + } + if (len > max_len - total_len) { + len = max_len - total_len; + } + } + vec[i].iov_len = len; + total_len += len; + } +out: + unlock_user(target_vec, target_addr, 0); + return vec; + +fail: + helper_unlock_iovec(target_vec, target_addr, vec, i, copy); +fail2: + g_free(vec); + errno = err; + return NULL; +} + +/* * do_syscall() should always have a single exit point at the end so that * actions, such as logging of syscall results, can be performed. All errnos * that do_syscall() returns must be -TARGET_. -- cgit v1.1 From 883808d84895804a3a98e211001c3edf42355b66 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 13:40:36 -0700 Subject: bsd-user/freebsd/os-syscall.c: unlock_iovec Releases the references to the iovec created by lock_iovec. Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/freebsd/os-syscall.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'bsd-user') diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 6785193..52093d4 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -175,6 +175,20 @@ fail2: return NULL; } +void unlock_iovec(struct iovec *vec, abi_ulong target_addr, + int count, int copy) +{ + struct target_iovec *target_vec; + + target_vec = lock_user(VERIFY_READ, target_addr, + count * sizeof(struct target_iovec), 1); + if (target_vec) { + helper_unlock_iovec(target_vec, target_addr, vec, count, copy); + } + + g_free(vec); +} + /* * do_syscall() should always have a single exit point at the end so that * actions, such as logging of syscall results, can be performed. All errnos -- cgit v1.1 From db69788703c5fdc590c96815c0eeeebc6a32d3e7 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 13:55:12 -0700 Subject: bsd-user/freebsd/os-syscall.c: Tracing and error boilerplate Add in the tracing and this system call not implemented boilerplate. Do this by moving the guts of do_freebsd_syscall to freebsd_syscall. Put the tracing in the wrapper function. Since freebsd_syscall is a singleton static function, it will almost certainly be inlined. Fix comments that referred to do_syscall since that was renamed some tie ago. Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/freebsd/os-syscall.c | 44 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 40 insertions(+), 4 deletions(-) (limited to 'bsd-user') diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 52093d4..1c4c998 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -190,16 +190,52 @@ void unlock_iovec(struct iovec *vec, abi_ulong target_addr, } /* - * do_syscall() should always have a single exit point at the end so that - * actions, such as logging of syscall results, can be performed. All errnos - * that do_syscall() returns must be -TARGET_. + * All errnos that freebsd_syscall() returns must be -TARGET_. + */ +static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, + abi_long arg5, abi_long arg6, abi_long arg7, + abi_long arg8) +{ + abi_long ret; + + switch (num) { + default: + qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); + ret = -TARGET_ENOSYS; + break; + } + + return ret; +} + +/* + * do_freebsd_syscall() should always have a single exit point at the end so + * that actions, such as logging of syscall results, can be performed. This + * as a wrapper around freebsd_syscall() so that actually happens. Since + * that is a singleton, modern compilers will inline it anyway... */ abi_long do_freebsd_syscall(void *cpu_env, int num, abi_long arg1, abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6, abi_long arg7, abi_long arg8) { - return 0; + CPUState *cpu = env_cpu(cpu_env); + int ret; + + trace_guest_user_syscall(cpu, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); + if (do_strace) { + print_freebsd_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6); + } + + ret = freebsd_syscall(cpu_env, num, arg1, arg2, arg3, arg4, arg5, arg6, + arg7, arg8); + if (do_strace) { + print_freebsd_syscall_ret(num, ret); + } + trace_guest_user_syscall_ret(cpu, num, ret); + + return ret; } void syscall_init(void) -- cgit v1.1 From 80da1b00886782520286e26f39ce8e21c1855072 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 16:10:10 -0700 Subject: bsd-user/bsd-file.h: Add implementations for read, pread, readv and preadv Implement do_bsd_{read,pread,readv,preadv}. Connect them to the system call table. Signed-off-by: Stacey Son Signed-off-by: Kyle Evans Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/bsd-file.h | 79 +++++++++++++++++++++++++++++++++++++++++++ bsd-user/freebsd/os-syscall.c | 28 +++++++++++++++ 2 files changed, 107 insertions(+) (limited to 'bsd-user') diff --git a/bsd-user/bsd-file.h b/bsd-user/bsd-file.h index a6bff3b..839f8c5 100644 --- a/bsd-user/bsd-file.h +++ b/bsd-user/bsd-file.h @@ -27,4 +27,83 @@ extern struct iovec *lock_iovec(int type, abi_ulong target_addr, int count, extern void unlock_iovec(struct iovec *vec, abi_ulong target_addr, int count, int copy); +ssize_t safe_read(int fd, void *buf, size_t nbytes); +ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset); +ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt); +ssize_t safe_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset); + +/* read(2) */ +static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3) +{ + abi_long ret; + void *p; + + p = lock_user(VERIFY_WRITE, arg2, arg3, 0); + if (p == NULL) { + return -TARGET_EFAULT; + } + ret = get_errno(safe_read(arg1, p, arg3)); + unlock_user(p, arg2, ret); + + return ret; +} + +/* pread(2) */ +static abi_long do_bsd_pread(void *cpu_env, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6) +{ + abi_long ret; + void *p; + + p = lock_user(VERIFY_WRITE, arg2, arg3, 0); + if (p == NULL) { + return -TARGET_EFAULT; + } + if (regpairs_aligned(cpu_env) != 0) { + arg4 = arg5; + arg5 = arg6; + } + ret = get_errno(safe_pread(arg1, p, arg3, target_arg64(arg4, arg5))); + unlock_user(p, arg2, ret); + + return ret; +} + +/* readv(2) */ +static abi_long do_bsd_readv(abi_long arg1, abi_long arg2, abi_long arg3) +{ + abi_long ret; + struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0); + + if (vec != NULL) { + ret = get_errno(safe_readv(arg1, vec, arg3)); + unlock_iovec(vec, arg2, arg3, 1); + } else { + ret = -host_to_target_errno(errno); + } + + return ret; +} + +/* preadv(2) */ +static abi_long do_bsd_preadv(void *cpu_env, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6) +{ + abi_long ret; + struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 1); + + if (vec != NULL) { + if (regpairs_aligned(cpu_env) != 0) { + arg4 = arg5; + arg5 = arg6; + } + ret = get_errno(safe_preadv(arg1, vec, arg3, target_arg64(arg4, arg5))); + unlock_iovec(vec, arg2, arg3, 0); + } else { + ret = -host_to_target_errno(errno); + } + + return ret; +} + #endif /* BSD_FILE_H */ diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 1c4c998..8ca92f2 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -42,6 +42,14 @@ #include "bsd-file.h" +/* I/O */ +safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes); +safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t, + offset); +safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt); +safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt, + off_t, offset); + void target_set_brk(abi_ulong new_brk) { } @@ -200,6 +208,26 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, abi_long ret; switch (num) { + + /* + * File system calls. + */ + case TARGET_FREEBSD_NR_read: /* read(2) */ + ret = do_bsd_read(arg1, arg2, arg3); + break; + + case TARGET_FREEBSD_NR_pread: /* pread(2) */ + ret = do_bsd_pread(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + break; + + case TARGET_FREEBSD_NR_readv: /* readv(2) */ + ret = do_bsd_readv(arg1, arg2, arg3); + break; + + case TARGET_FREEBSD_NR_preadv: /* preadv(2) */ + ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + break; + default: qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num); ret = -TARGET_ENOSYS; -- cgit v1.1 From 770d8abae736535c9bff17ee82bd48aea0e5fea4 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 16:34:03 -0700 Subject: bsd-user/bsd-file.h: Meat of the write system calls Implement write, writev, pwrite and pwritev and connect them to the system call dispatch routine. Signed-off-by: Stacey Son Signed-off-by: Kyle Evans Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/bsd-file.h | 84 +++++++++++++++++++++++++++++++++++++++++++ bsd-user/freebsd/os-syscall.c | 22 ++++++++++++ 2 files changed, 106 insertions(+) (limited to 'bsd-user') diff --git a/bsd-user/bsd-file.h b/bsd-user/bsd-file.h index 839f8c5..e9e2c85 100644 --- a/bsd-user/bsd-file.h +++ b/bsd-user/bsd-file.h @@ -32,6 +32,11 @@ ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset); ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt); ssize_t safe_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset); +ssize_t safe_write(int fd, void *buf, size_t nbytes); +ssize_t safe_pwrite(int fd, void *buf, size_t nbytes, off_t offset); +ssize_t safe_writev(int fd, const struct iovec *iov, int iovcnt); +ssize_t safe_pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset); + /* read(2) */ static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3) { @@ -106,4 +111,83 @@ static abi_long do_bsd_preadv(void *cpu_env, abi_long arg1, return ret; } +/* write(2) */ +static abi_long do_bsd_write(abi_long arg1, abi_long arg2, abi_long arg3) +{ + abi_long nbytes, ret; + void *p; + + /* nbytes < 0 implies that it was larger than SIZE_MAX. */ + nbytes = arg3; + if (nbytes < 0) { + return -TARGET_EINVAL; + } + p = lock_user(VERIFY_READ, arg2, nbytes, 1); + if (p == NULL) { + return -TARGET_EFAULT; + } + ret = get_errno(safe_write(arg1, p, arg3)); + unlock_user(p, arg2, 0); + + return ret; +} + +/* pwrite(2) */ +static abi_long do_bsd_pwrite(void *cpu_env, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6) +{ + abi_long ret; + void *p; + + p = lock_user(VERIFY_READ, arg2, arg3, 1); + if (p == NULL) { + return -TARGET_EFAULT; + } + if (regpairs_aligned(cpu_env) != 0) { + arg4 = arg5; + arg5 = arg6; + } + ret = get_errno(safe_pwrite(arg1, p, arg3, target_arg64(arg4, arg5))); + unlock_user(p, arg2, 0); + + return ret; +} + +/* writev(2) */ +static abi_long do_bsd_writev(abi_long arg1, abi_long arg2, abi_long arg3) +{ + abi_long ret; + struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1); + + if (vec != NULL) { + ret = get_errno(safe_writev(arg1, vec, arg3)); + unlock_iovec(vec, arg2, arg3, 0); + } else { + ret = -host_to_target_errno(errno); + } + + return ret; +} + +/* pwritev(2) */ +static abi_long do_bsd_pwritev(void *cpu_env, abi_long arg1, + abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6) +{ + abi_long ret; + struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1); + + if (vec != NULL) { + if (regpairs_aligned(cpu_env) != 0) { + arg4 = arg5; + arg5 = arg6; + } + ret = get_errno(safe_pwritev(arg1, vec, arg3, target_arg64(arg4, arg5))); + unlock_iovec(vec, arg2, arg3, 0); + } else { + ret = -host_to_target_errno(errno); + } + + return ret; +} + #endif /* BSD_FILE_H */ diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 8ca92f2..3a33d54 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -50,6 +50,13 @@ safe_syscall3(ssize_t, readv, int, fd, const struct iovec *, iov, int, iovcnt); safe_syscall4(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt, off_t, offset); +safe_syscall3(ssize_t, write, int, fd, void *, buf, size_t, nbytes); +safe_syscall4(ssize_t, pwrite, int, fd, void *, buf, size_t, nbytes, off_t, + offset); +safe_syscall3(ssize_t, writev, int, fd, const struct iovec *, iov, int, iovcnt); +safe_syscall4(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt, + off_t, offset); + void target_set_brk(abi_ulong new_brk) { } @@ -226,6 +233,21 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, case TARGET_FREEBSD_NR_preadv: /* preadv(2) */ ret = do_bsd_preadv(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + + case TARGET_FREEBSD_NR_write: /* write(2) */ + ret = do_bsd_write(arg1, arg2, arg3); + break; + + case TARGET_FREEBSD_NR_pwrite: /* pwrite(2) */ + ret = do_bsd_pwrite(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); + break; + + case TARGET_FREEBSD_NR_writev: /* writev(2) */ + ret = do_bsd_writev(arg1, arg2, arg3); + break; + + case TARGET_FREEBSD_NR_pwritev: /* pwritev(2) */ + ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6); break; default: -- cgit v1.1 From 9554d33076771dcc284dc3fa1a87cd0e24b91d9d Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Mon, 31 Jan 2022 17:03:30 -0700 Subject: bsd-user/freebsd/os-syscall.c: Implement exit Implement the exit system call. Bring in bsd-proc.h to contain all the process system call implementation and helper routines. Signed-off-by: Stacey Son Signed-off-by: Warner Losh Reviewed-by: Richard Henderson Reviewed-by: Kyle Evans --- bsd-user/bsd-proc.h | 42 ++++++++++++++++++++++++++++++++++++++++++ bsd-user/freebsd/os-syscall.c | 7 +++++++ 2 files changed, 49 insertions(+) create mode 100644 bsd-user/bsd-proc.h (limited to 'bsd-user') diff --git a/bsd-user/bsd-proc.h b/bsd-user/bsd-proc.h new file mode 100644 index 0000000..68b66e5 --- /dev/null +++ b/bsd-user/bsd-proc.h @@ -0,0 +1,42 @@ +/* + * process related system call shims and definitions + * + * Copyright (c) 2013-2014 Stacey D. Son + * + * 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 . + */ + +#ifndef BSD_PROC_H_ +#define BSD_PROC_H_ + +#include +#include +#include +#include +#include + +/* exit(2) */ +static inline abi_long do_bsd_exit(void *cpu_env, abi_long arg1) +{ +#ifdef TARGET_GPROF + _mcleanup(); +#endif + gdb_exit(arg1); + qemu_plugin_user_exit(); + _exit(arg1); + + return 0; +} + +#endif /* !BSD_PROC_H_ */ diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index 3a33d54..71aa0d3 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -41,6 +41,7 @@ #include "user/syscall-trace.h" #include "bsd-file.h" +#include "bsd-proc.h" /* I/O */ safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes); @@ -215,6 +216,12 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, abi_long ret; switch (num) { + /* + * process system calls + */ + case TARGET_FREEBSD_NR_exit: /* exit(2) */ + ret = do_bsd_exit(cpu_env, arg1); + break; /* * File system calls. -- cgit v1.1