From 09f679b62dffd437446307884597273618004b2c Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 12 Feb 2021 10:48:49 -0800 Subject: [PATCH] linux-user: Fix types in uaccess.c MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For copy_*_user, only 0 and -TARGET_EFAULT are returned; no need to involve abi_long. Use size_t for lengths. Use bool for the lock_user copy argument. Use ssize_t for target_strlen, because we can't overflow the host memory space. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-id: 20210212184902.1251044-19-richard.henderson@linaro.org [PMM: moved fix for ifdef error to previous commit] Signed-off-by: Peter Maydell --- linux-user/qemu.h | 12 +++++------- linux-user/uaccess.c | 45 +++++++++++++++++++++++---------------------- 2 files changed, 28 insertions(+), 29 deletions(-) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 971af97a2f..d25a5dafc0 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -7,8 +7,6 @@ #include "exec/cpu_ldst.h" #undef DEBUG_REMAP -#ifdef DEBUG_REMAP -#endif /* DEBUG_REMAP */ #include "exec/user/abitypes.h" @@ -629,8 +627,8 @@ static inline bool access_ok(CPUState *cpu, int type, * buffers between the target and host. These internally perform * locking/unlocking of the memory. */ -abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len); -abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len); +int copy_from_user(void *hptr, abi_ulong gaddr, size_t len); +int copy_to_user(abi_ulong gaddr, void *hptr, size_t len); /* Functions for accessing guest memory. The tget and tput functions read/write single values, byteswapping as necessary. The lock_user function @@ -640,13 +638,13 @@ abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len); /* Lock an area of guest memory into the host. If copy is true then the host area will have the same contents as the guest. */ -void *lock_user(int type, abi_ulong guest_addr, long len, int copy); +void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy); /* Unlock an area of guest memory. The first LEN bytes must be flushed back to guest memory. host_ptr = NULL is explicitly allowed and does nothing. */ #ifndef DEBUG_REMAP -static inline void unlock_user(void *host_ptr, abi_ulong guest_addr, long len) +static inline void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len) { } #else void unlock_user(void *host_ptr, abi_ulong guest_addr, long len); @@ -654,7 +652,7 @@ void unlock_user(void *host_ptr, abi_ulong guest_addr, long len); /* Return the length of a string in target memory or -TARGET_EFAULT if access error. */ -abi_long target_strlen(abi_ulong gaddr); +ssize_t target_strlen(abi_ulong gaddr); /* Like lock_user but for null terminated strings. */ void *lock_user_string(abi_ulong guest_addr); diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c index bba012ed15..76af6a92b1 100644 --- a/linux-user/uaccess.c +++ b/linux-user/uaccess.c @@ -4,7 +4,7 @@ #include "qemu.h" -void *lock_user(int type, abi_ulong guest_addr, long len, int copy) +void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy) { if (!access_ok_untagged(type, guest_addr, len)) { return NULL; @@ -26,7 +26,7 @@ void *lock_user(int type, abi_ulong guest_addr, long len, int copy) } #ifdef DEBUG_REMAP -void unlock_user(void *host_ptr, abi_ulong guest_addr, long len); +void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len); { if (!host_ptr) { return; @@ -34,7 +34,7 @@ void unlock_user(void *host_ptr, abi_ulong guest_addr, long len); if (host_ptr == g2h_untagged(guest_addr)) { return; } - if (len > 0) { + if (len != 0) { memcpy(g2h_untagged(guest_addr), host_ptr, len); } g_free(host_ptr); @@ -43,53 +43,53 @@ void unlock_user(void *host_ptr, abi_ulong guest_addr, long len); void *lock_user_string(abi_ulong guest_addr) { - abi_long len = target_strlen(guest_addr); + ssize_t len = target_strlen(guest_addr); if (len < 0) { return NULL; } - return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1); + return lock_user(VERIFY_READ, guest_addr, (size_t)len + 1, 1); } /* copy_from_user() and copy_to_user() are usually used to copy data * buffers between the target and host. These internally perform * locking/unlocking of the memory. */ -abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len) +int copy_from_user(void *hptr, abi_ulong gaddr, size_t len) { - abi_long ret = 0; - void *ghptr; + int ret = 0; + void *ghptr = lock_user(VERIFY_READ, gaddr, len, 1); - if ((ghptr = lock_user(VERIFY_READ, gaddr, len, 1))) { + if (ghptr) { memcpy(hptr, ghptr, len); unlock_user(ghptr, gaddr, 0); - } else + } else { ret = -TARGET_EFAULT; - + } return ret; } - -abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len) +int copy_to_user(abi_ulong gaddr, void *hptr, size_t len) { - abi_long ret = 0; - void *ghptr; + int ret = 0; + void *ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0); - if ((ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0))) { + if (ghptr) { memcpy(ghptr, hptr, len); unlock_user(ghptr, gaddr, len); - } else + } else { ret = -TARGET_EFAULT; + } return ret; } /* Return the length of a string in target memory or -TARGET_EFAULT if access error */ -abi_long target_strlen(abi_ulong guest_addr1) +ssize_t target_strlen(abi_ulong guest_addr1) { uint8_t *ptr; abi_ulong guest_addr; - int max_len, len; + size_t max_len, len; guest_addr = guest_addr1; for(;;) { @@ -101,11 +101,12 @@ abi_long target_strlen(abi_ulong guest_addr1) unlock_user(ptr, guest_addr, 0); guest_addr += len; /* we don't allow wrapping or integer overflow */ - if (guest_addr == 0 || - (guest_addr - guest_addr1) > 0x7fffffff) + if (guest_addr == 0 || (guest_addr - guest_addr1) > 0x7fffffff) { return -TARGET_EFAULT; - if (len != max_len) + } + if (len != max_len) { break; + } } return guest_addr - guest_addr1; } -- 2.11.4.GIT