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envelope-from=kariem.taha2.7@gmail.com; helo=mail-wm1-x32b.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Richard Henderson wrote: > On 9/9/23 12:36, Karim Taha wrote: >> From: Stacey Son >> >> Signed-off-by: Stacey Son >> Signed-off-by: Karim Taha >> --- >> bsd-user/bsd-mem.h | 22 ++++++++++++++++++++++ >> bsd-user/freebsd/os-syscall.c | 4 ++++ >> 2 files changed, 26 insertions(+) >> >> diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h >> index 0e16051418..1dabbe36e6 100644 >> --- a/bsd-user/bsd-mem.h >> +++ b/bsd-user/bsd-mem.h >> @@ -189,4 +189,26 @@ static inline abi_long do_bsd_minherit(abi_long addr, abi_long len, >> return get_errno(minherit(g2h_untagged(addr), len, inherit)); >> } >> >> +/* mincore(2) */ >> +static inline abi_long do_bsd_mincore(abi_ulong target_addr, abi_ulong len, >> + abi_ulong target_vec) >> +{ >> + abi_long ret; >> + void *p; >> + abi_ulong vec_len = DIV_ROUND_UP(len,TARGET_PAGE_SIZE); >> + >> + if (!guest_range_valid_untagged(target_addr,len) || !page_check_range(target_addr, len, PAGE_VALID)) { >> + return -TARGET_EFAULT; >> + } >> + >> + p = lock_user(VERIFY_WRITE, target_vec, vec_len, 0); >> + if (p == NULL) { >> + return -TARGET_EFAULT; >> + } >> + ret = get_errno(mincore(g2h_untagged(target_addr), len, p)); >> + unlock_user(p, target_vec, 0); > > You don't need the lock/unlock_user at all. It is wrongly checking for WRITE. > > > r~ > AFAIU, the host is writing to the target's memory, right? So this is similar to IPC_STAT case from the shmctl(2) syscall, where host_to_target_shmid_ds, which has a `lock_user(VERIFY_WRITE,...)`, writes the struct `dsarg` set by the host syscall `shmctl` at the address `buff` in the target memory. Is it correct if the host writes to the target without locking? for example, `mincore(g2h_untagged(target_addr), len, p)` can be done without locking. The locking was suggested by you in response to the v1 implementation which used `lock_user_string`. >> + >> + return ret; >> +} >> + >> #endif /* BSD_USER_BSD_MEM_H */ >> diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c >> index f5d60cf902..8d1cf3b35c 100644 >> --- a/bsd-user/freebsd/os-syscall.c >> +++ b/bsd-user/freebsd/os-syscall.c >> @@ -527,6 +527,10 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, >> ret = do_bsd_minherit(arg1, arg2, arg3); >> break; >> >> + case TARGET_FREEBSD_NR_mincore: /* mincore(2) */ p>> + ret = do_bsd_mincore(arg1, arg2, arg3); >> + break; >> + >> #if defined(__FreeBSD_version) && __FreeBSD_version >= 1300048 >> case TARGET_FREEBSD_NR_shm_open2: /* shm_open2(2) */ >> ret = do_freebsd_shm_open2(arg1, arg2, arg3, arg4, arg5);