From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32.patch added to -mm tree Date: Thu, 23 Apr 2020 19:06:38 -0700 Message-ID: <20200424020638.3zgPpwDmj%akpm@linux-foundation.org> References: <20200420181310.c18b3c0aa4dc5b3e5ec1be10@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:34296 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbgDXCGk (ORCPT ); Thu, 23 Apr 2020 22:06:40 -0400 In-Reply-To: <20200420181310.c18b3c0aa4dc5b3e5ec1be10@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: arnd@arndb.de, benh@kernel.crashing.org, ebiederm@xmission.com, hch@lst.de, jk@ozlabs.org, mm-commits@vger.kernel.org, mpe@ellerman.id.au, paulus@samba.org, viro@zeniv.linux.org.uk The patch titled Subject: signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32 has been added to the -mm tree. Its filename is signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Eric W. Biederman" Subject: signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32 To remove the use of set_fs in the coredump code there needs to be a way to convert a kernel siginfo to a userspace compat siginfo. Call that function copy_siginfo_to_compat and factor it out of copy_siginfo_to_user32. The existence of x32 complicates this code. On x32 SIGCHLD uses 64bit times for utime and stime. As only SIGCHLD is affected and SIGCHLD never causes a coredump I have avoided handling that case. Link: http://lkml.kernel.org/r/20200421154204.252921-3-hch@lst.de Signed-off-by: "Eric W. Biederman" Signed-off-by: Christoph Hellwig Cc: Alexander Viro Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Jeremy Kerr Cc: Michael Ellerman Cc: Paul Mackerras Signed-off-by: Andrew Morton --- include/linux/compat.h | 2 kernel/signal.c | 109 ++++++++++++++++++++++----------------- 2 files changed, 64 insertions(+), 47 deletions(-) --- a/include/linux/compat.h~signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32 +++ a/include/linux/compat.h @@ -402,6 +402,8 @@ long compat_get_bitmap(unsigned long *ma unsigned long bitmap_size); long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask, unsigned long bitmap_size); +void copy_siginfo_to_external32(struct compat_siginfo *to, + const struct kernel_siginfo *from); int copy_siginfo_from_user32(kernel_siginfo_t *to, const struct compat_siginfo __user *from); int copy_siginfo_to_user32(struct compat_siginfo __user *to, const kernel_siginfo_t *from); int get_compat_sigevent(struct sigevent *event, --- a/kernel/signal.c~signal-factor-copy_siginfo_to_external32-from-copy_siginfo_to_user32 +++ a/kernel/signal.c @@ -3231,94 +3231,109 @@ int copy_siginfo_from_user(kernel_siginf } #ifdef CONFIG_COMPAT -int copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct kernel_siginfo *from) -#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION) -{ - return __copy_siginfo_to_user32(to, from, in_x32_syscall()); -} -int __copy_siginfo_to_user32(struct compat_siginfo __user *to, - const struct kernel_siginfo *from, bool x32_ABI) -#endif +void copy_siginfo_to_external32(struct compat_siginfo *to, + const struct kernel_siginfo *from) { - struct compat_siginfo new; - memset(&new, 0, sizeof(new)); + /* + * This function does not work properly for SIGCHLD on x32, + * but it does not need to as SIGCHLD never causes a coredump. + */ + memset(to, 0, sizeof(*to)); - new.si_signo = from->si_signo; - new.si_errno = from->si_errno; - new.si_code = from->si_code; + to->si_signo = from->si_signo; + to->si_errno = from->si_errno; + to->si_code = from->si_code; switch(siginfo_layout(from->si_signo, from->si_code)) { case SIL_KILL: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; break; case SIL_TIMER: - new.si_tid = from->si_tid; - new.si_overrun = from->si_overrun; - new.si_int = from->si_int; + to->si_tid = from->si_tid; + to->si_overrun = from->si_overrun; + to->si_int = from->si_int; break; case SIL_POLL: - new.si_band = from->si_band; - new.si_fd = from->si_fd; + to->si_band = from->si_band; + to->si_fd = from->si_fd; break; case SIL_FAULT: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif break; case SIL_FAULT_MCEERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_addr_lsb = from->si_addr_lsb; + to->si_addr_lsb = from->si_addr_lsb; break; case SIL_FAULT_BNDERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_lower = ptr_to_compat(from->si_lower); - new.si_upper = ptr_to_compat(from->si_upper); + to->si_lower = ptr_to_compat(from->si_lower); + to->si_upper = ptr_to_compat(from->si_upper); break; case SIL_FAULT_PKUERR: - new.si_addr = ptr_to_compat(from->si_addr); + to->si_addr = ptr_to_compat(from->si_addr); #ifdef __ARCH_SI_TRAPNO - new.si_trapno = from->si_trapno; + to->si_trapno = from->si_trapno; #endif - new.si_pkey = from->si_pkey; + to->si_pkey = from->si_pkey; break; case SIL_CHLD: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; - new.si_status = from->si_status; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_status = from->si_status; + to->si_utime = from->si_utime; + to->si_stime = from->si_stime; #ifdef CONFIG_X86_X32_ABI if (x32_ABI) { - new._sifields._sigchld_x32._utime = from->si_utime; - new._sifields._sigchld_x32._stime = from->si_stime; + to->_sifields._sigchld_x32._utime = from->si_utime; + to->_sifields._sigchld_x32._stime = from->si_stime; } else #endif { - new.si_utime = from->si_utime; - new.si_stime = from->si_stime; } break; case SIL_RT: - new.si_pid = from->si_pid; - new.si_uid = from->si_uid; - new.si_int = from->si_int; + to->si_pid = from->si_pid; + to->si_uid = from->si_uid; + to->si_int = from->si_int; break; case SIL_SYS: - new.si_call_addr = ptr_to_compat(from->si_call_addr); - new.si_syscall = from->si_syscall; - new.si_arch = from->si_arch; + to->si_call_addr = ptr_to_compat(from->si_call_addr); + to->si_syscall = from->si_syscall; + to->si_arch = from->si_arch; break; } +} +int copy_siginfo_to_user32(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION) +{ + return __copy_siginfo_to_user32(to, from, in_x32_syscall()); +} +int __copy_siginfo_to_user32(struct compat_siginfo __user *to, + const struct kernel_siginfo *from, bool x32_ABI) +#endif +{ + struct compat_siginfo new; + + copy_siginfo_to_external32(&new, from); +#ifdef CONFIG_X86_X32_ABI + if (x32_ABI && from->si_signo == SIGCHLD) { + new._sifields._sigchld_x32._utime = from->si_utime; + new._sifields._sigchld_x32._stime = from->si_stime; + } +#endif if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) return -EFAULT;