From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal. Date: Fri, 20 Apr 2018 09:38:08 -0500 Message-ID: <20180420143811.9994-19-ebiederm@xmission.com> References: <87604mhrnb.fsf@xmission.com> Return-path: In-Reply-To: <87604mhrnb.fsf@xmission.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Eric W. Biederman" , Jeff Dike , Richard Weinberger , user-mode-linux-devel@lists.sourceforge.net List-Id: linux-arch.vger.kernel.org Today user mode linux only works on x86 and x86_64 and this allows simplifications of relay_signal. - x86 always set si_errno to 0 in fault handlers. - x86 does not implement si_trapno. - Only si_codes between SI_USER and SI_KERNEL have a fault address. Therefore warn if si_errno is set (it should never be). Use force_sig_info in the case where we know we have a good fault. For signals whose content it is not clear how to relay use plain force_sig and let the signal sending code come up with an appropriate generic siginfo. Cc: Jeff Dike Cc: Richard Weinberger Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: "Eric W. Biederman" --- arch/um/kernel/trap.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index d4d38520c4c6..5f0ff17cd790 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -296,9 +296,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs) { - struct faultinfo *fi; - struct siginfo clean_si; - if (!UPT_IS_USER(regs)) { if (sig == SIGBUS) printk(KERN_ERR "Bus error - the host /dev/shm or /tmp " @@ -308,29 +305,30 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs) arch_examine_signal(sig, regs); - clear_siginfo(&clean_si); - clean_si.si_signo = si->si_signo; - clean_si.si_errno = si->si_errno; - clean_si.si_code = si->si_code; + if (unlikely(si->si_errno)) { + printk(KERN_ERR "Attempted to relay signal %d (si_code = %d) with errno %d\n", + sig, si->si_code, si->si_errno); + } switch (sig) { case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGTRAP: - fi = UPT_FAULTINFO(regs); - clean_si.si_addr = (void __user *) FAULT_ADDRESS(*fi); - current->thread.arch.faultinfo = *fi; -#ifdef __ARCH_SI_TRAPNO - clean_si.si_trapno = si->si_trapno; -#endif - break; + if ((si->si_code > SI_USER) && (si->si_code < SI_KERNEL)) { + struct faultinfo *fi = UPT_FAULTINFO(regs); + current->thread.arch.faultinfo = *fi; + force_sig_fault(sig, si->si_code, + (void __user *)FAULT_ADDRESS(*fi), + current); + break; + } default: printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d)\n", sig, si->si_code); } - force_sig_info(sig, &clean_si, current); + force_sig(sig, current); } void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs) -- 2.14.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out03.mta.xmission.com ([166.70.13.233]:46782 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755162AbeDTOqB (ORCPT ); Fri, 20 Apr 2018 10:46:01 -0400 From: "Eric W. Biederman" Date: Fri, 20 Apr 2018 09:38:08 -0500 Message-ID: <20180420143811.9994-19-ebiederm@xmission.com> In-Reply-To: <87604mhrnb.fsf@xmission.com> References: <87604mhrnb.fsf@xmission.com> Subject: [REVIEW][PATCH 19/22] signal/um: Use force_sig_fault in relay_signal. Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "Eric W. Biederman" , Jeff Dike , Richard Weinberger , user-mode-linux-devel@lists.sourceforge.net Message-ID: <20180420143808.tw8rsjVXe1FxaNN243nI52ICs6Njykp4yz0sitd3g4Y@z> Today user mode linux only works on x86 and x86_64 and this allows simplifications of relay_signal. - x86 always set si_errno to 0 in fault handlers. - x86 does not implement si_trapno. - Only si_codes between SI_USER and SI_KERNEL have a fault address. Therefore warn if si_errno is set (it should never be). Use force_sig_info in the case where we know we have a good fault. For signals whose content it is not clear how to relay use plain force_sig and let the signal sending code come up with an appropriate generic siginfo. Cc: Jeff Dike Cc: Richard Weinberger Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: "Eric W. Biederman" --- arch/um/kernel/trap.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index d4d38520c4c6..5f0ff17cd790 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -296,9 +296,6 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs) { - struct faultinfo *fi; - struct siginfo clean_si; - if (!UPT_IS_USER(regs)) { if (sig == SIGBUS) printk(KERN_ERR "Bus error - the host /dev/shm or /tmp " @@ -308,29 +305,30 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs) arch_examine_signal(sig, regs); - clear_siginfo(&clean_si); - clean_si.si_signo = si->si_signo; - clean_si.si_errno = si->si_errno; - clean_si.si_code = si->si_code; + if (unlikely(si->si_errno)) { + printk(KERN_ERR "Attempted to relay signal %d (si_code = %d) with errno %d\n", + sig, si->si_code, si->si_errno); + } switch (sig) { case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGTRAP: - fi = UPT_FAULTINFO(regs); - clean_si.si_addr = (void __user *) FAULT_ADDRESS(*fi); - current->thread.arch.faultinfo = *fi; -#ifdef __ARCH_SI_TRAPNO - clean_si.si_trapno = si->si_trapno; -#endif - break; + if ((si->si_code > SI_USER) && (si->si_code < SI_KERNEL)) { + struct faultinfo *fi = UPT_FAULTINFO(regs); + current->thread.arch.faultinfo = *fi; + force_sig_fault(sig, si->si_code, + (void __user *)FAULT_ADDRESS(*fi), + current); + break; + } default: printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d)\n", sig, si->si_code); } - force_sig_info(sig, &clean_si, current); + force_sig(sig, current); } void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs) -- 2.14.1