From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x54a.google.com ([2607:f8b0:4864:20::54a]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gF6an-0004E2-Jz for linux-um@lists.infradead.org; Wed, 24 Oct 2018 00:00:14 +0000 Received: by mail-pg1-x54a.google.com with SMTP id v10-v6so1600860pgs.15 for ; Tue, 23 Oct 2018 16:59:58 -0700 (PDT) Date: Tue, 23 Oct 2018 16:57:44 -0700 In-Reply-To: <20181023235750.103146-1-brendanhiggins@google.com> Message-Id: <20181023235750.103146-9-brendanhiggins@google.com> Mime-Version: 1.0 References: <20181023235750.103146-1-brendanhiggins@google.com> Subject: [RFC v2 08/14] arch: um: add shim to trap to allow installing a fault catcher for tests From: Brendan Higgins List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: gregkh@linuxfoundation.org, keescook@google.com, mcgrof@kernel.org, shuah@kernel.org Cc: brakmo@fb.com, robh@kernel.org, richard@nod.at, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, mpe@ellerman.id.au, Tim.Bird@sony.com, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kieran.bingham@ideasonboard.com, julia.lawall@lip6.fr, joel@jms.id.au, linux-kselftest@vger.kernel.org, khilman@baylibre.com, joe@perches.com, daniel@ffwll.ch, dan.j.williams@intel.com, jdike@addtoit.com, Brendan Higgins , kunit-dev@googlegroups.com Add context to current thread that allows a test to specify that it wants to skip the normal checks to run an installed fault catcher. Signed-off-by: Brendan Higgins --- arch/um/include/asm/processor-generic.h | 4 +++- arch/um/kernel/trap.c | 15 +++++++++++---- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h index b58b746d3f2ca..d566cd416ff02 100644 --- a/arch/um/include/asm/processor-generic.h +++ b/arch/um/include/asm/processor-generic.h @@ -27,6 +27,7 @@ struct thread_struct { struct task_struct *prev_sched; struct arch_thread arch; jmp_buf switch_buf; + bool is_running_test; struct { int op; union { @@ -51,7 +52,8 @@ struct thread_struct { .fault_addr = NULL, \ .prev_sched = NULL, \ .arch = INIT_ARCH_THREAD, \ - .request = { 0 } \ + .request = { 0 }, \ + .is_running_test = false, \ } static inline void release_thread(struct task_struct *task) diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index cced829460427..bf90e678b3d71 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -201,6 +201,12 @@ void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs); } +static void segv_run_catcher(jmp_buf *catcher, void *fault_addr) +{ + current->thread.fault_addr = fault_addr; + UML_LONGJMP(catcher, 1); +} + /* * We give a *copy* of the faultinfo in the regs to segv. * This must be done, since nesting SEGVs could overwrite @@ -219,7 +225,10 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, if (!is_user && regs) current->thread.segv_regs = container_of(regs, struct pt_regs, regs); - if (!is_user && (address >= start_vm) && (address < end_vm)) { + catcher = current->thread.fault_catcher; + if (catcher && current->thread.is_running_test) + segv_run_catcher(catcher, (void *) address); + else if (!is_user && (address >= start_vm) && (address < end_vm)) { flush_tlb_kernel_vm(); goto out; } @@ -246,12 +255,10 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, address = 0; } - catcher = current->thread.fault_catcher; if (!err) goto out; else if (catcher != NULL) { - current->thread.fault_addr = (void *) address; - UML_LONGJMP(catcher, 1); + segv_run_catcher(catcher, (void *) address); } else if (current->thread.fault_addr != NULL) panic("fault_addr set but no fault catcher"); -- 2.19.1.568.g152ad8e336-goog _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um