From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brendan Higgins Subject: [RFC v3 08/19] arch: um: add shim to trap to allow installing a fault catcher for tests Date: Wed, 28 Nov 2018 11:36:25 -0800 Message-ID: <20181128193636.254378-9-brendanhiggins@google.com> References: <20181128193636.254378-1-brendanhiggins@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181128193636.254378-1-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, keescook-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, shuah-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: brakmo-b10kYP2dOMg@public.gmane.org, jdike-OPE4K8JWMJJBDgjK7y7TUQ@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, richard-/L3Ra7n9ekc@public.gmane.org, knut.omang-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, kieran.bingham-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org, khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, Brendan Higgins , Tim.Bird-7U/KSKJipcs@public.gmane.org, linux-um-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, julia.lawall-L2FTfq7BK8M@public.gmane.org, kunit-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, daniel-/w4YWyX8dFk@public.gmane.org, mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org, joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org List-Id: linux-nvdimm@lists.01.org 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"); -- 2.20.0.rc0.387.gc7a69e6b6c-goog