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s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=9D74vhDKZ9zweNX8bjF2N0Y9OEVlGStLvbWGF8he3rU=; b=FfPeHLuZ+9MkSPDdw4WusWN73AqUJvEvV7Awf+lk/vyJJ1ZYgo79iOfFG6H5t6cU9/ FSYvfwHSPutdZRnQNnJbrn8y5yfEzNWP3pjDDI6f34KchCSvQQDLvnAN70hX9sf+GW3D KZ12GWxGu3Kv3BE55o7JPAWOpGs3kqUmgjzFuZyOQIYNYzAc+c/fpobV3KPxE4uUL5Kc /Jn8/uFj69E6rjrBxwp+OTKldLo0gRjF/cfnFliCSwXP/UhaYWgfrT6Fh6Ie2UFkeSo8 P1hHpW2p6JAUackkaDFiESz5yclc+uEYAGiLeLWezpB1aGNR0icKV84vC+on+JefUTc8 o2ow== X-Gm-Message-State: AA+aEWamOP7jorR0QXM83QJ0Znm7kCc4lsrsyKZATVs0ZugjcBTMrw6O nUjyO5Ys2A3qd+EggZjCIU5EieW+MIK/6ZUZcI/qwQ== X-Google-Smtp-Source: AFSGD/UMhQyCRg6KQGlfagnXK2iwxLqCIGZ8HodTaJ7DpYmtIhCG98itNlSoTEwnNmng08QDMUsUiZnMCHqxdM/0JGaFXw== X-Received: by 2002:a24:74b:: with SMTP id f72-v6mr3353404itf.35.1543433883605; Wed, 28 Nov 2018 11:38:03 -0800 (PST) Date: Wed, 28 Nov 2018 11:36:25 -0800 In-Reply-To: <20181128193636.254378-1-brendanhiggins@google.com> Message-Id: <20181128193636.254378-9-brendanhiggins@google.com> Mime-Version: 1.0 References: <20181128193636.254378-1-brendanhiggins@google.com> X-Mailer: git-send-email 2.20.0.rc0.387.gc7a69e6b6c-goog Subject: [RFC v3 08/19] arch: um: add shim to trap to allow installing a fault catcher for tests From: Brendan Higgins To: gregkh@linuxfoundation.org, keescook@google.com, mcgrof@kernel.org, shuah@kernel.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181128_113815_666214_FCC83823 X-CRM114-Status: GOOD ( 10.44 ) X-Spam-Score: -7.7 (-------) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-7.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:d4a listed in] [list.dnswl.org] -7.5 USER_IN_DEF_DKIM_WL From: address is in the default DKIM white-list -0.0 SPF_PASS SPF: sender matches SPF record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_MED DKIMwl.org - Whitelisted Medium sender X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: brakmo@fb.com, jdike@addtoit.com, dri-devel@lists.freedesktop.org, linux-kselftest@vger.kernel.org, frowand.list@gmail.com, robh@kernel.org, linux-nvdimm@lists.01.org, richard@nod.at, knut.omang@oracle.com, kieran.bingham@ideasonboard.com, joel@jms.id.au, khilman@baylibre.com, Brendan Higgins , Tim.Bird@sony.com, linux-um@lists.infradead.org, rostedt@goodmis.org, julia.lawall@lip6.fr, dan.j.williams@intel.com, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, daniel@ffwll.ch, mpe@ellerman.id.au, joe@perches.com Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.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");