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[219.123.138.129]) by smtp.gmail.com with ESMTPSA id e11sm2919216pfl.58.2020.10.06.02.45.14 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 06 Oct 2020 02:45:16 -0700 (PDT) Received: by earth-mac.local (Postfix, from userid 501) id EF1B620390F4AC; Tue, 6 Oct 2020 18:45:10 +0900 (JST) From: Hajime Tazaki To: linux-um@lists.infradead.org, jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com Subject: [RFC v7 07/21] um: extend arch_switch_to for alternate SUBARCH Date: Tue, 6 Oct 2020 18:44:16 +0900 Message-Id: X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201006_054519_201303_40CC3174 X-CRM114-Status: GOOD ( 14.30 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:643 listed in] [list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider [thehajime[at]gmail.com] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tavi.purdila@gmail.com, linux-kernel-library@freelists.org, linux-arch@vger.kernel.org, Hajime Tazaki , retrage01@gmail.com Sender: "linux-um" Errors-To: linux-um-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This commit introduces additional argument of previous task when context switch happens. New SUBARCH can use the new information to switch tasks in a subarch-specific manner. The patch is particularly required by nommu mode implemented as a SUBARCH of UML. Signed-off-by: Hajime Tazaki --- arch/um/kernel/process.c | 6 +++--- arch/x86/um/ptrace_32.c | 2 +- arch/x86/um/syscalls_64.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 26b5e243d3fc..87a8cfa228ca 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -80,7 +80,7 @@ static inline void set_current(struct task_struct *task) { external_pid(), task }); } -extern void arch_switch_to(struct task_struct *to); +extern void arch_switch_to(struct task_struct *from, struct task_struct *to); void *__switch_to(struct task_struct *from, struct task_struct *to) { @@ -88,7 +88,7 @@ void *__switch_to(struct task_struct *from, struct task_struct *to) set_current(to); switch_threads(&from->thread.switch_buf, &to->thread.switch_buf); - arch_switch_to(current); + arch_switch_to(from, to); return current->thread.prev_sched; } @@ -145,7 +145,7 @@ void fork_handler(void) * arch_switch_to isn't needed. We could want to apply this to * improve performance. -bb */ - arch_switch_to(current); + arch_switch_to(NULL, current); current->thread.prev_sched = NULL; diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c index 2497bac56066..0f184710d4ca 100644 --- a/arch/x86/um/ptrace_32.c +++ b/arch/x86/um/ptrace_32.c @@ -11,7 +11,7 @@ extern int arch_switch_tls(struct task_struct *to); -void arch_switch_to(struct task_struct *to) +void arch_switch_to(struct task_struct *from, struct task_struct *to) { int err = arch_switch_tls(to); if (!err) diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c index 58f51667e2e4..2ef9474d2bd2 100644 --- a/arch/x86/um/syscalls_64.c +++ b/arch/x86/um/syscalls_64.c @@ -80,7 +80,7 @@ SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2) return arch_prctl(current, option, (unsigned long __user *) arg2); } -void arch_switch_to(struct task_struct *to) +void arch_switch_to(struct task_struct *from, struct task_struct *to) { if ((to->thread.arch.fs == 0) || (to->mm == NULL)) return;