From: Nadav Amit <namit@vmware.com>
To: Ingo Molnar <mingo@redhat.com>
Cc: <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
Nadav Amit <nadav.amit@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>, <linux_dti@icloud.com>,
<linux-integrity@vger.kernel.org>,
<linux-security-module@vger.kernel.org>,
Nadav Amit <namit@vmware.com>, Kees Cook <keescook@chromium.org>,
Dave Hansen <dave.hansen@intel.com>
Subject: [PATCH v7 04/14] fork: provide a function for copying init_mm
Date: Tue, 4 Dec 2018 17:33:58 -0800 [thread overview]
Message-ID: <20181205013408.47725-5-namit@vmware.com> (raw)
In-Reply-To: <20181205013408.47725-1-namit@vmware.com>
Provide a function for copying init_mm. This function will be later used
for setting a temporary mm.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
---
include/linux/sched/task.h | 1 +
kernel/fork.c | 24 ++++++++++++++++++------
2 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 108ede99e533..ac0a675678f5 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -74,6 +74,7 @@ extern void exit_itimers(struct signal_struct *);
extern long _do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *, unsigned long);
extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, int __user *);
struct task_struct *fork_idle(int);
+struct mm_struct *copy_init_mm(void);
extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
extern long kernel_wait4(pid_t, int __user *, int, struct rusage *);
diff --git a/kernel/fork.c b/kernel/fork.c
index 07cddff89c7b..01d3f5b39363 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1297,13 +1297,20 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
complete_vfork_done(tsk);
}
-/*
- * Allocate a new mm structure and copy contents from the
- * mm structure of the passed in task structure.
+/**
+ * dup_mm() - duplicates an existing mm structure
+ * @tsk: the task_struct with which the new mm will be associated.
+ * @oldmm: the mm to duplicate.
+ *
+ * Allocates a new mm structure and copy contents from the provided
+ * @oldmm structure.
+ *
+ * Return: the duplicated mm or NULL on failure.
*/
-static struct mm_struct *dup_mm(struct task_struct *tsk)
+static struct mm_struct *dup_mm(struct task_struct *tsk,
+ struct mm_struct *oldmm)
{
- struct mm_struct *mm, *oldmm = current->mm;
+ struct mm_struct *mm;
int err;
mm = allocate_mm();
@@ -1370,7 +1377,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
}
retval = -ENOMEM;
- mm = dup_mm(tsk);
+ mm = dup_mm(tsk, current->mm);
if (!mm)
goto fail_nomem;
@@ -2176,6 +2183,11 @@ struct task_struct *fork_idle(int cpu)
return task;
}
+struct mm_struct *copy_init_mm(void)
+{
+ return dup_mm(NULL, &init_mm);
+}
+
/*
* Ok, this is the main fork-routine.
*
--
2.17.1
next prev parent reply other threads:[~2018-12-05 8:52 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 1:33 [PATCH v7 00/14] x86/alternative: text_poke() enhancements Nadav Amit
2018-12-05 1:33 ` [PATCH v7 01/14] Fix "x86/alternatives: Lockdep-enforce text_mutex in text_poke*()" Nadav Amit
2018-12-05 1:33 ` [PATCH v7 02/14] x86/jump_label: Use text_poke_early() during early init Nadav Amit
2018-12-05 1:33 ` [PATCH v7 03/14] x86/mm: temporary mm struct Nadav Amit
2018-12-05 1:33 ` Nadav Amit [this message]
2018-12-05 1:33 ` [PATCH v7 05/14] x86/alternative: initializing temporary mm for patching Nadav Amit
2018-12-05 1:34 ` [PATCH v7 06/14] x86/alternative: use temporary mm for text poking Nadav Amit
2018-12-05 1:34 ` [PATCH v7 07/14] x86/kgdb: avoid redundant comparison of patched code Nadav Amit
2018-12-05 1:34 ` [PATCH v7 08/14] x86/ftrace: Use text_poke_*() infrastructure Nadav Amit
2018-12-06 0:06 ` Nadav Amit
2018-12-06 16:28 ` Ingo Molnar
2018-12-05 1:34 ` [PATCH v7 09/14] x86/kprobes: Instruction pages initialization enhancements Nadav Amit
2018-12-06 13:09 ` Masami Hiramatsu
2018-12-05 1:34 ` [PATCH v7 10/14] x86: avoid W^X being broken during modules loading Nadav Amit
2018-12-05 1:34 ` [PATCH v7 11/14] x86/jump-label: remove support for custom poker Nadav Amit
2018-12-05 1:34 ` [PATCH v7 12/14] x86/alternative: Remove the return value of text_poke_*() Nadav Amit
2018-12-05 1:34 ` [PATCH v7 13/14] module: Do not set nx for module memory before freeing Nadav Amit
2018-12-06 9:57 ` Peter Zijlstra
2018-12-06 17:28 ` Nadav Amit
2018-12-06 11:13 ` Andrea Parri
2018-12-06 18:52 ` Andy Lutomirski
2018-12-06 18:56 ` Nadav Amit
2018-12-06 20:21 ` Edgecombe, Rick P
2018-12-06 20:29 ` Nadav Amit
2018-12-13 14:10 ` Jessica Yu
2018-12-13 17:25 ` Nadav Amit
2018-12-05 1:34 ` [PATCH v7 14/14] module: Prevent module removal racing with text_poke() Nadav Amit
2018-12-06 10:01 ` Peter Zijlstra
2018-12-06 10:03 ` [PATCH v7 00/14] x86/alternative: text_poke() enhancements Peter Zijlstra
2018-12-10 1:06 ` Nadav Amit
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