From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andi Kleen <ak@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
"H. Peter Anvin" <hpa@zytor.com>, Miroslav Benes <mbenes@suse.cz>,
"Paul E. McKenney" <paulmck@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Babu Moger <Babu.Moger@amd.com>, Nayna Jain <nayna@linux.ibm.com>,
Omar Sandoval <osandov@fb.com>, Marco Elver <elver@google.com>,
Andy Lutomirski <luto@kernel.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v4 4/7] arch/x86: Implement text_alloc() and text_free()
Date: Fri, 17 Jul 2020 06:04:18 +0300 [thread overview]
Message-ID: <20200717030422.679972-5-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20200717030422.679972-1-jarkko.sakkinen@linux.intel.com>
Implement text_alloc() and text_free() with vmalloc() and vfree(), thus
dropping the dependency to the module subsystem.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
arch/x86/Kconfig | 3 +++
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/text_alloc.c | 41 ++++++++++++++++++++++++++++++++++++
3 files changed, 45 insertions(+)
create mode 100644 arch/x86/kernel/text_alloc.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0dea7fdd7a00..a4ee5d1300f6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2035,6 +2035,9 @@ config KEXEC_FILE
config ARCH_HAS_KEXEC_PURGATORY
def_bool KEXEC_FILE
+config ARCH_HAS_TEXT_ALLOC
+ def_bool y
+
config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index e77261db2391..fa1415424ae3 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -68,6 +68,7 @@ obj-y += tsc.o tsc_msr.o io_delay.o rtc.o
obj-y += pci-iommu_table.o
obj-y += resource.o
obj-y += irqflags.o
+obj-y += text_alloc.o
obj-y += process.o
obj-y += fpu/
diff --git a/arch/x86/kernel/text_alloc.c b/arch/x86/kernel/text_alloc.c
new file mode 100644
index 000000000000..c8e5296ebceb
--- /dev/null
+++ b/arch/x86/kernel/text_alloc.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Kernel module help for x86.
+ * Copyright (C) 2001 Rusty Russell.
+ */
+
+#include <linux/kasan.h>
+#include <linux/mm.h>
+#include <linux/moduleloader.h>
+#include <linux/vmalloc.h>
+#include <asm/setup.h>
+
+void *text_alloc(unsigned long size)
+{
+ void *p;
+
+ if (PAGE_ALIGN(size) > MODULES_LEN)
+ return NULL;
+
+ p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END,
+ GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
+ __builtin_return_address(0));
+
+ if (p && (kasan_module_alloc(p, size) < 0)) {
+ vfree(p);
+ return NULL;
+ }
+
+ return p;
+}
+
+void text_free(void *region)
+{
+ /*
+ * This memory may be RO, and freeing RO memory in an interrupt is not
+ * supported by vmalloc.
+ */
+ WARN_ON(in_interrupt());
+
+ vfree(region);
+}
--
2.25.1
next prev parent reply other threads:[~2020-07-17 3:05 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 3:04 [PATCH v4 0/7] arch/x86: kprobes: Remove MODULES dependency Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 1/7] module: Add lock_modules() and unlock_modules() Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 2/7] kprobes: Use " Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 3/7] vmalloc: Add text_alloc() and text_free() Jarkko Sakkinen
2020-07-17 5:33 ` kernel test robot
2020-07-17 5:33 ` kernel test robot
2020-07-17 8:52 ` Masami Hiramatsu
2020-07-23 22:24 ` Jarkko Sakkinen
2020-07-18 16:23 ` Mike Rapoport
2020-07-20 12:01 ` Masami Hiramatsu
2020-07-23 22:28 ` Jarkko Sakkinen
2020-07-24 10:13 ` Mike Rapoport
2020-07-24 23:31 ` Jarkko Sakkinen
2020-07-24 23:40 ` Jarkko Sakkinen
2020-07-17 3:04 ` Jarkko Sakkinen [this message]
2020-07-17 3:04 ` [PATCH v4 5/7] arch/x86: kprobes: Use text_alloc() in alloc_insn_page() Jarkko Sakkinen
2020-07-23 22:16 ` Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 6/7] kprobes: Use text_alloc() and text_free() Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 7/7] kprobes: Flag out CONFIG_MODULES dependent code Jarkko Sakkinen
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