From: Nadav Amit <namit@vmware.com>
To: Ingo Molnar <mingo@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"H . Peter Anvin " <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
<linux-kernel@vger.kernel.org>, Nadav Amit <nadav.amit@gmail.com>,
<x86@kernel.org>, Borislav Petkov <bp@alien8.de>,
David Woodhouse <dwmw@amazon.co.uk>,
Nadav Amit <namit@vmware.com>
Subject: [RFC PATCH 3/5] x86: interface for accessing indirect branch locations
Date: Wed, 17 Oct 2018 17:54:18 -0700 [thread overview]
Message-ID: <20181018005420.82993-4-namit@vmware.com> (raw)
In-Reply-To: <20181018005420.82993-1-namit@vmware.com>
Adding a C interface to access the locations of indirect branches. To be
used for dynamic patching.
Signed-off-by: Nadav Amit <namit@vmware.com>
---
arch/x86/include/asm/nospec-branch.h | 1 -
arch/x86/include/asm/sections.h | 2 ++
include/linux/module.h | 5 +++++
kernel/module.c | 8 ++++++++
4 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index bd2d3a41e88c..a4496c141143 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -406,7 +406,6 @@ struct relpoline_entry {
u8 reg;
} __packed;
-
/* The Intel SPEC CTRL MSR base value cache */
extern u64 x86_spec_ctrl_base;
diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h
index 8ea1cfdbeabc..e8dd9c40ecd5 100644
--- a/arch/x86/include/asm/sections.h
+++ b/arch/x86/include/asm/sections.h
@@ -4,6 +4,7 @@
#include <asm-generic/sections.h>
#include <asm/extable.h>
+#include <asm/nospec-branch.h>
extern char __brk_base[], __brk_limit[];
extern struct exception_table_entry __stop___ex_table[];
@@ -11,6 +12,7 @@ extern char __end_rodata_aligned[];
#if defined(CONFIG_X86_64)
extern char __end_rodata_hpage_align[];
+extern const struct relpoline_entry __relpolines[], __relpolines_end[];
#endif
#endif /* _ASM_X86_SECTIONS_H */
diff --git a/include/linux/module.h b/include/linux/module.h
index f807f15bebbe..29ff390f8339 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -39,6 +39,7 @@ struct modversion_info {
struct module;
struct exception_table_entry;
+struct relpoline_entry;
struct module_kobject {
struct kobject kobj;
@@ -387,6 +388,10 @@ struct module {
unsigned int num_exentries;
struct exception_table_entry *extable;
+ /* Cachepolines */
+ unsigned int num_relpolines;
+ struct relpoline_entry *relpolines;
+
/* Startup function. */
int (*init)(void);
diff --git a/kernel/module.c b/kernel/module.c
index 49a405891587..e34fc28875bd 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -64,6 +64,7 @@
#include <linux/bsearch.h>
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
+#include <asm/nospec-branch.h>
#include <uapi/linux/module.h>
#include "module-internal.h"
@@ -256,6 +257,7 @@ static void mod_update_bounds(struct module *mod)
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */
+struct list_head *cachepoline_modules = &modules;
static void module_assert_mutex(void)
{
@@ -3125,6 +3127,12 @@ static int find_module_sections(struct module *mod, struct load_info *info)
mod->extable = section_objs(info, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);
+#ifdef CONFIG_X86_64
+ mod->relpolines = section_objs(info, "__relpolines",
+ sizeof(*mod->relpolines),
+ &mod->num_relpolines);
+#endif
+
if (section_addr(info, "__obsparm"))
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
--
2.17.1
next prev parent reply other threads:[~2018-10-18 0:56 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 0:54 [RFC PATCH 0/5] x86: dynamic indirect call promotion Nadav Amit
2018-10-18 0:54 ` [RFC PATCH 1/5] x86: introduce preemption disable prefix Nadav Amit
2018-10-18 1:22 ` Andy Lutomirski
2018-10-18 3:12 ` Nadav Amit
2018-10-18 3:26 ` Nadav Amit
2018-10-18 3:51 ` Andy Lutomirski
2018-10-18 16:47 ` Nadav Amit
2018-10-18 17:00 ` Andy Lutomirski
2018-10-18 17:25 ` Nadav Amit
2018-10-18 17:29 ` Andy Lutomirski
2018-10-18 17:42 ` Nadav Amit
2018-10-19 1:08 ` Nadav Amit
2018-10-19 4:29 ` Andy Lutomirski
2018-10-19 4:44 ` Nadav Amit
2018-10-20 1:22 ` Masami Hiramatsu
2018-10-19 5:00 ` Alexei Starovoitov
2018-10-19 8:22 ` Peter Zijlstra
2018-10-19 14:47 ` Alexei Starovoitov
2018-10-19 8:19 ` Peter Zijlstra
2018-10-19 10:38 ` Oleg Nesterov
2018-10-19 8:33 ` Peter Zijlstra
2018-10-19 14:29 ` Andy Lutomirski
2018-11-29 9:46 ` Peter Zijlstra
2018-10-18 7:54 ` Peter Zijlstra
2018-10-18 18:14 ` Nadav Amit
2018-10-18 0:54 ` [RFC PATCH 2/5] x86: patch indirect branch promotion Nadav Amit
2018-10-18 0:54 ` Nadav Amit [this message]
2018-10-18 0:54 ` [RFC PATCH 4/5] x86: learning and patching indirect branch targets Nadav Amit
2018-10-18 0:54 ` [RFC PATCH 5/5] x86: relpoline: disabling interface Nadav Amit
2018-10-23 18:36 ` [RFC PATCH 0/5] x86: dynamic indirect call promotion Dave Hansen
2018-10-23 20:32 ` Nadav Amit
2018-10-23 20:37 ` Dave Hansen
2018-11-28 16:08 ` Josh Poimboeuf
2018-11-28 19:34 ` Nadav Amit
2018-11-29 0:38 ` Josh Poimboeuf
2018-11-29 1:40 ` Andy Lutomirski
2018-11-29 2:06 ` Nadav Amit
2018-11-29 3:24 ` Andy Lutomirski
2018-11-29 4:36 ` Josh Poimboeuf
2018-11-29 6:06 ` Andy Lutomirski
2018-11-29 15:19 ` Josh Poimboeuf
2018-12-01 6:52 ` Nadav Amit
2018-12-01 14:25 ` Josh Poimboeuf
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