From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: peterz@infradead.org, linux-kernel@vger.kernel.org,
rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com,
jbaron@akamai.com, torvalds@linux-foundation.org,
tglx@linutronix.de, mingo@kernel.org, namit@vmware.com,
hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org,
jpoimboe@redhat.com, pbonzini@redhat.com,
mathieu.desnoyers@efficios.com, linux@rasmusvillemoes.dk
Subject: [PATCH v6 08/17] static_call: Avoid kprobes on inline static_call()s
Date: Fri, 10 Jul 2020 15:38:39 +0200 [thread overview]
Message-ID: <20200710134336.619632370@infradead.org> (raw)
In-Reply-To: 20200710133831.943894387@infradead.org
Similar to how we disallow kprobes on any other dynamic text
(ftrace/jump_label) also disallow kprobes on inline static_call()s.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/kprobes/opt.c | 4 +-
include/linux/static_call.h | 11 +++++++
kernel/kprobes.c | 2 +
kernel/static_call.c | 64 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 80 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -17,6 +17,7 @@
#include <linux/ftrace.h>
#include <linux/frame.h>
#include <linux/pgtable.h>
+#include <linux/static_call.h>
#include <asm/text-patching.h>
#include <asm/cacheflush.h>
@@ -209,7 +210,8 @@ static int copy_optimized_instructions(u
/* Check whether the address range is reserved */
if (ftrace_text_reserved(src, src + len - 1) ||
alternatives_text_reserved(src, src + len - 1) ||
- jump_label_text_reserved(src, src + len - 1))
+ jump_label_text_reserved(src, src + len - 1) ||
+ static_call_text_reserved(src, src + len - 1))
return -EBUSY;
return len;
--- a/include/linux/static_call.h
+++ b/include/linux/static_call.h
@@ -110,6 +110,7 @@ struct static_call_key {
extern void __static_call_update(struct static_call_key *key, void *tramp, void *func);
extern int static_call_mod_init(struct module *mod);
+extern int static_call_text_reserved(void *start, void *end);
#define DEFINE_STATIC_CALL(name, _func) \
DECLARE_STATIC_CALL(name, _func); \
@@ -153,6 +154,11 @@ void __static_call_update(struct static_
cpus_read_unlock();
}
+static inline int static_call_text_reserved(void *start, void *end)
+{
+ return 0;
+}
+
#define EXPORT_STATIC_CALL(name) \
EXPORT_SYMBOL(STATIC_CALL_KEY(name)); \
EXPORT_SYMBOL(STATIC_CALL_TRAMP(name))
@@ -182,6 +188,11 @@ void __static_call_update(struct static_
WRITE_ONCE(key->func, func);
}
+static inline int static_call_text_reserved(void *start, void *end)
+{
+ return 0;
+}
+
#define EXPORT_STATIC_CALL(name) EXPORT_SYMBOL(STATIC_CALL_KEY(name))
#define EXPORT_STATIC_CALL_GPL(name) EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name))
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -35,6 +35,7 @@
#include <linux/ftrace.h>
#include <linux/cpu.h>
#include <linux/jump_label.h>
+#include <linux/static_call.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
@@ -1591,6 +1592,7 @@ static int check_kprobe_address_safe(str
if (!kernel_text_address((unsigned long) p->addr) ||
within_kprobe_blacklist((unsigned long) p->addr) ||
jump_label_text_reserved(p->addr, p->addr) ||
+ static_call_text_reserved(p->addr, p->addr) ||
find_bug((unsigned long)p->addr)) {
ret = -EINVAL;
goto out;
--- a/kernel/static_call.c
+++ b/kernel/static_call.c
@@ -204,8 +204,58 @@ static int __static_call_init(struct mod
return 0;
}
+static int addr_conflict(struct static_call_site *site, void *start, void *end)
+{
+ unsigned long addr = (unsigned long)static_call_addr(site);
+
+ if (addr <= (unsigned long)end &&
+ addr + CALL_INSN_SIZE > (unsigned long)start)
+ return 1;
+
+ return 0;
+}
+
+static int __static_call_text_reserved(struct static_call_site *iter_start,
+ struct static_call_site *iter_stop,
+ void *start, void *end)
+{
+ struct static_call_site *iter = iter_start;
+
+ while (iter < iter_stop) {
+ if (addr_conflict(iter, start, end))
+ return 1;
+ iter++;
+ }
+
+ return 0;
+}
+
#ifdef CONFIG_MODULES
+static int __static_call_mod_text_reserved(void *start, void *end)
+{
+ struct module *mod;
+ int ret;
+
+ preempt_disable();
+ mod = __module_text_address((unsigned long)start);
+ WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod);
+ if (!try_module_get(mod))
+ mod = NULL;
+ preempt_enable();
+
+ if (!mod)
+ return 0;
+
+ ret = __static_call_text_reserved(mod->static_call_sites,
+ mod->static_call_sites + mod->num_static_call_sites,
+ start, end);
+
+ module_put(mod);
+
+ return ret;
+}
+
static int static_call_add_module(struct module *mod)
{
return __static_call_init(mod, mod->static_call_sites,
@@ -275,6 +325,20 @@ static struct notifier_block static_call
#endif /* CONFIG_MODULES */
+int static_call_text_reserved(void *start, void *end)
+{
+ int ret = __static_call_text_reserved(__start_static_call_sites,
+ __stop_static_call_sites, start, end);
+
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_MODULES
+ ret = __static_call_mod_text_reserved(start, end);
+#endif
+ return ret;
+}
+
static void __init static_call_init(void)
{
int ret;
next prev parent reply other threads:[~2020-07-10 13:46 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 13:38 [PATCH v6 00/17] Add static_call Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 01/17] notifier: Fix broken error handling pattern Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 02/17] module: Fix up module_notifier return values Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 03/17] module: Properly propagate MODULE_STATE_COMING failure Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 04/17] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 05/17] compiler.h: Make __ADDRESSABLE() symbol truly unique Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 06/17] static_call: Add basic static call infrastructure Peter Zijlstra
2020-07-10 21:56 ` Steven Rostedt
2020-07-10 13:38 ` [PATCH v6 07/17] static_call: Add inline " Peter Zijlstra
2020-07-10 21:57 ` Steven Rostedt
2020-07-10 13:38 ` Peter Zijlstra [this message]
2020-07-10 22:00 ` [PATCH v6 08/17] static_call: Avoid kprobes on inline static_call()s Steven Rostedt
2020-07-11 10:30 ` Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 09/17] x86/static_call: Add out-of-line static call implementation Peter Zijlstra
2020-07-10 22:13 ` Steven Rostedt
2020-07-11 10:11 ` Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 10/17] x86/static_call: Add inline static call implementation for x86-64 Peter Zijlstra
2020-07-10 22:31 ` Steven Rostedt
2020-07-11 9:56 ` Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 11/17] static_call: Simple self-test Peter Zijlstra
2020-07-10 22:42 ` Steven Rostedt
2020-07-11 10:27 ` Peter Zijlstra
2020-07-13 20:26 ` Steven Rostedt
2020-07-10 13:38 ` [PATCH v6 12/17] x86/alternatives: Teach text_poke_bp() to emulate RET Peter Zijlstra
2020-07-10 22:44 ` Steven Rostedt
2020-07-10 13:38 ` [PATCH v6 13/17] static_call: Add static_call_cond() Peter Zijlstra
2020-07-10 23:08 ` Steven Rostedt
2020-07-11 5:09 ` Peter Zijlstra
2020-07-11 10:49 ` Peter Zijlstra
2020-07-13 20:32 ` Steven Rostedt
2020-07-14 9:53 ` Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 14/17] static_call: Handle tail-calls Peter Zijlstra
2020-07-11 0:23 ` Steven Rostedt
2020-07-11 5:06 ` Peter Zijlstra
2020-07-11 5:08 ` Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 15/17] static_call: Allow early init Peter Zijlstra
2020-07-11 1:14 ` Steven Rostedt
2020-07-11 5:08 ` Peter Zijlstra
2020-07-13 20:24 ` Steven Rostedt
2020-07-14 9:51 ` Peter Zijlstra
2020-07-14 14:16 ` Steven Rostedt
2020-07-14 15:54 ` Peter Zijlstra
2020-07-14 16:07 ` Steven Rostedt
2020-07-14 18:31 ` Peter Zijlstra
2020-07-14 19:38 ` Steven Rostedt
2020-07-10 13:38 ` [PATCH v6 16/17] tracepoint: Optimize using static_call() Peter Zijlstra
2020-07-10 13:38 ` [PATCH v6 17/17] x86/perf, static_call: Optimize x86_pmu methods Peter Zijlstra
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