Replace instrumentation_begin() with instrumentation_begin_with_regs()
to let KMSAN handle the non-instrumented code and unpoison pt_regs
passed from the instrumented part. This is done to reduce the number of
false positive reports.
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
v2:
-- this patch was previously called "x86: kmsan: handle register
passing from uninstrumented code". Instead of adding KMSAN-specific
code to every instrumentation_begin()/instrumentation_end() section,
we changed instrumentation_begin() to
instrumentation_begin_with_regs() where applicable.
Link: https://linux-review.googlesource.com/id/I435ec076cd21752c2f877f5da81f5eced62a2ea4
---
arch/x86/entry/common.c | 3 ++-
arch/x86/include/asm/idtentry.h | 10 +++++-----
arch/x86/kernel/cpu/mce/core.c | 2 +-
arch/x86/kernel/kvm.c | 2 +-
arch/x86/kernel/nmi.c | 2 +-
arch/x86/kernel/sev.c | 4 ++--
arch/x86/kernel/traps.c | 14 +++++++-------
arch/x86/mm/fault.c | 2 +-
8 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 6c2826417b337..047d157987859 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -14,6 +14,7 @@
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
+#include <linux/kmsan.h>
#include <linux/ptrace.h>
#include <linux/export.h>
#include <linux/nospec.h>
@@ -75,7 +76,7 @@ __visible noinstr void do_syscall_64(struct pt_regs *regs, int nr)
add_random_kstack_offset();
nr = syscall_enter_from_user_mode(regs, nr);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
if (!do_syscall_x64(regs, nr) && !do_syscall_x32(regs, nr) && nr != -1) {
/* Invalid system call, but still a system call. */
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 1345088e99025..f24ff33fc3681 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -51,7 +51,7 @@ __visible noinstr void func(struct pt_regs *regs) \
{ \
irqentry_state_t state = irqentry_enter(regs); \
\
- instrumentation_begin(); \
+ instrumentation_begin_with_regs(regs); \
__##func (regs); \
instrumentation_end(); \
irqentry_exit(regs, state); \
@@ -98,7 +98,7 @@ __visible noinstr void func(struct pt_regs *regs, \
{ \
irqentry_state_t state = irqentry_enter(regs); \
\
- instrumentation_begin(); \
+ instrumentation_begin_with_regs(regs); \
__##func (regs, error_code); \
instrumentation_end(); \
irqentry_exit(regs, state); \
@@ -195,7 +195,7 @@ __visible noinstr void func(struct pt_regs *regs, \
irqentry_state_t state = irqentry_enter(regs); \
u32 vector = (u32)(u8)error_code; \
\
- instrumentation_begin(); \
+ instrumentation_begin_with_regs(regs); \
kvm_set_cpu_l1tf_flush_l1d(); \
run_irq_on_irqstack_cond(__##func, regs, vector); \
instrumentation_end(); \
@@ -235,7 +235,7 @@ __visible noinstr void func(struct pt_regs *regs) \
{ \
irqentry_state_t state = irqentry_enter(regs); \
\
- instrumentation_begin(); \
+ instrumentation_begin_with_regs(regs); \
kvm_set_cpu_l1tf_flush_l1d(); \
run_sysvec_on_irqstack_cond(__##func, regs); \
instrumentation_end(); \
@@ -262,7 +262,7 @@ __visible noinstr void func(struct pt_regs *regs) \
{ \
irqentry_state_t state = irqentry_enter(regs); \
\
- instrumentation_begin(); \
+ instrumentation_begin_with_regs(regs); \
__irq_enter_raw(); \
kvm_set_cpu_l1tf_flush_l1d(); \
__##func (regs); \
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 5818b837fd4d4..7b8c43d8727cc 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1355,7 +1355,7 @@ static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callba
/* Handle unconfigured int18 (should never happen) */
static noinstr void unexpected_machine_check(struct pt_regs *regs)
{
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
smp_processor_id());
instrumentation_end();
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index d77481ecb0d5f..eaed9b412908c 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -249,7 +249,7 @@ noinstr bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
return false;
state = irqentry_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
/*
* If the host managed to inject an async #PF into an interrupt
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 4bce802d25fb1..3f987a5dc38c7 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -329,7 +329,7 @@ static noinstr void default_do_nmi(struct pt_regs *regs)
__this_cpu_write(last_nmi_rip, regs->ip);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
handled = nmi_handle(NMI_LOCAL, regs);
__this_cpu_add(nmi_stats.normal, handled);
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index e6d316a01fdd4..9bfc29fc9c983 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1330,7 +1330,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
irq_state = irqentry_nmi_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
if (!vc_raw_handle_exception(regs, error_code)) {
/* Show some debug info */
@@ -1362,7 +1362,7 @@ DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
}
irqentry_enter_from_user_mode(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
if (!vc_raw_handle_exception(regs, error_code)) {
/*
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 8143693a7ea6e..f08741abc0e5b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -229,7 +229,7 @@ static noinstr bool handle_bug(struct pt_regs *regs)
/*
* All lies, just get the WARN/BUG out.
*/
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
/*
* Since we're emulating a CALL with exceptions, restore the interrupt
* state to what it was at the exception site.
@@ -260,7 +260,7 @@ DEFINE_IDTENTRY_RAW(exc_invalid_op)
return;
state = irqentry_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
handle_invalid_op(regs);
instrumentation_end();
irqentry_exit(regs, state);
@@ -414,7 +414,7 @@ DEFINE_IDTENTRY_DF(exc_double_fault)
#endif
irqentry_nmi_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
tsk->thread.error_code = error_code;
@@ -690,14 +690,14 @@ DEFINE_IDTENTRY_RAW(exc_int3)
*/
if (user_mode(regs)) {
irqentry_enter_from_user_mode(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
do_int3_user(regs);
instrumentation_end();
irqentry_exit_to_user_mode(regs);
} else {
irqentry_state_t irq_state = irqentry_nmi_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
if (!do_int3(regs))
die("int3", regs, 0);
instrumentation_end();
@@ -896,7 +896,7 @@ static __always_inline void exc_debug_kernel(struct pt_regs *regs,
*/
unsigned long dr7 = local_db_save();
irqentry_state_t irq_state = irqentry_nmi_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
/*
* If something gets miswired and we end up here for a user mode
@@ -975,7 +975,7 @@ static __always_inline void exc_debug_user(struct pt_regs *regs,
*/
irqentry_enter_from_user_mode(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
/*
* Start the virtual/ptrace DR6 value with just the DR_STEP mask
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f2250a32a10ca..676e394f1af5b 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1557,7 +1557,7 @@ DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault)
*/
state = irqentry_enter(regs);
- instrumentation_begin();
+ instrumentation_begin_with_regs(regs);
handle_page_fault(regs, error_code, address);
instrumentation_end();
--
2.35.1.1021.g381101b075-goog
