[GIT PULL] objtool fixes

From: Ingo Molnar
Date: Thu Jun 24 2021 - 02:54:47 EST


Linus,

Please pull the latest objtool/urgent git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-urgent-2021-06-24

# HEAD: 49faa77759b211fff344898edc23bb780707fff5 locking/lockdep: Improve noinstr vs errors

Address a number of objtool warnings that got reported.

No change in behavior intended, but code generation might be
impacted by:

1f008d46f124: ("x86: Always inline task_size_max()")

Thanks,

Ingo

------------------>
Peter Zijlstra (6):
objtool/x86: Ignore __x86_indirect_alt_* symbols
x86/entry: Fix noinstr fail in __do_fast_syscall_32()
x86/xen: Fix noinstr fail in xen_pv_evtchn_do_upcall()
x86/xen: Fix noinstr fail in exc_xen_unknown_trap()
x86: Always inline task_size_max()
locking/lockdep: Improve noinstr vs errors


arch/x86/entry/common.c | 5 +++--
arch/x86/include/asm/page_64.h | 2 +-
arch/x86/lib/retpoline.S | 4 ++++
arch/x86/xen/enlighten_pv.c | 2 ++
include/linux/debug_locks.h | 2 ++
kernel/locking/lockdep.c | 4 +++-
lib/debug_locks.c | 2 +-
7 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 7b2542b13ebd..04bce95bc7e3 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -130,8 +130,8 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs)
/* User code screwed up. */
regs->ax = -EFAULT;

- instrumentation_end();
local_irq_disable();
+ instrumentation_end();
irqentry_exit_to_user_mode(regs);
return false;
}
@@ -269,15 +269,16 @@ __visible noinstr void xen_pv_evtchn_do_upcall(struct pt_regs *regs)
irqentry_state_t state = irqentry_enter(regs);
bool inhcall;

+ instrumentation_begin();
run_sysvec_on_irqstack_cond(__xen_pv_evtchn_do_upcall, regs);

inhcall = get_and_clear_inhcall();
if (inhcall && !WARN_ON_ONCE(state.exit_rcu)) {
- instrumentation_begin();
irqentry_exit_cond_resched();
instrumentation_end();
restore_inhcall(inhcall);
} else {
+ instrumentation_end();
irqentry_exit(regs, state);
}
}
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index ca840fec7776..4bde0dc66100 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -75,7 +75,7 @@ void copy_page(void *to, void *from);
*
* With page table isolation enabled, we map the LDT in ... [stay tuned]
*/
-static inline unsigned long task_size_max(void)
+static __always_inline unsigned long task_size_max(void)
{
unsigned long ret;

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 4d32cb06ffd5..ec9922cba30a 100644
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -58,12 +58,16 @@ SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg)
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_call_\reg)

+STACK_FRAME_NON_STANDARD(__x86_indirect_alt_call_\reg)
+
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg)
ANNOTATE_RETPOLINE_SAFE
1: jmp *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_jmp_\reg)

+STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg)
+
.endm

/*
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index e87699aa2dc8..03149422dce2 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -592,8 +592,10 @@ DEFINE_IDTENTRY_RAW(xenpv_exc_debug)
DEFINE_IDTENTRY_RAW(exc_xen_unknown_trap)
{
/* This should never happen and there is no way to handle it. */
+ instrumentation_begin();
pr_err("Unknown trap in Xen PV mode.");
BUG();
+ instrumentation_end();
}

#ifdef CONFIG_X86_MCE
diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 2915f56ad421..edb5c186b0b7 100644
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -27,8 +27,10 @@ extern int debug_locks_off(void);
int __ret = 0; \
\
if (!oops_in_progress && unlikely(c)) { \
+ instrumentation_begin(); \
if (debug_locks_off() && !debug_locks_silent) \
WARN(1, "DEBUG_LOCKS_WARN_ON(%s)", #c); \
+ instrumentation_end(); \
__ret = 1; \
} \
__ret; \
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 7641bd407239..e32313072506 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -843,7 +843,7 @@ static int count_matching_names(struct lock_class *new_class)
}

/* used from NMI context -- must be lockless */
-static __always_inline struct lock_class *
+static noinstr struct lock_class *
look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
{
struct lockdep_subclass_key *key;
@@ -851,12 +851,14 @@ look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
struct lock_class *class;

if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+ instrumentation_begin();
debug_locks_off();
printk(KERN_ERR
"BUG: looking up invalid subclass: %u\n", subclass);
printk(KERN_ERR
"turning off the locking correctness validator.\n");
dump_stack();
+ instrumentation_end();
return NULL;
}

diff --git a/lib/debug_locks.c b/lib/debug_locks.c
index 06d3135bd184..a75ee30b77cb 100644
--- a/lib/debug_locks.c
+++ b/lib/debug_locks.c
@@ -36,7 +36,7 @@ EXPORT_SYMBOL_GPL(debug_locks_silent);
/*
* Generic 'turn off all lock debugging' function:
*/
-noinstr int debug_locks_off(void)
+int debug_locks_off(void)
{
if (debug_locks && __debug_locks_off()) {
if (!debug_locks_silent) {