From 31197d3a0f1caeb60fb01f6755e28347e4f44037 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 16:13:55 +0200 Subject: objtool/x86: Ignore __x86_indirect_alt_* symbols Because the __x86_indirect_alt* symbols are just that, objtool will try and validate them as regular symbols, instead of the alternative replacements that they are. This goes sideways for FRAME_POINTER=y builds; which generate a fair amount of warnings. Fixes: 9bc0bb50727c ("objtool/x86: Rewrite retpoline thunk calls") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/YNCgxwLBiK9wclYJ@hirez.programming.kicks-ass.net --- arch/x86/lib/retpoline.S | 4 ++++ 1 file changed, 4 insertions(+) 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 /* -- cgit v1.2.3 From 240001d4e3041832e8a2654adc3ccf1683132b92 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 13:12:34 +0200 Subject: x86/entry: Fix noinstr fail in __do_fast_syscall_32() Fix: vmlinux.o: warning: objtool: __do_fast_syscall_32()+0xf5: call to trace_hardirqs_off() leaves .noinstr.text section Fixes: 5d5675df792f ("x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210621120120.467898710@infradead.org --- arch/x86/entry/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 7b2542b13ebd..a6bf516257ec 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; } -- cgit v1.2.3 From 84e60065df9ef03759115a7e48c04bbc0d292165 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 13:12:35 +0200 Subject: x86/xen: Fix noinstr fail in xen_pv_evtchn_do_upcall() Fix: vmlinux.o: warning: objtool: xen_pv_evtchn_do_upcall()+0x23: call to irq_enter_rcu() leaves .noinstr.text section Fixes: 359f01d1816f ("x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210621120120.532960208@infradead.org --- arch/x86/entry/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index a6bf516257ec..04bce95bc7e3 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -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); } } -- cgit v1.2.3 From 4c9c26f1e67648f41f28f8c997c5c9467a3dbbe4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 13:12:36 +0200 Subject: x86/xen: Fix noinstr fail in exc_xen_unknown_trap() Fix: vmlinux.o: warning: objtool: exc_xen_unknown_trap()+0x7: call to printk() leaves .noinstr.text section Fixes: 2e92493637a0 ("x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210621120120.606560778@infradead.org --- arch/x86/xen/enlighten_pv.c | 2 ++ 1 file changed, 2 insertions(+) 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 -- cgit v1.2.3 From 1f008d46f1243899d27fd034ab5c41985bd16cee Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 13:12:37 +0200 Subject: x86: Always inline task_size_max() Fix: vmlinux.o: warning: objtool: handle_bug()+0x10: call to task_size_max() leaves .noinstr.text section When #UD isn't a BUG, we shouldn't violate noinstr (we'll still probably die, but that's another story). Fixes: 025768a966a3 ("x86/cpu: Use alternative to generate the TASK_SIZE_MAX constant") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210621120120.682468274@infradead.org --- arch/x86/include/asm/page_64.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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; -- cgit v1.2.3 From 49faa77759b211fff344898edc23bb780707fff5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Jun 2021 13:12:38 +0200 Subject: locking/lockdep: Improve noinstr vs errors Better handle the failure paths. vmlinux.o: warning: objtool: debug_locks_off()+0x23: call to console_verbose() leaves .noinstr.text section vmlinux.o: warning: objtool: debug_locks_off()+0x19: call to __kasan_check_write() leaves .noinstr.text section debug_locks_off+0x19/0x40: instrument_atomic_write at include/linux/instrumented.h:86 (inlined by) __debug_locks_off at include/linux/debug_locks.h:17 (inlined by) debug_locks_off at lib/debug_locks.c:41 Fixes: 6eebad1ad303 ("lockdep: __always_inline more for noinstr") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210621120120.784404944@infradead.org --- include/linux/debug_locks.h | 2 ++ kernel/locking/lockdep.c | 4 +++- lib/debug_locks.c | 2 +- 3 files changed, 6 insertions(+), 2 deletions(-) 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) { -- cgit v1.2.3