Merge tag 'powerpc-5.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - A fix for unrecoverable SLB faults in the interrupt exit path,
   introduced by the recent rewrite of interrupt exit in C.

 - Four fixes for our KUAP (Kernel Userspace Access Prevention) support
   on 64-bit. These are all fairly minor with the exception of the
   change to evaluate the get/put_user() arguments before we enable user
   access, which reduces the amount of code we run with user access
   enabled.

 - A fix for our secure boot IMA rules, if enforcement of module
   signatures is enabled at runtime rather than build time.

 - A fix to our 32-bit VDSO clock_getres() which wasn't falling back to
   the syscall for unknown clocks.

 - A build fix for CONFIG_PPC_KUAP_DEBUG on 32-bit BookS, and another
   for 40x.

Thanks to: Christophe Leroy, Hugh Dickins, Nicholas Piggin, Aurelien
Jarno, Mimi Zohar, Nayna Jain.

* tag 'powerpc-5.7-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/40x: Make more space for system call exception
  powerpc/vdso32: Fallback on getres syscall when clock is unknown
  powerpc/32s: Fix build failure with CONFIG_PPC_KUAP_DEBUG
  powerpc/ima: Fix secure boot rules in ima arch policy
  powerpc/64s/kuap: Restore AMR in fast_interrupt_return
  powerpc/64s/kuap: Restore AMR in system reset exception
  powerpc/64/kuap: Move kuap checks out of MSR[RI]=0 regions of exit code
  powerpc/64s: Fix unrecoverable SLB crashes due to preemption check
  powerpc/uaccess: Evaluate macro arguments once, before user access is allowed

Author: torvalds

arch/powerpc/include/asm/book3s/32/kup.h

@@ -75,7 +75,7 @@
 
 .macro kuap_check	current, gpr
 #ifdef CONFIG_PPC_KUAP_DEBUG
-	lwz	\gpr2, KUAP(thread)
+	lwz	\gpr, KUAP(thread)
 999:	twnei	\gpr, 0
 	EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
 #endif

arch/powerpc/include/asm/hw_irq.h

@@ -250,9 +250,27 @@ static inline bool arch_irqs_disabled(void)
 	}								\
 } while(0)
 
+static inline bool __lazy_irq_pending(u8 irq_happened)
+{
+	return !!(irq_happened & ~PACA_IRQ_HARD_DIS);
+}
+
+/*
+ * Check if a lazy IRQ is pending. Should be called with IRQs hard disabled.
+ */
 static inline bool lazy_irq_pending(void)
 {
-	return !!(get_paca()->irq_happened & ~PACA_IRQ_HARD_DIS);
+	return __lazy_irq_pending(get_paca()->irq_happened);
+}
+
+/*
+ * Check if a lazy IRQ is pending, with no debugging checks.
+ * Should be called with IRQs hard disabled.
+ * For use in RI disabled code or other constrained situations.
+ */
+static inline bool lazy_irq_pending_nocheck(void)
+{
+	return __lazy_irq_pending(local_paca->irq_happened);
 }
 
 /*

arch/powerpc/include/asm/uaccess.h

@@ -166,32 +166,44 @@ do {								\
 ({								\
 	long __pu_err;						\
 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
+	__typeof__(*(ptr)) __pu_val = (x);			\
+	__typeof__(size) __pu_size = (size);			\
+								\
 	if (!is_kernel_addr((unsigned long)__pu_addr))		\
 		might_fault();					\
-	__chk_user_ptr(ptr);					\
+	__chk_user_ptr(__pu_addr);				\
 	if (do_allow)								\
-		__put_user_size((x), __pu_addr, (size), __pu_err);		\
+		__put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err);	\
 	else									\
-		__put_user_size_allowed((x), __pu_addr, (size), __pu_err);	\
+		__put_user_size_allowed(__pu_val, __pu_addr, __pu_size, __pu_err); \
+								\
 	__pu_err;						\
 })
 
 #define __put_user_check(x, ptr, size)					\
 ({									\
 	long __pu_err = -EFAULT;					\
 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
+	__typeof__(*(ptr)) __pu_val = (x);				\
+	__typeof__(size) __pu_size = (size);				\
+									\
 	might_fault();							\
-	if (access_ok(__pu_addr, size))			\
-		__put_user_size((x), __pu_addr, (size), __pu_err);	\
+	if (access_ok(__pu_addr, __pu_size))				\
+		__put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
+									\
 	__pu_err;							\
 })
 
 #define __put_user_nosleep(x, ptr, size)			\
 ({								\
 	long __pu_err;						\
 	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
-	__chk_user_ptr(ptr);					\
-	__put_user_size((x), __pu_addr, (size), __pu_err);	\
+	__typeof__(*(ptr)) __pu_val = (x);			\
+	__typeof__(size) __pu_size = (size);			\
+								\
+	__chk_user_ptr(__pu_addr);				\
+	__put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
+								\
 	__pu_err;						\
 })
 
@@ -283,15 +295,18 @@ do {								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
 	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
-	__chk_user_ptr(ptr);					\
+	__typeof__(size) __gu_size = (size);			\
+								\
+	__chk_user_ptr(__gu_addr);				\
 	if (!is_kernel_addr((unsigned long)__gu_addr))		\
 		might_fault();					\
 	barrier_nospec();					\
 	if (do_allow)								\
-		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);		\
+		__get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err);	\
 	else									\
-		__get_user_size_allowed(__gu_val, __gu_addr, (size), __gu_err);	\
+		__get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
 	(x) = (__typeof__(*(ptr)))__gu_val;			\
+								\
 	__gu_err;						\
 })
 
@@ -300,12 +315,15 @@ do {								\
 	long __gu_err = -EFAULT;					\
 	__long_type(*(ptr)) __gu_val = 0;				\
 	__typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
+	__typeof__(size) __gu_size = (size);				\
+									\
 	might_fault();							\
-	if (access_ok(__gu_addr, (size))) {		\
+	if (access_ok(__gu_addr, __gu_size)) {				\
 		barrier_nospec();					\
-		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
+		__get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
 	}								\
 	(x) = (__force __typeof__(*(ptr)))__gu_val;				\
+									\
 	__gu_err;							\
 })
 
@@ -314,10 +332,13 @@ do {								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
 	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
-	__chk_user_ptr(ptr);					\
+	__typeof__(size) __gu_size = (size);			\
+								\
+	__chk_user_ptr(__gu_addr);				\
 	barrier_nospec();					\
-	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
+	__get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
+								\
 	__gu_err;						\
 })
 

arch/powerpc/kernel/entry_64.S

@@ -472,15 +472,17 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
 #ifdef CONFIG_PPC_BOOK3S
 	/*
 	 * If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
-	 * touched, AMR not set, no exit work created, then this can be used.
+	 * touched, no exit work created, then this can be used.
 	 */
 	.balign IFETCH_ALIGN_BYTES
 	.globl fast_interrupt_return
 fast_interrupt_return:
 _ASM_NOKPROBE_SYMBOL(fast_interrupt_return)
+	kuap_check_amr r3, r4
 	ld	r4,_MSR(r1)
 	andi.	r0,r4,MSR_PR
 	bne	.Lfast_user_interrupt_return
+	kuap_restore_amr r3
 	andi.	r0,r4,MSR_RI
 	li	r3,0 /* 0 return value, no EMULATE_STACK_STORE */
 	bne+	.Lfast_kernel_interrupt_return

arch/powerpc/kernel/exceptions-64s.S

@@ -971,6 +971,7 @@ EXC_COMMON_BEGIN(system_reset_common)
 	ld	r10,SOFTE(r1)
 	stb	r10,PACAIRQSOFTMASK(r13)
 
+	kuap_restore_amr r10
 	EXCEPTION_RESTORE_REGS
 	RFI_TO_USER_OR_KERNEL
 

arch/powerpc/kernel/head_40x.S

@@ -344,8 +344,9 @@ _ENTRY(saved_ksp_limit)
 /* 0x0C00 - System Call Exception */
 	START_EXCEPTION(0x0C00,	SystemCall)
 	SYSCALL_ENTRY	0xc00
+/*	Trap_0D is commented out to get more space for system call exception */
 
-	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD)
+/*	EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD) */
 	EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_STD)
 	EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)
 

arch/powerpc/kernel/ima_arch.c

@@ -19,12 +19,12 @@ bool arch_ima_get_secureboot(void)
  * to be stored as an xattr or as an appended signature.
  *
  * To avoid duplicate signature verification as much as possible, the IMA
- * policy rule for module appraisal is added only if CONFIG_MODULE_SIG_FORCE
+ * policy rule for module appraisal is added only if CONFIG_MODULE_SIG
  * is not enabled.
  */
 static const char *const secure_rules[] = {
 	"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
-#ifndef CONFIG_MODULE_SIG_FORCE
+#ifndef CONFIG_MODULE_SIG
 	"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
 #endif
 	NULL
@@ -50,7 +50,7 @@ static const char *const secure_and_trusted_rules[] = {
 	"measure func=KEXEC_KERNEL_CHECK template=ima-modsig",
 	"measure func=MODULE_CHECK template=ima-modsig",
 	"appraise func=KEXEC_KERNEL_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
-#ifndef CONFIG_MODULE_SIG_FORCE
+#ifndef CONFIG_MODULE_SIG
 	"appraise func=MODULE_CHECK appraise_flag=check_blacklist appraise_type=imasig|modsig",
 #endif
 	NULL

arch/powerpc/kernel/syscall_64.c

@@ -35,6 +35,8 @@ notrace long system_call_exception(long r3, long r4, long r5,
 	BUG_ON(!FULL_REGS(regs));
 	BUG_ON(regs->softe != IRQS_ENABLED);
 
+	kuap_check_amr();
+
 	account_cpu_user_entry();
 
 #ifdef CONFIG_PPC_SPLPAR
@@ -47,8 +49,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
 	}
 #endif
 
-	kuap_check_amr();
-
 	/*
 	 * This is not required for the syscall exit path, but makes the
 	 * stack frame look nicer. If this was initialised in the first stack
@@ -117,6 +117,8 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 	unsigned long ti_flags;
 	unsigned long ret = 0;
 
+	kuap_check_amr();
+
 	regs->result = r3;
 
 	/* Check whether the syscall is issued inside a restartable sequence */
@@ -189,7 +191,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 
 	/* This pattern matches prep_irq_for_idle */
 	__hard_EE_RI_disable();
-	if (unlikely(lazy_irq_pending())) {
+	if (unlikely(lazy_irq_pending_nocheck())) {
 		__hard_RI_enable();
 		trace_hardirqs_off();
 		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
@@ -204,8 +206,6 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 	local_paca->tm_scratch = regs->msr;
 #endif
 
-	kuap_check_amr();
-
 	account_cpu_user_exit();
 
 	return ret;
@@ -228,6 +228,8 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 	BUG_ON(!FULL_REGS(regs));
 	BUG_ON(regs->softe != IRQS_ENABLED);
 
+	kuap_check_amr();
+
 	local_irq_save(flags);
 
 again:
@@ -264,7 +266,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 
 	trace_hardirqs_on();
 	__hard_EE_RI_disable();
-	if (unlikely(lazy_irq_pending())) {
+	if (unlikely(lazy_irq_pending_nocheck())) {
 		__hard_RI_enable();
 		trace_hardirqs_off();
 		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
@@ -292,8 +294,6 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 	local_paca->tm_scratch = regs->msr;
 #endif
 
-	kuap_check_amr();
-
 	account_cpu_user_exit();
 
 	return ret;
@@ -313,6 +313,8 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
 	BUG_ON(regs->msr & MSR_PR);
 	BUG_ON(!FULL_REGS(regs));
 
+	kuap_check_amr();
+
 	if (unlikely(*ti_flagsp & _TIF_EMULATE_STACK_STORE)) {
 		clear_bits(_TIF_EMULATE_STACK_STORE, ti_flagsp);
 		ret = 1;
@@ -334,7 +336,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
 
 		trace_hardirqs_on();
 		__hard_EE_RI_disable();
-		if (unlikely(lazy_irq_pending())) {
+		if (unlikely(lazy_irq_pending_nocheck())) {
 			__hard_RI_enable();
 			irq_soft_mask_set(IRQS_ALL_DISABLED);
 			trace_hardirqs_off();

arch/powerpc/kernel/vdso32/gettimeofday.S

@@ -218,11 +218,11 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	blr
 
 	/*
-	 * invalid clock
+	 * syscall fallback
 	 */
 99:
-	li	r3, EINVAL
-	crset	so
+	li	r0,__NR_clock_getres
+	sc
 	blr
   .cfi_endproc
 V_FUNCTION_END(__kernel_clock_getres)