Merge tag 'powerpc-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - On 32-bit fix overread/overwrite of thread_struct via ptrace
   PEEK/POKE.

 - Fix softirqs not switching to the softirq stack since we moved
   irq_exit().

 - Force thread size increase when KASAN is enabled to avoid stack
   overflows.

 - On Book3s 64 mark more code as not to be instrumented by KASAN to
   avoid crashes.

 - Exempt __get_wchan() from KASAN checking, as it's inherently racy.

 - Fix a recently introduced crash in the papr_scm driver in some
   configurations.

 - Remove include of <generated/compile.h> which is forbidden.

Thanks to Ariel Miculas, Chen Jingwen, Christophe Leroy, Erhard Furtner,
He Ying, Kees Cook, Masahiro Yamada, Nageswara R Sastry, Paul Mackerras,
Sachin Sant, Vaibhav Jain, and Wanming Hu.

* tag 'powerpc-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32: Fix overread/overwrite of thread_struct via ptrace
  powerpc/book3e: get rid of #include <generated/compile.h>
  powerpc/kasan: Force thread size increase with KASAN
  powerpc/papr_scm: don't requests stats with '0' sized stats buffer
  powerpc: Don't select HAVE_IRQ_EXIT_ON_IRQ_STACK
  powerpc/kasan: Silence KASAN warnings in __get_wchan()
  powerpc/kasan: Mark more real-mode code as not to be instrumented

5 files changed, 23 insertions, 10 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2e2a2a9bcf43..f91f0f29a566 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -37,6 +37,8 @@ KASAN_SANITIZE_paca.o := n
 KASAN_SANITIZE_setup_64.o := n
 KASAN_SANITIZE_mce.o := n
 KASAN_SANITIZE_mce_power.o := n
+KASAN_SANITIZE_udbg.o := n
+KASAN_SANITIZE_udbg_16550.o := n
 
 # we have to be particularly careful in ppc64 to exclude code that
 # runs with translations off, as we cannot access the shadow with
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b62046bf3bb8..ee0433809621 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2158,12 +2158,12 @@ static unsigned long ___get_wchan(struct task_struct *p)
 		return 0;
 
 	do {
-		sp = *(unsigned long *)sp;
+		sp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
 		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
 		    task_is_running(p))
 			return 0;
 		if (count > 0) {
-			ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
+			ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]);
 			if (!in_sched_functions(ip))
 				return ip;
 		}
diff --git a/arch/powerpc/kernel/ptrace/ptrace-fpu.c b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
index 5dca19361316..09c49632bfe5 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-fpu.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-fpu.c
@@ -17,9 +17,13 @@ int ptrace_get_fpr(struct task_struct *child, int index, unsigned long *data)
 
 #ifdef CONFIG_PPC_FPU_REGS
 	flush_fp_to_thread(child);
-	if (fpidx < (PT_FPSCR - PT_FPR0))
-		memcpy(data, &child->thread.TS_FPR(fpidx), sizeof(long));
-	else
+	if (fpidx < (PT_FPSCR - PT_FPR0)) {
+		if (IS_ENABLED(CONFIG_PPC32))
+			// On 32-bit the index we are passed refers to 32-bit words
+			*data = ((u32 *)child->thread.fp_state.fpr)[fpidx];
+		else
+			memcpy(data, &child->thread.TS_FPR(fpidx), sizeof(long));
+	} else
 		*data = child->thread.fp_state.fpscr;
 #else
 	*data = 0;
@@ -39,9 +43,13 @@ int ptrace_put_fpr(struct task_struct *child, int index, unsigned long data)
 
 #ifdef CONFIG_PPC_FPU_REGS
 	flush_fp_to_thread(child);
-	if (fpidx < (PT_FPSCR - PT_FPR0))
-		memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long));
-	else
+	if (fpidx < (PT_FPSCR - PT_FPR0)) {
+		if (IS_ENABLED(CONFIG_PPC32))
+			// On 32-bit the index we are passed refers to 32-bit words
+			((u32 *)child->thread.fp_state.fpr)[fpidx] = data;
+		else
+			memcpy(&child->thread.TS_FPR(fpidx), &data, sizeof(long));
+	} else
 		child->thread.fp_state.fpscr = data;
 #endif
 
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
index 4d2dc22d4a2d..5d7a72b41ae7 100644
--- a/arch/powerpc/kernel/ptrace/ptrace.c
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -444,4 +444,7 @@ void __init pt_regs_check(void)
 	 * real registers.
 	 */
 	BUILD_BUG_ON(PT_DSCR < sizeof(struct user_pt_regs) / sizeof(unsigned long));
+
+	// ptrace_get/put_fpr() rely on PPC32 and VSX being incompatible
+	BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_VSX));
 }
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 9bb43aa53d43..a6fce3106e02 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -993,8 +993,8 @@ int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
  *
  * Return: A pointer to the specified errorlog or NULL if not found.
  */
-struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
-					      uint16_t section_id)
+noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
+						      uint16_t section_id)
 {
 	struct rtas_ext_event_log_v6 *ext_log =
 		(struct rtas_ext_event_log_v6 *)log->buffer;