powerpc/mm: Mark get_slice_psize() & slice_addr_is_low() as notrace

commit 91a063c956084fb21cf2523bce6892514e3f1799 upstream.

These slice routines are called from the SLB miss handler, which can
lead to warnings from the IRQ code, because we have not reconciled the
IRQ state properly:

  WARNING: CPU: 72 PID: 30150 at arch/powerpc/kernel/irq.c:258 arch_local_irq_restore.part.0+0xcc/0x100
  Modules linked in:
  CPU: 72 PID: 30150 Comm: ftracetest Not tainted 5.5.0-rc2-gcc9x-g7e0165b2f1a9 #1
  NIP:  c00000000001d83c LR: c00000000029ab90 CTR: c00000000026cf90
  REGS: c0000007eee3b960 TRAP: 0700   Not tainted  (5.5.0-rc2-gcc9x-g7e0165b2f1a9)
  MSR:  8000000000021033 <SF,ME,IR,DR,RI,LE>  CR: 22242844  XER: 20000000
  CFAR: c00000000001d780 IRQMASK: 0
  ...
  NIP arch_local_irq_restore.part.0+0xcc/0x100
  LR  trace_graph_entry+0x270/0x340
  Call Trace:
    trace_graph_entry+0x254/0x340 (unreliable)
    function_graph_enter+0xe4/0x1a0
    prepare_ftrace_return+0xa0/0x130
    ftrace_graph_caller+0x44/0x94	# (get_slice_psize())
    slb_allocate_user+0x7c/0x100
    do_slb_fault+0xf8/0x300
    instruction_access_slb_common+0x140/0x180

Fixes: 48e7b7695745 ("powerpc/64s/hash: Convert SLB miss handlers to C")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191221121337.4894-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c
index 42bbcd47cc85ffb1f6900a3ec045db5a2561138d..dffe1a45b6ed4df131f8e18c6cbe851bd1b3fded 100644 (file)
--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -50,7 +50,7 @@ static void slice_print_mask(const char *label, const struct slice_mask *mask) {
 
 #endif
 
-static inline bool slice_addr_is_low(unsigned long addr)
+static inline notrace bool slice_addr_is_low(unsigned long addr)
 {
        u64 tmp = (u64)addr;
 
@@ -659,7 +659,7 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
                                       mm_ctx_user_psize(&current->mm->context), 1);
 }
 
-unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
+unsigned int notrace get_slice_psize(struct mm_struct *mm, unsigned long addr)
 {
        unsigned char *psizes;
        int index, mask_index;