queue-4.20/mips-remove-function-size-check-in-get_frame_info.patch

   1 From 890edad3fec5ecb478f7fe3e8ad735a798ec4f4e Mon Sep 17 00:00:00 2001
   2 From: Jun-Ru Chang <jrjang@realtek.com>
   3 Date: Tue, 29 Jan 2019 11:56:07 +0800
   4 Subject: MIPS: Remove function size check in get_frame_info()
   5
   6 [ Upstream commit 2b424cfc69728224fcb5fad138ea7260728e0901 ]
   7
   8 Patch (b6c7a324df37b "MIPS: Fix get_frame_info() handling of
   9 microMIPS function size.") introduces additional function size
  10 check for microMIPS by only checking insn between ip and ip + func_size.
  11 However, func_size in get_frame_info() is always 0 if KALLSYMS is not
  12 enabled. This causes get_frame_info() to return immediately without
  13 calculating correct frame_size, which in turn causes "Can't analyze
  14 schedule() prologue" warning messages at boot time.
  15
  16 This patch removes func_size check, and let the frame_size check run
  17 up to 128 insns for both MIPS and microMIPS.
  18
  19 Signed-off-by: Jun-Ru Chang <jrjang@realtek.com>
  20 Signed-off-by: Tony Wu <tonywu@realtek.com>
  21 Signed-off-by: Paul Burton <paul.burton@mips.com>
  22 Fixes: b6c7a324df37b ("MIPS: Fix get_frame_info() handling of microMIPS function size.")
  23 Cc: <ralf@linux-mips.org>
  24 Cc: <jhogan@kernel.org>
  25 Cc: <macro@mips.com>
  26 Cc: <yamada.masahiro@socionext.com>
  27 Cc: <peterz@infradead.org>
  28 Cc: <mingo@kernel.org>
  29 Cc: <linux-mips@vger.kernel.org>
  30 Cc: <linux-kernel@vger.kernel.org>
  31 Signed-off-by: Sasha Levin <sashal@kernel.org>
  32 ---
  33  arch/mips/kernel/process.c | 7 +++----
  34  1 file changed, 3 insertions(+), 4 deletions(-)
  35
  36 diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
  37 index d4f7fd4550e1..85522c137f19 100644
  38 --- a/arch/mips/kernel/process.c
  39 +++ b/arch/mips/kernel/process.c
  40 @@ -371,7 +371,7 @@ static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
  41  static int get_frame_info(struct mips_frame_info *info)
  42  {
  43         bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
  44 -       union mips_instruction insn, *ip, *ip_end;
  45 +       union mips_instruction insn, *ip;
  46         const unsigned int max_insns = 128;
  47         unsigned int last_insn_size = 0;
  48         unsigned int i;
  49 @@ -384,10 +384,9 @@ static int get_frame_info(struct mips_frame_info *info)
  50         if (!ip)
  51                 goto err;
  52
  53 -       ip_end = (void *)ip + info->func_size;
  54 -
  55 -       for (i = 0; i < max_insns && ip < ip_end; i++) {
  56 +       for (i = 0; i < max_insns; i++) {
  57                 ip = (void *)ip + last_insn_size;
  58 +
  59                 if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
  60                         insn.word = ip->halfword[0] << 16;
  61                         last_insn_size = 2;
  62 --
  63 2.19.1
  64