• Guo Ren's avatar
    riscv: ftrace: Remove wasted nops for !RISCV_ISA_C · 409c8fb2
    Guo Ren authored
    When CONFIG_RISCV_ISA_C=n, -fpatchable-function-entry=8 would generate
    more nops than we expect. Because it treat nop opcode as 0x00000013
    instead of 0x0001.
    
    Dump of assembler code for function dw_pcie_free_msi:
       0xffffffff806fce94 <+0>:     sd      ra,-8(sp)
       0xffffffff806fce98 <+4>:     auipc   ra,0xff90f
       0xffffffff806fce9c <+8>:     jalr    -684(ra) # 0xffffffff8000bbec
    <ftrace_caller>
       0xffffffff806fcea0 <+12>:    ld      ra,-8(sp)
       0xffffffff806fcea4 <+16>:    nop /* wasted */
       0xffffffff806fcea8 <+20>:    nop /* wasted */
       0xffffffff806fceac <+24>:    nop /* wasted */
       0xffffffff806fceb0 <+28>:    nop /* wasted */
       0xffffffff806fceb4 <+0>:     addi    sp,sp,-48
       0xffffffff806fceb8 <+4>:     sd      s0,32(sp)
       0xffffffff806fcebc <+8>:     sd      s1,24(sp)
       0xffffffff806fcec0 <+12>:    sd      s2,16(sp)
       0xffffffff806fcec4 <+16>:    sd      s3,8(sp)
       0xffffffff806fcec8 <+20>:    sd      ra,40(sp)
       0xffffffff806fcecc <+24>:    addi    s0,sp,48
    Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
    Signed-off-by: default avatarGuo Ren <guoren@kernel.org>
    Link: https://lore.kernel.org/r/20230112090603.1295340-3-guoren@kernel.org
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
    409c8fb2
Makefile 5.07 KB