diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2020-11-12 15:54:47 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-20 19:19:11 +0100 |
| commit | c9343637d6b265127dfe37cd7e09eb6feac03032 (patch) | |
| tree | 939af3da833da49e38d422644893064928ea377a /arch/s390/kernel/mcount.S | |
| parent | 73045a08cf5549cc7dee14463431fbeb2134dd67 (diff) | |
s390/ftrace: assume -mhotpatch or -mrecord-mcount always available
Currently the kernel minimal compiler requirement is gcc 4.9 or
clang 10.0.1.
* gcc -mhotpatch option is supported since 4.8.
* A combination of -pg -mrecord-mcount -mnop-mcount -mfentry flags is
supported since gcc 9 and since clang 10.
Drop support for old -pg function prologues. Which leaves binary
compatible -mhotpatch / -mnop-mcount -mfentry prologues in a form:
brcl 0,0
Which are also do not require initial nop optimization / conversion and
presence of _mcount symbol.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/mcount.S')
| -rw-r--r-- | arch/s390/kernel/mcount.S | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S index 7458dcfd6464..faf64c2f90f5 100644 --- a/arch/s390/kernel/mcount.S +++ b/arch/s390/kernel/mcount.S @@ -33,11 +33,6 @@ ENDPROC(ftrace_stub) #define TRACED_FUNC_FRAME_SIZE STACK_FRAME_OVERHEAD #endif -ENTRY(_mcount) - BR_EX %r14 -ENDPROC(_mcount) -EXPORT_SYMBOL(_mcount) - ENTRY(ftrace_caller) .globl ftrace_regs_caller .set ftrace_regs_caller,ftrace_caller @@ -46,9 +41,6 @@ ENTRY(ftrace_caller) ipm %r14 # don't put any instructions sllg %r14,%r14,16 # clobbering CC before this point lgr %r1,%r15 -#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)) - aghi %r0,MCOUNT_RETURN_FIXUP -#endif # allocate stack frame for ftrace_caller to contain traced function aghi %r15,-TRACED_FUNC_FRAME_SIZE stg %r1,__SF_BACKCHAIN(%r15) |