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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2017-06-29 23:19:17 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-07-03 23:12:00 +1000 |
| commit | 266de3a842d70b481ef1dac487acfad1240deb7e (patch) | |
| tree | a449d0478c0d9d357e3d579eb6e207ffd2e0c937 | |
| parent | cf7d6fb0672668690ba235280698c9aa6a81010a (diff) | |
| download | linux-stable-266de3a842d70b481ef1dac487acfad1240deb7e.tar.gz linux-stable-266de3a842d70b481ef1dac487acfad1240deb7e.tar.bz2 linux-stable-266de3a842d70b481ef1dac487acfad1240deb7e.zip | |
powerpc/64s: Move system_call() symbol to just after setting MSR_EE
It is common to get a PMU interrupt right after the mtmsr instruction that
enables interrupts. Due to this, the stack trace profile gets needlessly split
across system_call_common() and system_call().
Previously, system_call() symbol was at the current place to hide a few
earlier symbols which have since been made private or removed entirely.
So, let's move system_call() slightly higher up, right after the mtmsr
instruction that enables interrupts. Convert existing references to
system_call to a local syscall symbol.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 410e19295259..e5cf98d755db 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -143,6 +143,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) mtmsrd r11,1 #endif /* CONFIG_PPC_BOOK3E */ +system_call: /* label this so stack traces look sane */ /* We do need to set SOFTE in the stack frame or the return * from interrupt will be painful */ @@ -156,7 +157,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) cmpldi 0,r0,NR_syscalls bge- .Lsyscall_enosys -system_call: /* label this so stack traces look sane */ +.Lsyscall: /* * Need to vector to 32 Bit or default sys_call_table here, * based on caller's run-mode / personality. @@ -310,13 +311,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) ld r7,GPR7(r1) ld r8,GPR8(r1) - /* Repopulate r9 and r10 for the system_call path */ + /* Repopulate r9 and r10 for the syscall path */ addi r9,r1,STACK_FRAME_OVERHEAD CURRENT_THREAD_INFO(r10, r1) ld r10,TI_FLAGS(r10) cmpldi r0,NR_syscalls - blt+ system_call + blt+ .Lsyscall /* Return code is already in r3 thanks to do_syscall_trace_enter() */ b .Lsyscall_exit |