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 <npig...@gmail.com> Reviewed-by: Nicholas Piggin <npig...@gmail.com> Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com> --- arch/powerpc/kernel/entry_64.S | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index ef8e6615b8ba..c39436706555 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -142,6 +142,7 @@ 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 */ @@ -155,7 +156,7 @@ 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. @@ -309,13 +310,13 @@ 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 -- 2.13.1