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Rao" To: Michael Ellerman Cc: Ananth N Mavinakayanahalli , Masami Hiramatsu , Nicholas Piggin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH v3 3/6] powerpc/64s: Blacklist system_call() and system_call_common() from kprobes Date: Thu, 22 Jun 2017 00:08:39 +0530 In-Reply-To: References: In-Reply-To: References: Message-Id: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Convert some of the symbols into private symbols and blacklist system_call_common() and system_call() from kprobes. We can't take a trap at parts of these functions as either MSR_RI is unset or the kernel stack pointer is not yet setup. Reviewed-by: Masami Hiramatsu Signed-off-by: Naveen N. Rao --- arch/powerpc/kernel/entry_64.S | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index da9486e2fd89..ef8e6615b8ba 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -52,12 +52,11 @@ exception_marker: .section ".text" .align 7 - .globl system_call_common -system_call_common: +_GLOBAL(system_call_common) #ifdef CONFIG_PPC_TRANSACTIONAL_MEM BEGIN_FTR_SECTION extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */ - bne tabort_syscall + bne .Ltabort_syscall END_FTR_SECTION_IFSET(CPU_FTR_TM) #endif andi. r10,r12,MSR_PR @@ -152,9 +151,9 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) CURRENT_THREAD_INFO(r11, r1) ld r10,TI_FLAGS(r11) andi. r11,r10,_TIF_SYSCALL_DOTRACE - bne syscall_dotrace /* does not return */ + bne .Lsyscall_dotrace /* does not return */ cmpldi 0,r0,NR_syscalls - bge- syscall_enosys + bge- .Lsyscall_enosys system_call: /* label this so stack traces look sane */ /* @@ -208,7 +207,7 @@ system_call: /* label this so stack traces look sane */ ld r9,TI_FLAGS(r12) li r11,-MAX_ERRNO andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) - bne- syscall_exit_work + bne- .Lsyscall_exit_work /* If MSR_FP and MSR_VEC are set in user msr, then no need to restore */ li r7,MSR_FP @@ -217,12 +216,12 @@ system_call: /* label this so stack traces look sane */ #endif and r0,r8,r7 cmpd r0,r7 - bne syscall_restore_math + bne .Lsyscall_restore_math .Lsyscall_restore_math_cont: cmpld r3,r11 ld r5,_CCR(r1) - bge- syscall_error + bge- .Lsyscall_error .Lsyscall_error_cont: ld r7,_NIP(r1) BEGIN_FTR_SECTION @@ -248,13 +247,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) RFI b . /* prevent speculative execution */ -syscall_error: +.Lsyscall_error: oris r5,r5,0x1000 /* Set SO bit in CR */ neg r3,r3 std r5,_CCR(r1) b .Lsyscall_error_cont -syscall_restore_math: +.Lsyscall_restore_math: /* * Some initial tests from restore_math to avoid the heavyweight * C code entry and MSR manipulations. @@ -289,7 +288,7 @@ syscall_restore_math: b .Lsyscall_restore_math_cont /* Traced system call support */ -syscall_dotrace: +.Lsyscall_dotrace: bl save_nvgprs addi r3,r1,STACK_FRAME_OVERHEAD bl do_syscall_trace_enter @@ -322,11 +321,11 @@ syscall_dotrace: b .Lsyscall_exit -syscall_enosys: +.Lsyscall_enosys: li r3,-ENOSYS b .Lsyscall_exit -syscall_exit_work: +.Lsyscall_exit_work: #ifdef CONFIG_PPC_BOOK3S li r10,MSR_RI mtmsrd r10,1 /* Restore RI */ @@ -386,7 +385,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) b ret_from_except #ifdef CONFIG_PPC_TRANSACTIONAL_MEM -tabort_syscall: +.Ltabort_syscall: /* Firstly we need to enable TM in the kernel */ mfmsr r10 li r9, 1 @@ -412,6 +411,8 @@ tabort_syscall: rfid b . /* prevent speculative execution */ #endif +_ASM_NOKPROBE_SYMBOL(system_call_common); +_ASM_NOKPROBE_SYMBOL(system_call); /* Save non-volatile GPRs, if not already saved. */ _GLOBAL(save_nvgprs) -- 2.13.1