diff options
Diffstat (limited to 'arch/powerpc/kernel/trace/ftrace_entry.S')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_entry.S | 244 |
1 files changed, 197 insertions, 47 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S index 76dbe9fd2c0f..2c1b24100eca 100644 --- a/arch/powerpc/kernel/trace/ftrace_entry.S +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -39,13 +39,37 @@ /* Create our stack frame + pt_regs */ PPC_STLU r1,-SWITCH_FRAME_SIZE(r1) + .if \allregs == 1 + SAVE_GPRS(11, 12, r1) + .endif + + /* Get the _mcount() call site out of LR */ + mflr r11 + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Load the ftrace_op */ + PPC_LL r12, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + + /* Load direct_call from the ftrace_op */ + PPC_LL r12, FTRACE_OPS_DIRECT_CALL(r12) + PPC_LCMPI r12, 0 + .if \allregs == 1 + bne .Lftrace_direct_call_regs + .else + bne .Lftrace_direct_call + .endif +#endif + + /* Save the previous LR in pt_regs->link */ + PPC_STL r0, _LINK(r1) + /* Also save it in A's stack frame */ + PPC_STL r0, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE+LRSAVE(r1) + /* Save all gprs to pt_regs */ SAVE_GPR(0, r1) SAVE_GPRS(3, 10, r1) #ifdef CONFIG_PPC64 - /* Save the original return address in A's stack frame */ - std r0, LRSAVE+SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE(r1) /* Ok to continue? */ lbz r3, PACA_FTRACE_ENABLED(r13) cmpdi r3, 0 @@ -54,9 +78,9 @@ .if \allregs == 1 SAVE_GPR(2, r1) - SAVE_GPRS(11, 31, r1) + SAVE_GPRS(13, 31, r1) .else -#ifdef CONFIG_LIVEPATCH_64 +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) SAVE_GPR(14, r1) #endif .endif @@ -67,80 +91,143 @@ .if \allregs == 1 /* Load special regs for save below */ + mfcr r7 mfmsr r8 mfctr r9 mfxer r10 - mfcr r11 .else /* Clear MSR to flag as ftrace_caller versus frace_regs_caller */ li r8, 0 .endif - /* Get the _mcount() call site out of LR */ - mflr r7 - /* Save it as pt_regs->nip */ - PPC_STL r7, _NIP(r1) - /* Also save it in B's stackframe header for proper unwind */ - PPC_STL r7, LRSAVE+SWITCH_FRAME_SIZE(r1) - /* Save the read LR in pt_regs->link */ - PPC_STL r0, _LINK(r1) - #ifdef CONFIG_PPC64 /* Save callee's TOC in the ABI compliant location */ std r2, STK_GOT(r1) LOAD_PACA_TOC() /* get kernel TOC in r2 */ +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + /* r11 points to the instruction following the call to ftrace */ + PPC_LL r5, -(MCOUNT_INSN_SIZE*2 + SZL)(r11) + PPC_LL r12, FTRACE_OPS_FUNC(r5) + mtctr r12 +#else /* !CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS */ +#ifdef CONFIG_PPC64 LOAD_REG_ADDR(r3, function_trace_op) ld r5,0(r3) #else lis r3,function_trace_op@ha lwz r5,function_trace_op@l(r3) #endif - -#ifdef CONFIG_LIVEPATCH_64 - mr r14, r7 /* remember old NIP */ #endif - /* Calculate ip from nip-4 into r3 for call below */ - subi r3, r7, MCOUNT_INSN_SIZE - - /* Put the original return address in r4 as parent_ip */ - mr r4, r0 - /* Save special regs */ PPC_STL r8, _MSR(r1) .if \allregs == 1 + PPC_STL r7, _CCR(r1) PPC_STL r9, _CTR(r1) PPC_STL r10, _XER(r1) - PPC_STL r11, _CCR(r1) .endif +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Clear orig_gpr3 to later detect ftrace_direct call */ + li r7, 0 + PPC_STL r7, ORIG_GPR3(r1) +#endif + +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Save our real return address in nvr for return */ + .if \allregs == 0 + SAVE_GPR(15, r1) + .endif + mr r15, r11 + /* + * We want the ftrace location in the function, but our lr (in r11) + * points at the 'mtlr r0' instruction in the out of line stub. To + * recover the ftrace location, we read the branch instruction in the + * stub, and adjust our lr by the branch offset. + * + * See ftrace_init_ool_stub() for the profile sequence. + */ + lwz r8, MCOUNT_INSN_SIZE(r11) + slwi r8, r8, 6 + srawi r8, r8, 6 + add r3, r11, r8 + /* + * Override our nip to point past the branch in the original function. + * This allows reliable stack trace and the ftrace stack tracer to work as-is. + */ + addi r11, r3, MCOUNT_INSN_SIZE +#else + /* Calculate ip from nip-4 into r3 for call below */ + subi r3, r11, MCOUNT_INSN_SIZE +#endif + + /* Save NIP as pt_regs->nip */ + PPC_STL r11, _NIP(r1) + /* Also save it in B's stackframe header for proper unwind */ + PPC_STL r11, LRSAVE+SWITCH_FRAME_SIZE(r1) +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) + mr r14, r11 /* remember old NIP */ +#endif + + /* Put the original return address in r4 as parent_ip */ + mr r4, r0 + /* Load &pt_regs in r6 for call below */ addi r6, r1, STACK_INT_FRAME_REGS .endm .macro ftrace_regs_exit allregs - /* Load ctr with the possibly modified NIP */ - PPC_LL r3, _NIP(r1) +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + /* Check orig_gpr3 to detect ftrace_direct call */ + PPC_LL r3, ORIG_GPR3(r1) + PPC_LCMPI cr1, r3, 0 mtctr r3 +#endif + /* Restore possibly modified LR */ + PPC_LL r0, _LINK(r1) + +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + /* Load ctr with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) #ifdef CONFIG_LIVEPATCH_64 cmpd r14, r3 /* has NIP been altered? */ #endif +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + beq cr1,2f + mtlr r3 + b 3f +#endif +2: mtctr r3 + mtlr r0 +3: + +#else /* !CONFIG_PPC_FTRACE_OUT_OF_LINE */ + /* Load LR with the possibly modified NIP */ + PPC_LL r3, _NIP(r1) + cmpd r14, r3 /* has NIP been altered? */ + bne- 1f + + mr r3, r15 + .if \allregs == 0 + REST_GPR(15, r1) + .endif +1: mtlr r3 +#endif + /* Restore gprs */ .if \allregs == 1 REST_GPRS(2, 31, r1) .else REST_GPRS(3, 10, r1) -#ifdef CONFIG_LIVEPATCH_64 +#if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) REST_GPR(14, r1) #endif .endif - /* Restore possibly modified LR */ - PPC_LL r0, _LINK(r1) - mtlr r0 - #ifdef CONFIG_PPC64 /* Restore callee's TOC */ ld r2, STK_GOT(r1) @@ -153,23 +240,46 @@ /* Based on the cmpd above, if the NIP was altered handle livepatch */ bne- livepatch_handler #endif - bctr /* jump after _mcount site */ + + /* jump after _mcount site */ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS + bnectr cr1 +#endif + /* + * Return with blr to keep the link stack balanced. The function profiling sequence + * uses 'mtlr r0' to restore LR. + */ + blr +#else + bctr +#endif .endm -_GLOBAL(ftrace_regs_caller) - ftrace_regs_entry 1 - /* ftrace_call(r3, r4, r5, r6) */ +.macro ftrace_regs_func allregs +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS + bctrl +#else + .if \allregs == 1 .globl ftrace_regs_call ftrace_regs_call: + .else +.globl ftrace_call +ftrace_call: + .endif + /* ftrace_call(r3, r4, r5, r6) */ bl ftrace_stub +#endif +.endm + +_GLOBAL(ftrace_regs_caller) + ftrace_regs_entry 1 + ftrace_regs_func 1 ftrace_regs_exit 1 _GLOBAL(ftrace_caller) ftrace_regs_entry 0 - /* ftrace_call(r3, r4, r5, r6) */ -.globl ftrace_call -ftrace_call: - bl ftrace_stub + ftrace_regs_func 0 ftrace_regs_exit 0 _GLOBAL(ftrace_stub) @@ -177,6 +287,11 @@ _GLOBAL(ftrace_stub) #ifdef CONFIG_PPC64 ftrace_no_trace: +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE + REST_GPR(3, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + blr +#else mflr r3 mtctr r3 REST_GPR(3, r1) @@ -184,6 +299,22 @@ ftrace_no_trace: mtlr r0 bctr #endif +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS +.Lftrace_direct_call_regs: + mtctr r12 + REST_GPRS(11, 12, r1) + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +.Lftrace_direct_call: + mtctr r12 + addi r1, r1, SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE + bctr +SYM_FUNC_START(ftrace_stub_direct_tramp) + blr +SYM_FUNC_END(ftrace_stub_direct_tramp) +#endif #ifdef CONFIG_LIVEPATCH_64 /* @@ -194,11 +325,17 @@ ftrace_no_trace: * We get here when a function A, calls another function B, but B has * been live patched with a new function C. * - * On entry: - * - we have no stack frame and can not allocate one + * On entry, we have no stack frame and can not allocate one. + * + * With PPC_FTRACE_OUT_OF_LINE=n, on entry: * - LR points back to the original caller (in A) * - CTR holds the new NIP in C * - r0, r11 & r12 are free + * + * With PPC_FTRACE_OUT_OF_LINE=y, on entry: + * - r0 points back to the original caller (in A) + * - LR holds the new NIP in C + * - r11 & r12 are free */ livepatch_handler: ld r12, PACA_THREAD_INFO(r13) @@ -208,18 +345,23 @@ livepatch_handler: addi r11, r11, 24 std r11, TI_livepatch_sp(r12) - /* Save toc & real LR on livepatch stack */ - std r2, -24(r11) - mflr r12 - std r12, -16(r11) - /* Store stack end marker */ lis r12, STACK_END_MAGIC@h ori r12, r12, STACK_END_MAGIC@l std r12, -8(r11) - /* Put ctr in r12 for global entry and branch there */ + /* Save toc & real LR on livepatch stack */ + std r2, -24(r11) +#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE + mflr r12 + std r12, -16(r11) mfctr r12 +#else + std r0, -16(r11) + mflr r12 + /* Put ctr in r12 for global entry and branch there */ + mtctr r12 +#endif bctrl /* @@ -308,6 +450,14 @@ _GLOBAL(return_to_handler) blr #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ +#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE +SYM_DATA(ftrace_ool_stub_text_count, .long CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE) + +SYM_START(ftrace_ool_stub_text, SYM_L_GLOBAL, .balign SZL) + .space CONFIG_PPC_FTRACE_OUT_OF_LINE_NUM_RESERVE * FTRACE_OOL_STUB_SIZE +SYM_CODE_END(ftrace_ool_stub_text) +#endif + .pushsection ".tramp.ftrace.text","aw",@progbits; .globl ftrace_tramp_text ftrace_tramp_text: |