diff options
Diffstat (limited to 'arch/powerpc/kernel/trace/ftrace_entry.S')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_entry.S | 114 |
1 files changed, 85 insertions, 29 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S index ff376c990308..2c1b24100eca 100644 --- a/arch/powerpc/kernel/trace/ftrace_entry.S +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -33,14 +33,38 @@ * and then arrange for the ftrace function to be called. */ .macro ftrace_regs_entry allregs - /* Save the original return address in A's stack frame */ - PPC_STL r0, LRSAVE(r1) /* Create a minimal stack frame for representing B */ PPC_STLU r1, -STACK_FRAME_MIN_SIZE(r1) /* 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) @@ -54,7 +78,7 @@ .if \allregs == 1 SAVE_GPR(2, r1) - SAVE_GPRS(11, 31, r1) + SAVE_GPRS(13, 31, r1) .else #if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) SAVE_GPR(14, r1) @@ -67,20 +91,15 @@ .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 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) @@ -88,8 +107,8 @@ #endif #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS - /* r7 points to the instruction following the call to ftrace */ - PPC_LL r5, -(MCOUNT_INSN_SIZE*2 + SZL)(r7) + /* 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 */ @@ -105,45 +124,51 @@ /* 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, r7 + mr r15, r11 /* - * We want the ftrace location in the function, but our lr (in r7) + * 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(r7) + lwz r8, MCOUNT_INSN_SIZE(r11) slwi r8, r8, 6 srawi r8, r8, 6 - add r3, r7, r8 + 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 r7, r3, MCOUNT_INSN_SIZE + addi r11, r3, MCOUNT_INSN_SIZE #else /* Calculate ip from nip-4 into r3 for call below */ - subi r3, r7, MCOUNT_INSN_SIZE + subi r3, r11, MCOUNT_INSN_SIZE #endif /* Save NIP as pt_regs->nip */ - PPC_STL r7, _NIP(r1) + PPC_STL r11, _NIP(r1) /* Also save it in B's stackframe header for proper unwind */ - PPC_STL r7, LRSAVE+SWITCH_FRAME_SIZE(r1) + PPC_STL r11, LRSAVE+SWITCH_FRAME_SIZE(r1) #if defined(CONFIG_LIVEPATCH_64) || defined(CONFIG_PPC_FTRACE_OUT_OF_LINE) - mr r14, r7 /* remember old NIP */ + mr r14, r11 /* remember old NIP */ #endif /* Put the original return address in r4 as parent_ip */ @@ -154,14 +179,32 @@ .endm .macro ftrace_regs_exit allregs +#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) - mtctr r3 - #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) @@ -185,12 +228,6 @@ #endif .endif - /* Restore possibly modified LR */ - PPC_LL r0, _LINK(r1) -#ifndef CONFIG_PPC_FTRACE_OUT_OF_LINE - mtlr r0 -#endif - #ifdef CONFIG_PPC64 /* Restore callee's TOC */ ld r2, STK_GOT(r1) @@ -203,8 +240,12 @@ /* Based on the cmpd above, if the NIP was altered handle livepatch */ bne- livepatch_handler #endif + /* 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. @@ -260,6 +301,21 @@ ftrace_no_trace: #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 /* * This function runs in the mcount context, between two functions. As |