diff options
Diffstat (limited to 'arch/powerpc/kernel/trace/ftrace_64_mprofile.S')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 127 |
1 files changed, 85 insertions, 42 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S index 3f3e81852422..32476a6e4e9c 100644 --- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S +++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S @@ -17,11 +17,10 @@ #include <asm/bug.h> #include <asm/ptrace.h> -#ifdef CONFIG_DYNAMIC_FTRACE /* * - * ftrace_caller() is the function that replaces _mcount() when ftrace is - * active. + * ftrace_caller()/ftrace_regs_caller() is the function that replaces _mcount() + * when ftrace is active. * * We arrive here after a function A calls function B, and we are the trace * function for B. When we enter r1 points to A's stack frame, B has not yet @@ -37,7 +36,7 @@ * Our job is to save the register state into a struct pt_regs (on the stack) * and then arrange for the ftrace function to be called. */ -_GLOBAL(ftrace_caller) +_GLOBAL(ftrace_regs_caller) /* Save the original return address in A's stack frame */ std r0,LRSAVE(r1) @@ -47,6 +46,12 @@ _GLOBAL(ftrace_caller) /* Save all gprs to pt_regs */ SAVE_GPR(0, r1) SAVE_10GPRS(2, r1) + + /* Ok to continue? */ + lbz r3, PACA_FTRACE_ENABLED(r13) + cmpdi r3, 0 + beq ftrace_no_trace + SAVE_10GPRS(12, r1) SAVE_10GPRS(22, r1) @@ -94,44 +99,18 @@ _GLOBAL(ftrace_caller) addi r6, r1 ,STACK_FRAME_OVERHEAD /* ftrace_call(r3, r4, r5, r6) */ -.globl ftrace_call -ftrace_call: +.globl ftrace_regs_call +ftrace_regs_call: bl ftrace_stub nop - /* Load the possibly modified NIP */ - ld r15, _NIP(r1) - + /* Load ctr with the possibly modified NIP */ + ld r3, _NIP(r1) + mtctr r3 #ifdef CONFIG_LIVEPATCH - cmpd r14, r15 /* has NIP been altered? */ -#endif - -#if defined(CONFIG_LIVEPATCH) && defined(CONFIG_KPROBES_ON_FTRACE) - /* NIP has not been altered, skip over further checks */ - beq 1f - - /* Check if there is an active jprobe on us */ - subi r3, r14, 4 - bl __is_active_jprobe - nop - - /* - * If r3 == 1, then this is a kprobe/jprobe. - * else, this is livepatched function. - * - * The conditional branch for livepatch_handler below will use the - * result of this comparison. For kprobe/jprobe, we just need to branch to - * the new NIP, not call livepatch_handler. The branch below is bne, so we - * want CR0[EQ] to be true if this is a kprobe/jprobe. Which means we want - * CR0[EQ] = (r3 == 1). - */ - cmpdi r3, 1 -1: + cmpd r14, r3 /* has NIP been altered? */ #endif - /* Load CTR with the possibly modified NIP */ - mtctr r15 - /* Restore gprs */ REST_GPR(0,r1) REST_10GPRS(2,r1) @@ -149,13 +128,11 @@ ftrace_call: addi r1, r1, SWITCH_FRAME_SIZE #ifdef CONFIG_LIVEPATCH - /* - * Based on the cmpd or cmpdi above, if the NIP was altered and we're - * not on a kprobe/jprobe, then handle livepatch. - */ + /* Based on the cmpd above, if the NIP was altered handle livepatch */ bne- livepatch_handler #endif +ftrace_caller_common: #ifdef CONFIG_FUNCTION_GRAPH_TRACER .globl ftrace_graph_call ftrace_graph_call: @@ -168,6 +145,74 @@ _GLOBAL(ftrace_graph_stub) _GLOBAL(ftrace_stub) blr +ftrace_no_trace: + mflr r3 + mtctr r3 + REST_GPR(3, r1) + addi r1, r1, SWITCH_FRAME_SIZE + mtlr r0 + bctr + +_GLOBAL(ftrace_caller) + /* Save the original return address in A's stack frame */ + std r0, LRSAVE(r1) + + /* Create our stack frame + pt_regs */ + stdu r1, -SWITCH_FRAME_SIZE(r1) + + /* Save all gprs to pt_regs */ + SAVE_8GPRS(3, r1) + + lbz r3, PACA_FTRACE_ENABLED(r13) + cmpdi r3, 0 + beq ftrace_no_trace + + /* Get the _mcount() call site out of LR */ + mflr r7 + std r7, _NIP(r1) + + /* Save callee's TOC in the ABI compliant location */ + std r2, 24(r1) + ld r2, PACATOC(r13) /* get kernel TOC in r2 */ + + addis r3, r2, function_trace_op@toc@ha + addi r3, r3, function_trace_op@toc@l + ld r5, 0(r3) + + /* 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 + + /* Set pt_regs to NULL */ + li r6, 0 + + /* ftrace_call(r3, r4, r5, r6) */ +.globl ftrace_call +ftrace_call: + bl ftrace_stub + nop + + ld r3, _NIP(r1) + mtctr r3 + + /* Restore gprs */ + REST_8GPRS(3,r1) + + /* Restore callee's TOC */ + ld r2, 24(r1) + + /* Pop our stack frame */ + addi r1, r1, SWITCH_FRAME_SIZE + + /* Reload original LR */ + ld r0, LRSAVE(r1) + mtlr r0 + + /* Handle function_graph or go back */ + b ftrace_caller_common + #ifdef CONFIG_LIVEPATCH /* * This function runs in the mcount context, between two functions. As @@ -236,8 +281,6 @@ livepatch_handler: blr #endif /* CONFIG_LIVEPATCH */ -#endif /* CONFIG_DYNAMIC_FTRACE */ - #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(ftrace_graph_caller) stdu r1, -112(r1) |