* [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation
@ 2015-06-11 9:53 Torsten Duwe
2015-06-11 9:58 ` [PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe
` (4 more replies)
0 siblings, 5 replies; 27+ messages in thread
From: Torsten Duwe @ 2015-06-11 9:53 UTC (permalink / raw)
To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel
Hi again,
with the previous submission I was too much into the details to
state a few obvious things. Now with nicer explanations and
changelog.
Torsten
^ permalink raw reply [flat|nested] 27+ messages in thread* [PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe @ 2015-06-11 9:58 ` Torsten Duwe 2015-06-11 9:59 ` [PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe ` (3 subsequent siblings) 4 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-11 9:58 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel Implement FTRACE_WITH_REGS for powerpc64, on ELF ABI v2. Initial work started by Vojtech Pavlik, used with permission. * arch/powerpc/kernel/entry_64.S: - enhance _mcount with a stub to test (ftrace_trace_function == &ftrace_stub) as suggested in Documentation/trace/ftrace-design.txt (for reference only, patched out at runtime) - Implement an effective ftrace_caller that works from within the kernel binary as well as from modules. * arch/powerpc/kernel/ftrace.c: - be prepared to deal with ppc64 ELV ABI v2, especially calls to _mcount that result from gcc -mprofile-kernel * arch/powerpc/kernel/module_64.c: - do not save the TOC pointer on the trampoline when the destination is ftrace_caller. This trampoline jump happens from a function prologue before a new stack frame is set up, so bad things may happen otherwise... - relax is_module_trampoline() to recognise the modified trampoline. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/include/asm/ftrace.h | 5 + arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- arch/powerpc/kernel/module_64.c | 33 ++++++++++- 4 files changed, 186 insertions(+), 31 deletions(-) -- diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index e366187..6111191 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -46,6 +46,8 @@ extern void _mcount(void); #ifdef CONFIG_DYNAMIC_FTRACE +# define FTRACE_ADDR ((unsigned long)ftrace_caller+8) +# define FTRACE_REGS_ADDR FTRACE_ADDR static inline unsigned long ftrace_call_adjust(unsigned long addr) { /* reloction of mcount call site is the same as the address */ @@ -58,6 +60,9 @@ struct dyn_arch_ftrace { #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* __ASSEMBLY__ */ +#ifdef CONFIG_DYNAMIC_FTRACE +#define ARCH_SUPPORTS_FTRACE_OPS 1 +#endif #endif #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) && !defined(__ASSEMBLY__) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index d180caf..a4132ef 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1152,32 +1152,107 @@ _GLOBAL(enter_prom) #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE -_GLOBAL(mcount) + +#define TOCSAVE 24 + _GLOBAL(_mcount) - blr + nop // REQUIRED for ftrace, to calculate local/global entry diff +.localentry _mcount,.-_mcount + mflr r0 + mtctr r0 + + LOAD_REG_ADDR_PIC(r12,ftrace_trace_function) + ld r12,0(r12) + LOAD_REG_ADDR_PIC(r0,ftrace_stub) + cmpd r0,r12 + ld r0,LRSAVE(r1) + bne- 2f + + mtlr r0 + bctr + +2: /* here we have (*ftrace_trace_function)() in r12, + "selfpc" in CTR + and "frompc" in r0 */ + + mtlr r0 + bctr + +_GLOBAL(ftrace_caller) + mr r0,r2 // global (module) call: save module TOC + b 1f +.localentry ftrace_caller,.-ftrace_caller + mr r0,r2 // local call: callee's TOC == our TOC + b 2f + +1: addis r2,r12,(.TOC.-0b)@ha + addi r2,r2,(.TOC.-0b)@l + +2: // Here we have our proper TOC ptr in R2, + // and the one we need to restore on return in r0. + + ld r12, 16(r1) // get caller's adress + + stdu r1,-SWITCH_FRAME_SIZE(r1) + + std r12, _LINK(r1) + SAVE_8GPRS(0,r1) + std r0,TOCSAVE(r1) + SAVE_8GPRS(8,r1) + SAVE_8GPRS(16,r1) + SAVE_8GPRS(24,r1) + + + LOAD_REG_IMMEDIATE(r3,function_trace_op) + ld r5,0(r3) + + mflr r3 + std r3, _NIP(r1) + std r3, 16(r1) + subi r3, r3, MCOUNT_INSN_SIZE + mfmsr r4 + std r4, _MSR(r1) + mfctr r4 + std r4, _CTR(r1) + mfxer r4 + std r4, _XER(r1) + mr r4, r12 + addi r6, r1 ,STACK_FRAME_OVERHEAD -_GLOBAL_TOC(ftrace_caller) - /* Taken from output of objdump from lib64/glibc */ - mflr r3 - ld r11, 0(r1) - stdu r1, -112(r1) - std r3, 128(r1) - ld r4, 16(r11) - subi r3, r3, MCOUNT_INSN_SIZE .globl ftrace_call ftrace_call: bl ftrace_stub nop + + ld r3, _NIP(r1) + mtlr r3 + + REST_8GPRS(0,r1) + REST_8GPRS(8,r1) + REST_8GPRS(16,r1) + REST_8GPRS(24,r1) + + addi r1, r1, SWITCH_FRAME_SIZE + + ld r12, 16(r1) // get caller's adress + mr r2,r0 // restore callee's TOC + mflr r0 // move this LR to CTR + mtctr r0 + mr r0,r12 // restore callee's lr at _mcount site + mtlr r0 + bctr // jump after _mcount site + #ifdef CONFIG_FUNCTION_GRAPH_TRACER .globl ftrace_graph_call ftrace_graph_call: b ftrace_graph_stub _GLOBAL(ftrace_graph_stub) #endif - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 + _GLOBAL(ftrace_stub) + nop + nop +.localentry ftrace_stub,.-ftrace_stub blr #else _GLOBAL_TOC(_mcount) @@ -1211,12 +1286,12 @@ _GLOBAL(ftrace_stub) #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(ftrace_graph_caller) /* load r4 with local address */ - ld r4, 128(r1) + ld r4, LRSAVE+SWITCH_FRAME_SIZE(r1) subi r4, r4, MCOUNT_INSN_SIZE /* Grab the LR out of the caller stack frame */ - ld r11, 112(r1) - ld r3, 16(r11) + ld r11, SWITCH_FRAME_SIZE(r1) + ld r3, LRSAVE(r11) bl prepare_ftrace_return nop @@ -1228,10 +1303,7 @@ _GLOBAL(ftrace_graph_caller) ld r11, 112(r1) std r3, 16(r11) - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 - blr + b ftrace_graph_stub _GLOBAL(return_to_handler) /* need to save return values */ diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 44d4d8e..349d07c 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -61,8 +61,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) return -EFAULT; /* Make sure it is what we expect it to be */ - if (replaced != old) + if (replaced != old) { + printk(KERN_ERR "%p: replaced (%#x) != old (%#x)", + (void *)ip, replaced, old); return -EINVAL; + } /* replace the text with the new text */ if (patch_instruction((unsigned int *)ip, new)) @@ -106,14 +109,16 @@ static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int op; + unsigned int op, op0, op1, pop; unsigned long entry, ptr; unsigned long ip = rec->ip; void *tramp; /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) + if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { + printk(KERN_ERR "Fetching opcode failed.\n"); return -EFAULT; + } /* Make sure that that this is still a 24bit jump */ if (!is_bl_op(op)) { @@ -158,10 +163,42 @@ __ftrace_make_nop(struct module *mod, * * Use a b +8 to jump over the load. */ - op = 0x48000008; /* b +8 */ - if (patch_instruction((unsigned int *)ip, op)) + pop = 0x48000008; /* b +8 */ + + /* + * Check what is in the next instruction. We can see ld r2,40(r1), but + * on first pass after boot we will see mflr r0. + */ + if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op failed.\n"); + return -EFAULT; + } + + if (op != 0xe8410028) { /* ld r2,STACK_OFFSET(r1) */ + + if (probe_kernel_read(&op0, (void *)(ip-8), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op0 failed.\n"); + return -EFAULT; + } + + if (probe_kernel_read(&op1, (void *)(ip-4), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op1 failed.\n"); + return -EFAULT; + } + + if (op0 != 0x7c0802a6 && op1 != 0xf8010010) { /* mflr r0 ; std r0,LRSAVE(r1) */ + printk(KERN_ERR "Unexpected instructions around bl when enabling dynamic ftrace! (%08x,%08x,bl,%08x)\n", op0, op1, op); + return -EINVAL; + } + + pop = PPC_INST_NOP; /* When using -mkernel_profile there is no load to jump over */ + } + + if (patch_instruction((unsigned int *)ip, pop)) { + printk(KERN_ERR "Patching NOP failed.\n"); return -EPERM; + } return 0; } @@ -287,6 +324,13 @@ int ftrace_make_nop(struct module *mod, #ifdef CONFIG_MODULES #ifdef CONFIG_PPC64 +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr) +{ + return ftrace_make_call(rec, addr); +} +#endif static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { @@ -306,11 +350,18 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) * The load offset is different depending on the ABI. For simplicity * just mask it out when doing the compare. */ +#if 0 // -pg, no -mprofile-kernel if ((op[0] != 0x48000008) || ((op[1] & 0xffff0000) != 0xe8410000)) { - pr_err("Unexpected call sequence: %x %x\n", op[0], op[1]); + pr_err("Unexpected call sequence at %p: %x %x\n", ip, op[0], op[1]); return -EINVAL; } - +#else + /* look for patched "NOP" on ppc64 with -mprofile-kernel */ + if ((op[0] != 0x60000000) ) { + pr_err("Unexpected call at %p: %x\n", ip, op[0]); + return -EINVAL; + } +#endif /* If we never set up a trampoline to ftrace_caller, then bail */ if (!rec->arch.mod->arch.tramp) { pr_err("No ftrace trampoline\n"); @@ -330,7 +381,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return 0; } -#else +#else /* !CONFIG_PPC64: */ static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 6838451..1428ad8 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -138,12 +138,22 @@ static u32 ppc64_stub_insns[] = { 0x4e800420 /* bctr */ }; +/* In case of _mcount calls or dynamic ftracing, Do not save the + current callee's TOC (in R2) again into the original caller's stack + frame during this trampoline hop. The stack frame already holds + that of the original caller. _mcount and ftrace_caller will take + care of this TOC value themselves. +*/ +#define SQUASH_TOC_SAVE_INSN(trampoline_addr) \ + ((struct ppc64_stub_entry*)(trampoline_addr))-> \ + jump[2] = PPC_INST_NOP; + #ifdef CONFIG_DYNAMIC_FTRACE static u32 ppc64_stub_mask[] = { 0xffff0000, 0xffff0000, - 0xffffffff, + 0x00000000, 0xffffffff, #if !defined(_CALL_ELF) || _CALL_ELF != 2 0xffffffff, @@ -170,6 +180,9 @@ bool is_module_trampoline(u32 *p) if ((insna & mask) != (insnb & mask)) return false; } + if (insns[2] != ppc64_stub_insns[2] && + insns[2] != PPC_INST_NOP ) + return false; return true; } @@ -475,6 +488,14 @@ static unsigned long stub_for_addr(Elf64_Shdr *sechdrs, static int restore_r2(u32 *instruction, struct module *me) { if (*instruction != PPC_INST_NOP) { + + /* -mprofile_kernel sequence starting with mflr r0; std r0, LRSAVE(r1) */ + if (instruction[-3] == 0x7c0802a6 && instruction[-2] == 0xf8010010) { + /* Nothing to be done here, it's a _mcount call location + and r2 will have to be restored in the _mcount function */ + return 2; + }; + pr_err("%s: Expect noop after relocate, got %08x\n", me->name, *instruction); return 0; @@ -490,7 +511,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, unsigned int relsec, struct module *me) { - unsigned int i; + unsigned int i, r2; Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr; Elf64_Sym *sym; unsigned long *location; @@ -603,8 +624,11 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, value = stub_for_addr(sechdrs, value, me); if (!value) return -ENOENT; - if (!restore_r2((u32 *)location + 1, me)) + if (!(r2 = restore_r2((u32 *)location + 1, me))) return -ENOEXEC; + /* Squash the TOC saver for profiler calls */ + if (!strcmp("_mcount", strtab+sym->st_name)) + SQUASH_TOC_SAVE_INSN(value); } else value += local_entry_offset(sym); @@ -665,6 +689,9 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, me->arch.tramp = stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me); + /* ftrace_caller will take care of the TOC; + do not clobber original caller's value. */ + SQUASH_TOC_SAVE_INSN(me->arch.tramp); #endif return 0; ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH 2/4] ppc64 ftrace_with_regs configuration variables 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-11 9:58 ` [PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe @ 2015-06-11 9:59 ` Torsten Duwe 2015-06-11 10:01 ` [PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe ` (2 subsequent siblings) 4 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-11 9:59 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel * Makefile: - globally use -mprofile-kernel in case it's configured. * arch/powerpc/Kconfig / kernel/trace/Kconfig: - declare that ppc64 HAVE_MPROFILE_KERNEL and HAVE_DYNAMIC_FTRACE_WITH_REGS, and use it. Signed-off-by: Torsten Duwe <duwe@suse.de> -- Makefile | 5 ++++- arch/powerpc/Kconfig | 2 ++ kernel/trace/Kconfig | 5 +++++ 3 files changed, 11 insertions(+), 1 deletion(-) -- diff --git a/Makefile b/Makefile index 3d16bcc..bbd5e87 100644 --- a/Makefile +++ b/Makefile @@ -733,7 +733,10 @@ export CC_FLAGS_FTRACE ifdef CONFIG_HAVE_FENTRY CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY) endif -KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY) +ifdef CONFIG_HAVE_MPROFILE_KERNEL +CC_USING_MPROFILE_KERNEL := $(call cc-option, -mprofile-kernel -DCC_USING_MPROFILE_KERNEL) +endif +KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY) $(CC_USING_MPROFILE_KERNEL) KBUILD_AFLAGS += $(CC_USING_FENTRY) ifdef CONFIG_DYNAMIC_FTRACE ifdef CONFIG_HAVE_C_RECORDMCOUNT diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 22b0940..566f204 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -94,8 +94,10 @@ config PPC select OF_RESERVED_MEM select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER + select HAVE_MPROFILE_KERNEL select SYSCTL_EXCEPTION_TRACE select ARCH_WANT_OPTIONAL_GPIOLIB select VIRT_TO_BUS if !PPC64 diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a5da09c..dd53f3d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -52,6 +52,11 @@ config HAVE_FENTRY help Arch supports the gcc options -pg with -mfentry +config HAVE_MPROFILE_KERNEL + bool + help + Arch supports the gcc options -pg with -mprofile-kernel + config HAVE_C_RECORDMCOUNT bool help ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-11 9:58 ` [PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe 2015-06-11 9:59 ` [PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe @ 2015-06-11 10:01 ` Torsten Duwe 2015-06-11 10:03 ` [PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 4 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-11 10:01 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel Using -mprofile-kernel on early boot code not only confuses the checker but is also useless, as the infrastructure is not yet in place. Proceed like with -pg (remove it from CFLAGS), equally with time.o and ftrace itself. * arch/powerpc/kernel/Makefile: - remove -mprofile-kernel from low level and boot code objects' CFLAGS for FUNCTION_TRACER configurations. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/kernel/Makefile | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) -- diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 502cf69..fb33fc5 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -17,14 +17,14 @@ endif ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code -CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog -mprofile-kernel # do not trace tracer code -CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog -mprofile-kernel # timers used by tracing -CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog -mprofile-kernel endif obj-y := cputable.o ptrace.o syscalls.o \ ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH 4/4] ppc64 ftrace_with_regs recursion protection 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (2 preceding siblings ...) 2015-06-11 10:01 ` [PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe @ 2015-06-11 10:03 ` Torsten Duwe 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 4 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-11 10:03 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel This is an *emergency* parachute to avoid an endless recursion and consecutively a kernel stack overflow, should any function within some ftrace framework cause an access fault, which calls _mcount / ftrace_caller in return and so on. It might also call an ftrace'd function directly. As Michael Ellerman pointed out, it is a tedious and error-prone task to maintain a complete list of those functions that _might_ get called from *_access_fault or any dynamic tracer function. So we'll concentrate on the most frequent cases to enhance performance later, while for now sticking with this fill-in. It will later serve as a backup protection. * arch/powerpc/kernel/entry_64.S: - test-and-set TRACE_FTRACE_BIT in task_struct's trace_recursion, do not call the actual tracer function if set, clear flag on return. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/entry_64.S | 15 +++++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) -- diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 4717859..ae10752 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -72,6 +72,7 @@ int main(void) DEFINE(THREAD, offsetof(struct task_struct, thread)); DEFINE(MM, offsetof(struct task_struct, mm)); DEFINE(MMCONTEXTID, offsetof(struct mm_struct, context.id)); + DEFINE(TASK_TRACEREC, offsetof(struct task_struct, trace_recursion)); #ifdef CONFIG_PPC64 DEFINE(AUDITCONTEXT, offsetof(struct task_struct, audit_context)); DEFINE(SIGSEGV, SIGSEGV); diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index a4132ef..4768104 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1202,7 +1202,13 @@ _GLOBAL(ftrace_caller) SAVE_8GPRS(16,r1) SAVE_8GPRS(24,r1) - + ld r3, PACACURRENT(r13) + ld r4, TASK_TRACEREC(r3) + andi. r5, r4, 0x0010 // ( 1 << TRACE_FTRACE_BIT ) + ori r4, r4, 0x0010 + std r4, TASK_TRACEREC(r3) + bne- 3f // ftrace in progress - avoid recursion! + LOAD_REG_IMMEDIATE(r3,function_trace_op) ld r5,0(r3) @@ -1224,9 +1230,14 @@ ftrace_call: bl ftrace_stub nop + ld r3, PACACURRENT(r13) + ld r4, TASK_TRACEREC(r3) + andi. r4, r4, 0xffef // ~( 1 << TRACE_FTRACE_BIT ) + std r4, TASK_TRACEREC(r3) + ld r3, _NIP(r1) mtlr r3 - +3: REST_8GPRS(0,r1) REST_8GPRS(8,r1) REST_8GPRS(16,r1) ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (3 preceding siblings ...) 2015-06-11 10:03 ` [PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe @ 2015-06-18 16:17 ` Torsten Duwe 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe ` (6 more replies) 4 siblings, 7 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-18 16:17 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel Did I miss anything else? I have the notrace optimisations and kernel live patching in the queue, which depends on this, so I'd really appreciate a comment whether it is acceptable in this form or not. Thanks in advance! Torsten ^ permalink raw reply [flat|nested] 27+ messages in thread
* [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe @ 2015-06-18 16:21 ` Torsten Duwe 2015-06-18 16:49 ` Steven Rostedt 2015-06-19 13:26 ` Steven Rostedt 2015-06-18 16:22 ` [RESEND PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe ` (5 subsequent siblings) 6 siblings, 2 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-18 16:21 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel Implement FTRACE_WITH_REGS for powerpc64, on ELF ABI v2. Initial work started by Vojtech Pavlik, used with permission. * arch/powerpc/kernel/entry_64.S: - enhance _mcount with a stub to test (ftrace_trace_function == &ftrace_stub) as suggested in Documentation/trace/ftrace-design.txt (for reference only, patched out at runtime) - Implement an effective ftrace_caller that works from within the kernel binary as well as from modules. * arch/powerpc/kernel/ftrace.c: - be prepared to deal with ppc64 ELV ABI v2, especially calls to _mcount that result from gcc -mprofile-kernel * arch/powerpc/kernel/module_64.c: - do not save the TOC pointer on the trampoline when the destination is ftrace_caller. This trampoline jump happens from a function prologue before a new stack frame is set up, so bad things may happen otherwise... - relax is_module_trampoline() to recognise the modified trampoline. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/include/asm/ftrace.h | 5 + arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- arch/powerpc/kernel/module_64.c | 33 ++++++++++- 4 files changed, 186 insertions(+), 31 deletions(-) -- diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index e366187..6111191 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -46,6 +46,8 @@ extern void _mcount(void); #ifdef CONFIG_DYNAMIC_FTRACE +# define FTRACE_ADDR ((unsigned long)ftrace_caller+8) +# define FTRACE_REGS_ADDR FTRACE_ADDR static inline unsigned long ftrace_call_adjust(unsigned long addr) { /* reloction of mcount call site is the same as the address */ @@ -58,6 +60,9 @@ struct dyn_arch_ftrace { #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* __ASSEMBLY__ */ +#ifdef CONFIG_DYNAMIC_FTRACE +#define ARCH_SUPPORTS_FTRACE_OPS 1 +#endif #endif #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) && !defined(__ASSEMBLY__) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index d180caf..a4132ef 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1152,32 +1152,107 @@ _GLOBAL(enter_prom) #ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE -_GLOBAL(mcount) + +#define TOCSAVE 24 + _GLOBAL(_mcount) - blr + nop // REQUIRED for ftrace, to calculate local/global entry diff +.localentry _mcount,.-_mcount + mflr r0 + mtctr r0 + + LOAD_REG_ADDR_PIC(r12,ftrace_trace_function) + ld r12,0(r12) + LOAD_REG_ADDR_PIC(r0,ftrace_stub) + cmpd r0,r12 + ld r0,LRSAVE(r1) + bne- 2f + + mtlr r0 + bctr + +2: /* here we have (*ftrace_trace_function)() in r12, + "selfpc" in CTR + and "frompc" in r0 */ + + mtlr r0 + bctr + +_GLOBAL(ftrace_caller) + mr r0,r2 // global (module) call: save module TOC + b 1f +.localentry ftrace_caller,.-ftrace_caller + mr r0,r2 // local call: callee's TOC == our TOC + b 2f + +1: addis r2,r12,(.TOC.-0b)@ha + addi r2,r2,(.TOC.-0b)@l + +2: // Here we have our proper TOC ptr in R2, + // and the one we need to restore on return in r0. + + ld r12, 16(r1) // get caller's adress + + stdu r1,-SWITCH_FRAME_SIZE(r1) + + std r12, _LINK(r1) + SAVE_8GPRS(0,r1) + std r0,TOCSAVE(r1) + SAVE_8GPRS(8,r1) + SAVE_8GPRS(16,r1) + SAVE_8GPRS(24,r1) + + + LOAD_REG_IMMEDIATE(r3,function_trace_op) + ld r5,0(r3) + + mflr r3 + std r3, _NIP(r1) + std r3, 16(r1) + subi r3, r3, MCOUNT_INSN_SIZE + mfmsr r4 + std r4, _MSR(r1) + mfctr r4 + std r4, _CTR(r1) + mfxer r4 + std r4, _XER(r1) + mr r4, r12 + addi r6, r1 ,STACK_FRAME_OVERHEAD -_GLOBAL_TOC(ftrace_caller) - /* Taken from output of objdump from lib64/glibc */ - mflr r3 - ld r11, 0(r1) - stdu r1, -112(r1) - std r3, 128(r1) - ld r4, 16(r11) - subi r3, r3, MCOUNT_INSN_SIZE .globl ftrace_call ftrace_call: bl ftrace_stub nop + + ld r3, _NIP(r1) + mtlr r3 + + REST_8GPRS(0,r1) + REST_8GPRS(8,r1) + REST_8GPRS(16,r1) + REST_8GPRS(24,r1) + + addi r1, r1, SWITCH_FRAME_SIZE + + ld r12, 16(r1) // get caller's adress + mr r2,r0 // restore callee's TOC + mflr r0 // move this LR to CTR + mtctr r0 + mr r0,r12 // restore callee's lr at _mcount site + mtlr r0 + bctr // jump after _mcount site + #ifdef CONFIG_FUNCTION_GRAPH_TRACER .globl ftrace_graph_call ftrace_graph_call: b ftrace_graph_stub _GLOBAL(ftrace_graph_stub) #endif - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 + _GLOBAL(ftrace_stub) + nop + nop +.localentry ftrace_stub,.-ftrace_stub blr #else _GLOBAL_TOC(_mcount) @@ -1211,12 +1286,12 @@ _GLOBAL(ftrace_stub) #ifdef CONFIG_FUNCTION_GRAPH_TRACER _GLOBAL(ftrace_graph_caller) /* load r4 with local address */ - ld r4, 128(r1) + ld r4, LRSAVE+SWITCH_FRAME_SIZE(r1) subi r4, r4, MCOUNT_INSN_SIZE /* Grab the LR out of the caller stack frame */ - ld r11, 112(r1) - ld r3, 16(r11) + ld r11, SWITCH_FRAME_SIZE(r1) + ld r3, LRSAVE(r11) bl prepare_ftrace_return nop @@ -1228,10 +1303,7 @@ _GLOBAL(ftrace_graph_caller) ld r11, 112(r1) std r3, 16(r11) - ld r0, 128(r1) - mtlr r0 - addi r1, r1, 112 - blr + b ftrace_graph_stub _GLOBAL(return_to_handler) /* need to save return values */ diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 44d4d8e..349d07c 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -61,8 +61,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) return -EFAULT; /* Make sure it is what we expect it to be */ - if (replaced != old) + if (replaced != old) { + printk(KERN_ERR "%p: replaced (%#x) != old (%#x)", + (void *)ip, replaced, old); return -EINVAL; + } /* replace the text with the new text */ if (patch_instruction((unsigned int *)ip, new)) @@ -106,14 +109,16 @@ static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int op; + unsigned int op, op0, op1, pop; unsigned long entry, ptr; unsigned long ip = rec->ip; void *tramp; /* read where this goes */ - if (probe_kernel_read(&op, (void *)ip, sizeof(int))) + if (probe_kernel_read(&op, (void *)ip, sizeof(int))) { + printk(KERN_ERR "Fetching opcode failed.\n"); return -EFAULT; + } /* Make sure that that this is still a 24bit jump */ if (!is_bl_op(op)) { @@ -158,10 +163,42 @@ __ftrace_make_nop(struct module *mod, * * Use a b +8 to jump over the load. */ - op = 0x48000008; /* b +8 */ - if (patch_instruction((unsigned int *)ip, op)) + pop = 0x48000008; /* b +8 */ + + /* + * Check what is in the next instruction. We can see ld r2,40(r1), but + * on first pass after boot we will see mflr r0. + */ + if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op failed.\n"); + return -EFAULT; + } + + if (op != 0xe8410028) { /* ld r2,STACK_OFFSET(r1) */ + + if (probe_kernel_read(&op0, (void *)(ip-8), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op0 failed.\n"); + return -EFAULT; + } + + if (probe_kernel_read(&op1, (void *)(ip-4), MCOUNT_INSN_SIZE)) { + printk(KERN_ERR "Fetching op1 failed.\n"); + return -EFAULT; + } + + if (op0 != 0x7c0802a6 && op1 != 0xf8010010) { /* mflr r0 ; std r0,LRSAVE(r1) */ + printk(KERN_ERR "Unexpected instructions around bl when enabling dynamic ftrace! (%08x,%08x,bl,%08x)\n", op0, op1, op); + return -EINVAL; + } + + pop = PPC_INST_NOP; /* When using -mkernel_profile there is no load to jump over */ + } + + if (patch_instruction((unsigned int *)ip, pop)) { + printk(KERN_ERR "Patching NOP failed.\n"); return -EPERM; + } return 0; } @@ -287,6 +324,13 @@ int ftrace_make_nop(struct module *mod, #ifdef CONFIG_MODULES #ifdef CONFIG_PPC64 +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, + unsigned long addr) +{ + return ftrace_make_call(rec, addr); +} +#endif static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { @@ -306,11 +350,18 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) * The load offset is different depending on the ABI. For simplicity * just mask it out when doing the compare. */ +#if 0 // -pg, no -mprofile-kernel if ((op[0] != 0x48000008) || ((op[1] & 0xffff0000) != 0xe8410000)) { - pr_err("Unexpected call sequence: %x %x\n", op[0], op[1]); + pr_err("Unexpected call sequence at %p: %x %x\n", ip, op[0], op[1]); return -EINVAL; } - +#else + /* look for patched "NOP" on ppc64 with -mprofile-kernel */ + if ((op[0] != 0x60000000) ) { + pr_err("Unexpected call at %p: %x\n", ip, op[0]); + return -EINVAL; + } +#endif /* If we never set up a trampoline to ftrace_caller, then bail */ if (!rec->arch.mod->arch.tramp) { pr_err("No ftrace trampoline\n"); @@ -330,7 +381,7 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) return 0; } -#else +#else /* !CONFIG_PPC64: */ static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 6838451..1428ad8 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -138,12 +138,22 @@ static u32 ppc64_stub_insns[] = { 0x4e800420 /* bctr */ }; +/* In case of _mcount calls or dynamic ftracing, Do not save the + current callee's TOC (in R2) again into the original caller's stack + frame during this trampoline hop. The stack frame already holds + that of the original caller. _mcount and ftrace_caller will take + care of this TOC value themselves. +*/ +#define SQUASH_TOC_SAVE_INSN(trampoline_addr) \ + ((struct ppc64_stub_entry*)(trampoline_addr))-> \ + jump[2] = PPC_INST_NOP; + #ifdef CONFIG_DYNAMIC_FTRACE static u32 ppc64_stub_mask[] = { 0xffff0000, 0xffff0000, - 0xffffffff, + 0x00000000, 0xffffffff, #if !defined(_CALL_ELF) || _CALL_ELF != 2 0xffffffff, @@ -170,6 +180,9 @@ bool is_module_trampoline(u32 *p) if ((insna & mask) != (insnb & mask)) return false; } + if (insns[2] != ppc64_stub_insns[2] && + insns[2] != PPC_INST_NOP ) + return false; return true; } @@ -475,6 +488,14 @@ static unsigned long stub_for_addr(Elf64_Shdr *sechdrs, static int restore_r2(u32 *instruction, struct module *me) { if (*instruction != PPC_INST_NOP) { + + /* -mprofile_kernel sequence starting with mflr r0; std r0, LRSAVE(r1) */ + if (instruction[-3] == 0x7c0802a6 && instruction[-2] == 0xf8010010) { + /* Nothing to be done here, it's a _mcount call location + and r2 will have to be restored in the _mcount function */ + return 2; + }; + pr_err("%s: Expect noop after relocate, got %08x\n", me->name, *instruction); return 0; @@ -490,7 +511,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, unsigned int relsec, struct module *me) { - unsigned int i; + unsigned int i, r2; Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr; Elf64_Sym *sym; unsigned long *location; @@ -603,8 +624,11 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, value = stub_for_addr(sechdrs, value, me); if (!value) return -ENOENT; - if (!restore_r2((u32 *)location + 1, me)) + if (!(r2 = restore_r2((u32 *)location + 1, me))) return -ENOEXEC; + /* Squash the TOC saver for profiler calls */ + if (!strcmp("_mcount", strtab+sym->st_name)) + SQUASH_TOC_SAVE_INSN(value); } else value += local_entry_offset(sym); @@ -665,6 +689,9 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, me->arch.tramp = stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me); + /* ftrace_caller will take care of the TOC; + do not clobber original caller's value. */ + SQUASH_TOC_SAVE_INSN(me->arch.tramp); #endif return 0; ^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe @ 2015-06-18 16:49 ` Steven Rostedt 2015-06-19 12:01 ` Torsten Duwe 2015-06-19 13:26 ` Steven Rostedt 1 sibling, 1 reply; 27+ messages in thread From: Steven Rostedt @ 2015-06-18 16:49 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, 18 Jun 2015 18:21:07 +0200 Torsten Duwe <duwe@lst.de> wrote: > + > _GLOBAL(ftrace_stub) > + nop > + nop > +.localentry ftrace_stub,.-ftrace_stub You might want to run checkpatch and fix your whitespace errors. -- Steve > blr > #else > _GLOBAL_TOC(_mcount) > @@ -1211,12 +1286,12 @@ _GLOBAL(ftrace_stub) ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation 2015-06-18 16:49 ` Steven Rostedt @ 2015-06-19 12:01 ` Torsten Duwe 0 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 12:01 UTC (permalink / raw) To: Steven Rostedt; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, Jun 18, 2015 at 12:49:00PM -0400, Steven Rostedt wrote: > On Thu, 18 Jun 2015 18:21:07 +0200 > Torsten Duwe <duwe@lst.de> wrote: > > > + > > _GLOBAL(ftrace_stub) > > + nop > > + nop > > +.localentry ftrace_stub,.-ftrace_stub > > You might want to run checkpatch and fix your whitespace errors. Right. Will do. Thanks, Torsten -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation @ 2015-06-19 12:01 ` Torsten Duwe 0 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 12:01 UTC (permalink / raw) To: Steven Rostedt; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, Jun 18, 2015 at 12:49:00PM -0400, Steven Rostedt wrote: > On Thu, 18 Jun 2015 18:21:07 +0200 > Torsten Duwe <duwe@lst.de> wrote: > > > + > > _GLOBAL(ftrace_stub) > > + nop > > + nop > > +.localentry ftrace_stub,.-ftrace_stub > > You might want to run checkpatch and fix your whitespace errors. Right. Will do. Thanks, Torsten ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe @ 2015-06-19 13:26 ` Steven Rostedt 2015-06-19 13:26 ` Steven Rostedt 1 sibling, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 13:26 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, 18 Jun 2015 18:21:07 +0200 Torsten Duwe <duwe@lst.de> wrote: > Implement FTRACE_WITH_REGS for powerpc64, on ELF ABI v2. > Initial work started by Vojtech Pavlik, used with permission. > > * arch/powerpc/kernel/entry_64.S: > - enhance _mcount with a stub to test (ftrace_trace_function == &ftrace_stub) > as suggested in Documentation/trace/ftrace-design.txt > (for reference only, patched out at runtime) > - Implement an effective ftrace_caller that works from within the kernel > binary as well as from modules. > * arch/powerpc/kernel/ftrace.c: > - be prepared to deal with ppc64 ELV ABI v2, especially calls to _mcount > that result from gcc -mprofile-kernel > * arch/powerpc/kernel/module_64.c: > - do not save the TOC pointer on the trampoline when the destination > is ftrace_caller. This trampoline jump happens from a function prologue > before a new stack frame is set up, so bad things may happen otherwise... > - relax is_module_trampoline() to recognise the modified trampoline. > > Signed-off-by: Torsten Duwe <duwe@suse.de> > -- FYI, the standard notation after the change log is '---' not '--'. That way git will chop off this from the change log. When I did a git am -s on this patch I had: Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/include/asm/ftrace.h | 5 + arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- arch/powerpc/kernel/module_64.c | 33 ++++++++++- 4 files changed, 186 insertions(+), 31 deletions(-) -- Signed-off-by: Steven Rostedt <rostedt@goodmis.org> -- Steve > arch/powerpc/include/asm/ftrace.h | 5 + > arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- > arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- > arch/powerpc/kernel/module_64.c | 33 ++++++++++- > 4 files changed, 186 insertions(+), 31 deletions(-) > -- > diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h > index e366187..6111191 100644 > --- a/arch/powerpc/include/asm/ftrace.h > +++ b/arch/powerpc/include/asm/ftrace.h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation @ 2015-06-19 13:26 ` Steven Rostedt 0 siblings, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 13:26 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, 18 Jun 2015 18:21:07 +0200 Torsten Duwe <duwe@lst.de> wrote: > Implement FTRACE_WITH_REGS for powerpc64, on ELF ABI v2. > Initial work started by Vojtech Pavlik, used with permission. > > * arch/powerpc/kernel/entry_64.S: > - enhance _mcount with a stub to test (ftrace_trace_function == &ftrace_stub) > as suggested in Documentation/trace/ftrace-design.txt > (for reference only, patched out at runtime) > - Implement an effective ftrace_caller that works from within the kernel > binary as well as from modules. > * arch/powerpc/kernel/ftrace.c: > - be prepared to deal with ppc64 ELV ABI v2, especially calls to _mcount > that result from gcc -mprofile-kernel > * arch/powerpc/kernel/module_64.c: > - do not save the TOC pointer on the trampoline when the destination > is ftrace_caller. This trampoline jump happens from a function prologue > before a new stack frame is set up, so bad things may happen otherwise... > - relax is_module_trampoline() to recognise the modified trampoline. > > Signed-off-by: Torsten Duwe <duwe@suse.de> > -- FYI, the standard notation after the change log is '---' not '--'. That way git will chop off this from the change log. When I did a git am -s on this patch I had: Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/include/asm/ftrace.h | 5 + arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- arch/powerpc/kernel/module_64.c | 33 ++++++++++- 4 files changed, 186 insertions(+), 31 deletions(-) -- Signed-off-by: Steven Rostedt <rostedt@goodmis.org> -- Steve > arch/powerpc/include/asm/ftrace.h | 5 + > arch/powerpc/kernel/entry_64.S | 112 +++++++++++++++++++++++++++++++------- > arch/powerpc/kernel/ftrace.c | 67 ++++++++++++++++++++-- > arch/powerpc/kernel/module_64.c | 33 ++++++++++- > 4 files changed, 186 insertions(+), 31 deletions(-) > -- > diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h > index e366187..6111191 100644 > --- a/arch/powerpc/include/asm/ftrace.h > +++ b/arch/powerpc/include/asm/ftrace.h ^ permalink raw reply [flat|nested] 27+ messages in thread
* [RESEND PATCH 2/4] ppc64 ftrace_with_regs configuration variables 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe @ 2015-06-18 16:22 ` Torsten Duwe 2015-06-18 16:24 ` [RESEND PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe ` (4 subsequent siblings) 6 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-18 16:22 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel * Makefile: - globally use -mprofile-kernel in case it's configured. * arch/powerpc/Kconfig / kernel/trace/Kconfig: - declare that ppc64 HAVE_MPROFILE_KERNEL and HAVE_DYNAMIC_FTRACE_WITH_REGS, and use it. Signed-off-by: Torsten Duwe <duwe@suse.de> -- Makefile | 5 ++++- arch/powerpc/Kconfig | 2 ++ kernel/trace/Kconfig | 5 +++++ 3 files changed, 11 insertions(+), 1 deletion(-) -- diff --git a/Makefile b/Makefile index 3d16bcc..bbd5e87 100644 --- a/Makefile +++ b/Makefile @@ -733,7 +733,10 @@ export CC_FLAGS_FTRACE ifdef CONFIG_HAVE_FENTRY CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY) endif -KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY) +ifdef CONFIG_HAVE_MPROFILE_KERNEL +CC_USING_MPROFILE_KERNEL := $(call cc-option, -mprofile-kernel -DCC_USING_MPROFILE_KERNEL) +endif +KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY) $(CC_USING_MPROFILE_KERNEL) KBUILD_AFLAGS += $(CC_USING_FENTRY) ifdef CONFIG_DYNAMIC_FTRACE ifdef CONFIG_HAVE_C_RECORDMCOUNT diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 22b0940..566f204 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -94,8 +94,10 @@ config PPC select OF_RESERVED_MEM select HAVE_FTRACE_MCOUNT_RECORD select HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER + select HAVE_MPROFILE_KERNEL select SYSCTL_EXCEPTION_TRACE select ARCH_WANT_OPTIONAL_GPIOLIB select VIRT_TO_BUS if !PPC64 diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index a5da09c..dd53f3d 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -52,6 +52,11 @@ config HAVE_FENTRY help Arch supports the gcc options -pg with -mfentry +config HAVE_MPROFILE_KERNEL + bool + help + Arch supports the gcc options -pg with -mprofile-kernel + config HAVE_C_RECORDMCOUNT bool help ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [RESEND PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe 2015-06-18 16:22 ` [RESEND PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe @ 2015-06-18 16:24 ` Torsten Duwe 2015-06-18 16:25 ` [RESEND PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe ` (3 subsequent siblings) 6 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-18 16:24 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel Using -mprofile-kernel on early boot code not only confuses the checker but is also useless, as the infrastructure is not yet in place. Proceed like with -pg (remove it from CFLAGS), equally with time.o and ftrace itself. * arch/powerpc/kernel/Makefile: - remove -mprofile-kernel from low level and boot code objects' CFLAGS for FUNCTION_TRACER configurations. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/kernel/Makefile | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) -- diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 502cf69..fb33fc5 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -17,14 +17,14 @@ endif ifdef CONFIG_FUNCTION_TRACER # Do not trace early boot code -CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog -CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog -mprofile-kernel +CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog -mprofile-kernel # do not trace tracer code -CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog -mprofile-kernel # timers used by tracing -CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog +CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog -mprofile-kernel endif obj-y := cputable.o ptrace.o syscalls.o \ ^ permalink raw reply related [flat|nested] 27+ messages in thread
* [RESEND PATCH 4/4] ppc64 ftrace_with_regs recursion protection 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (2 preceding siblings ...) 2015-06-18 16:24 ` [RESEND PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe @ 2015-06-18 16:25 ` Torsten Duwe 2015-06-18 16:55 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Steven Rostedt ` (2 subsequent siblings) 6 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-18 16:25 UTC (permalink / raw) To: Steven Rostedt, Michael Ellerman; +Cc: Jiri Kosina, linuxppc-dev, linux-kernel This is an *emergency* parachute to avoid an endless recursion and consecutively a kernel stack overflow, should any function within some ftrace framework cause an access fault, which calls _mcount / ftrace_caller in return and so on. It might also call an ftrace'd function directly. As Michael Ellerman pointed out, it is a tedious and error-prone task to maintain a complete list of those functions that _might_ get called from *_access_fault or any dynamic tracer function. So we'll concentrate on the most frequent cases to enhance performance later, while for now sticking with this fill-in. It will later serve as a backup protection. * arch/powerpc/kernel/entry_64.S: - test-and-set TRACE_FTRACE_BIT in task_struct's trace_recursion, do not call the actual tracer function if set, clear flag on return. Signed-off-by: Torsten Duwe <duwe@suse.de> -- arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/entry_64.S | 15 +++++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) -- diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 4717859..ae10752 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -72,6 +72,7 @@ int main(void) DEFINE(THREAD, offsetof(struct task_struct, thread)); DEFINE(MM, offsetof(struct task_struct, mm)); DEFINE(MMCONTEXTID, offsetof(struct mm_struct, context.id)); + DEFINE(TASK_TRACEREC, offsetof(struct task_struct, trace_recursion)); #ifdef CONFIG_PPC64 DEFINE(AUDITCONTEXT, offsetof(struct task_struct, audit_context)); DEFINE(SIGSEGV, SIGSEGV); diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index a4132ef..4768104 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1202,7 +1202,13 @@ _GLOBAL(ftrace_caller) SAVE_8GPRS(16,r1) SAVE_8GPRS(24,r1) - + ld r3, PACACURRENT(r13) + ld r4, TASK_TRACEREC(r3) + andi. r5, r4, 0x0010 // ( 1 << TRACE_FTRACE_BIT ) + ori r4, r4, 0x0010 + std r4, TASK_TRACEREC(r3) + bne- 3f // ftrace in progress - avoid recursion! + LOAD_REG_IMMEDIATE(r3,function_trace_op) ld r5,0(r3) @@ -1224,9 +1230,14 @@ ftrace_call: bl ftrace_stub nop + ld r3, PACACURRENT(r13) + ld r4, TASK_TRACEREC(r3) + andi. r4, r4, 0xffef // ~( 1 << TRACE_FTRACE_BIT ) + std r4, TASK_TRACEREC(r3) + ld r3, _NIP(r1) mtlr r3 - +3: REST_8GPRS(0,r1) REST_8GPRS(8,r1) REST_8GPRS(16,r1) ^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (3 preceding siblings ...) 2015-06-18 16:25 ` [RESEND PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe @ 2015-06-18 16:55 ` Steven Rostedt 2015-06-19 12:00 ` Torsten Duwe 2015-06-19 2:49 ` Michael Ellerman 2015-06-19 7:15 ` Denis Kirjanov 6 siblings, 1 reply; 27+ messages in thread From: Steven Rostedt @ 2015-06-18 16:55 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel [-- Attachment #1: Type: text/plain, Size: 1057 bytes --] On Thu, 18 Jun 2015 18:17:27 +0200 Torsten Duwe <duwe@lst.de> wrote: > Did I miss anything else? I have the notrace optimisations and > kernel live patching in the queue, which depends on this, so I'd > really appreciate a comment whether it is acceptable in this form > or not. Thanks in advance! > > Torsten I applied these patches against v4.1-rc8 and I get this compiling it for my electra: /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S: Assembler messages: /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1165: Error: unknown pseudo-op: `.localentry' /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1189: Error: unknown pseudo-op: `.localentry' /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1271: Error: unknown pseudo-op: `.localentry' /work/autotest/nobackup/powerpc-test.git/scripts/Makefile.build:294: recipe for target 'arch/powerpc/kernel/entry_64.o' failed make[2]: *** [arch/powerpc/kernel/entry_64.o] Error 1 Config attached. -- Steve [-- Attachment #2: config.gz --] [-- Type: application/gzip, Size: 17231 bytes --] ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-18 16:55 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Steven Rostedt @ 2015-06-19 12:00 ` Torsten Duwe 2015-06-19 12:40 ` Steven Rostedt 0 siblings, 1 reply; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 12:00 UTC (permalink / raw) To: Steven Rostedt; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel [-- Attachment #1: Type: text/plain, Size: 1293 bytes --] On Thu, Jun 18, 2015 at 12:55:39PM -0400, Steven Rostedt wrote: > > I applied these patches against v4.1-rc8 and I get this compiling it > for my electra: > > /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S: Assembler messages: > /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1165: Error: unknown pseudo-op: `.localentry' > /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1189: Error: unknown pseudo-op: `.localentry' > /work/autotest/nobackup/powerpc-test.git/arch/powerpc/kernel/entry_64.S:1271: Error: unknown pseudo-op: `.localentry' > /work/autotest/nobackup/powerpc-test.git/scripts/Makefile.build:294: recipe for target 'arch/powerpc/kernel/entry_64.o' failed > make[2]: *** [arch/powerpc/kernel/entry_64.o] Error 1 After removing your cross compile prefix, with your config I get: | kernel/bounds.c:1:0: error: -mcall-aixdesc incompatible with -mabi=elfv2 Are you building ppc64, little endian, ELF ABIv2 ? Is your cross compiler working properly? I'm compiling natively on that platform (faster for me than an x86 ;-) | GNU assembler (GNU Binutils; SUSE Linux Enterprise 12) 2.24.0.20140403-7 | gcc (SUSE Linux) 4.8.3 20140627 [gcc-4_8-branch revision 212064] 4.1.0-rc8 config attached. HTH, Torsten [-- Attachment #2: 41rc8-config.gz --] [-- Type: application/x-gzip, Size: 34204 bytes --] ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-19 12:00 ` Torsten Duwe @ 2015-06-19 12:40 ` Steven Rostedt 0 siblings, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 12:40 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, 19 Jun 2015 14:00:44 +0200 Torsten Duwe <duwe@lst.de> wrote: > | kernel/bounds.c:1:0: error: -mcall-aixdesc incompatible with -mabi=elfv2 > > Are you building ppc64, little endian, ELF ABIv2 ? It's big endian. > Is your cross compiler working properly? Well, just before applying your patches, I built and booted 4.1-rc8 on that box. Then I applied the patches and got the error on build. I just reverted your patches, and it builds again. > > I'm compiling natively on that platform (faster for me than an x86 ;-) x86 is bit faster for me to compile. > | GNU assembler (GNU Binutils; SUSE Linux Enterprise 12) 2.24.0.20140403-7 > | gcc (SUSE Linux) 4.8.3 20140627 [gcc-4_8-branch revision 212064] I'm using the cross tool chains from kernel.org https://www.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/ powerpc64-linux-gcc (GCC) 4.6.3 > > 4.1.0-rc8 config attached. Um, what do you want me to do with your config? If your patches don't build on my box when vanilla does, it's a regression. In other words, you broke my machine. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation @ 2015-06-19 12:40 ` Steven Rostedt 0 siblings, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 12:40 UTC (permalink / raw) To: Torsten Duwe; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, 19 Jun 2015 14:00:44 +0200 Torsten Duwe <duwe@lst.de> wrote: > | kernel/bounds.c:1:0: error: -mcall-aixdesc incompatible with -mabi=elfv2 > > Are you building ppc64, little endian, ELF ABIv2 ? It's big endian. > Is your cross compiler working properly? Well, just before applying your patches, I built and booted 4.1-rc8 on that box. Then I applied the patches and got the error on build. I just reverted your patches, and it builds again. > > I'm compiling natively on that platform (faster for me than an x86 ;-) x86 is bit faster for me to compile. > | GNU assembler (GNU Binutils; SUSE Linux Enterprise 12) 2.24.0.20140403-7 > | gcc (SUSE Linux) 4.8.3 20140627 [gcc-4_8-branch revision 212064] I'm using the cross tool chains from kernel.org https://www.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/ powerpc64-linux-gcc (GCC) 4.6.3 > > 4.1.0-rc8 config attached. Um, what do you want me to do with your config? If your patches don't build on my box when vanilla does, it's a regression. In other words, you broke my machine. -- Steve ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-19 12:40 ` Steven Rostedt @ 2015-06-19 13:18 ` Torsten Duwe -1 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 13:18 UTC (permalink / raw) To: Steven Rostedt; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, Jun 19, 2015 at 08:40:44AM -0400, Steven Rostedt wrote: > On Fri, 19 Jun 2015 14:00:44 +0200 > Torsten Duwe <duwe@lst.de> wrote: > > > > | kernel/bounds.c:1:0: error: -mcall-aixdesc incompatible with -mabi=elfv2 > > > > Are you building ppc64, little endian, ELF ABIv2 ? > > It's big endian. And ABIv1, consequently, and then you probably don't have .localentry. The code inherently assumes ABIv2, v1 does not work. I'll add a dependency on v2 then, if possible. Torsten -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation @ 2015-06-19 13:18 ` Torsten Duwe 0 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 13:18 UTC (permalink / raw) To: Steven Rostedt; +Cc: Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, Jun 19, 2015 at 08:40:44AM -0400, Steven Rostedt wrote: > On Fri, 19 Jun 2015 14:00:44 +0200 > Torsten Duwe <duwe@lst.de> wrote: > > > > | kernel/bounds.c:1:0: error: -mcall-aixdesc incompatible with -mabi=elfv2 > > > > Are you building ppc64, little endian, ELF ABIv2 ? > > It's big endian. And ABIv1, consequently, and then you probably don't have .localentry. The code inherently assumes ABIv2, v1 does not work. I'll add a dependency on v2 then, if possible. Torsten ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (4 preceding siblings ...) 2015-06-18 16:55 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Steven Rostedt @ 2015-06-19 2:49 ` Michael Ellerman 2015-06-19 7:15 ` Denis Kirjanov 6 siblings, 0 replies; 27+ messages in thread From: Michael Ellerman @ 2015-06-19 2:49 UTC (permalink / raw) To: Torsten Duwe; +Cc: Steven Rostedt, Jiri Kosina, linuxppc-dev, linux-kernel On Thu, 2015-06-18 at 18:17 +0200, Torsten Duwe wrote: > Did I miss anything else? I have the notrace optimisations and > kernel live patching in the queue, which depends on this, so I'd > really appreciate a comment whether it is acceptable in this form > or not. Thanks in advance! Hi Torsten, Sorry I just haven't had time to look at it this week while I've been doing linux-next. I'll try and review it next week. There's no need to resend, we keep track of things in patchwork: http://patchwork.ozlabs.org/project/linuxppc-dev/list/?submitter=2722 cheers ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe ` (5 preceding siblings ...) 2015-06-19 2:49 ` Michael Ellerman @ 2015-06-19 7:15 ` Denis Kirjanov 2015-06-19 12:17 ` Torsten Duwe 6 siblings, 1 reply; 27+ messages in thread From: Denis Kirjanov @ 2015-06-19 7:15 UTC (permalink / raw) To: Torsten Duwe Cc: Steven Rostedt, Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On 6/18/15, Torsten Duwe <duwe@lst.de> wrote: > Did I miss anything else? I have the notrace optimisations and > kernel live patching in the queue, which depends on this, so I'd > really appreciate a comment whether it is acceptable in this form > or not. Thanks in advance! Hi Torsten, could you provide a description how you did test that. Thanks. > > Torsten > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-19 7:15 ` Denis Kirjanov @ 2015-06-19 12:17 ` Torsten Duwe 0 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 12:17 UTC (permalink / raw) To: Denis Kirjanov Cc: Steven Rostedt, Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, Jun 19, 2015 at 10:15:44AM +0300, Denis Kirjanov wrote: > > Hi Torsten, > > could you provide a description how you did test that. Vanilla kernel, those patches on top, built as described to Steven in the previous mail (.config attached there, built natively on ppc64le ABIv2, mentioned tool versions) make vmlinux, make modules, build initrd qemu-system-ppc64 -no-reboot -enable-kvm -m 20480 -kernel vmlinux -initrd initrd.gz -append console=hvc0 -nographic -vga none inside: cd /sys/kernel/debug/tracing mkdir instances/Foo cd instances/Foo echo function > current_tracer current_tracer holds "nop" or "function"; the transition is accompanied by heavy binary patching. When the function tracer is active, almost all calls go through ftrace_caller. This should be enough for a start; the proper stack frame layout details for the tracer functions still remain to be checked... Torsten -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation @ 2015-06-19 12:17 ` Torsten Duwe 0 siblings, 0 replies; 27+ messages in thread From: Torsten Duwe @ 2015-06-19 12:17 UTC (permalink / raw) To: Denis Kirjanov Cc: Steven Rostedt, Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, Jun 19, 2015 at 10:15:44AM +0300, Denis Kirjanov wrote: > > Hi Torsten, > > could you provide a description how you did test that. Vanilla kernel, those patches on top, built as described to Steven in the previous mail (.config attached there, built natively on ppc64le ABIv2, mentioned tool versions) make vmlinux, make modules, build initrd qemu-system-ppc64 -no-reboot -enable-kvm -m 20480 -kernel vmlinux -initrd initrd.gz -append console=hvc0 -nographic -vga none inside: cd /sys/kernel/debug/tracing mkdir instances/Foo cd instances/Foo echo function > current_tracer current_tracer holds "nop" or "function"; the transition is accompanied by heavy binary patching. When the function tracer is active, almost all calls go through ftrace_caller. This should be enough for a start; the proper stack frame layout details for the tracer functions still remain to be checked... Torsten ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation 2015-06-19 12:17 ` Torsten Duwe @ 2015-06-19 12:41 ` Steven Rostedt -1 siblings, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 12:41 UTC (permalink / raw) To: Torsten Duwe Cc: Denis Kirjanov, Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, 19 Jun 2015 14:17:03 +0200 Torsten Duwe <duwe@lst.de> wrote: > On Fri, Jun 19, 2015 at 10:15:44AM +0300, Denis Kirjanov wrote: > > > > Hi Torsten, > > > > could you provide a description how you did test that. > > Vanilla kernel, those patches on top, built as described to > Steven in the previous mail (.config attached there, built > natively on ppc64le ABIv2, mentioned tool versions) > Great that you got it working on your machine. But you need to do it in a way that you don't break builds of existing machines, with existing (still supported) compilers. -- Steve > make vmlinux, make modules, build initrd > qemu-system-ppc64 -no-reboot -enable-kvm -m 20480 -kernel vmlinux > -initrd initrd.gz -append console=hvc0 -nographic -vga none > inside: > cd /sys/kernel/debug/tracing > mkdir instances/Foo > cd instances/Foo > echo function > current_tracer > > current_tracer holds "nop" or "function"; the transition is accompanied > by heavy binary patching. When the function tracer is active, almost all > calls go through ftrace_caller. This should be enough for a start; the > proper stack frame layout details for the tracer functions still remain > to be checked... > > Torsten -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/ ^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation @ 2015-06-19 12:41 ` Steven Rostedt 0 siblings, 0 replies; 27+ messages in thread From: Steven Rostedt @ 2015-06-19 12:41 UTC (permalink / raw) To: Torsten Duwe Cc: Denis Kirjanov, Michael Ellerman, Jiri Kosina, linuxppc-dev, linux-kernel On Fri, 19 Jun 2015 14:17:03 +0200 Torsten Duwe <duwe@lst.de> wrote: > On Fri, Jun 19, 2015 at 10:15:44AM +0300, Denis Kirjanov wrote: > > > > Hi Torsten, > > > > could you provide a description how you did test that. > > Vanilla kernel, those patches on top, built as described to > Steven in the previous mail (.config attached there, built > natively on ppc64le ABIv2, mentioned tool versions) > Great that you got it working on your machine. But you need to do it in a way that you don't break builds of existing machines, with existing (still supported) compilers. -- Steve > make vmlinux, make modules, build initrd > qemu-system-ppc64 -no-reboot -enable-kvm -m 20480 -kernel vmlinux > -initrd initrd.gz -append console=hvc0 -nographic -vga none > inside: > cd /sys/kernel/debug/tracing > mkdir instances/Foo > cd instances/Foo > echo function > current_tracer > > current_tracer holds "nop" or "function"; the transition is accompanied > by heavy binary patching. When the function tracer is active, almost all > calls go through ftrace_caller. This should be enough for a start; the > proper stack frame layout details for the tracer functions still remain > to be checked... > > Torsten ^ permalink raw reply [flat|nested] 27+ messages in thread
end of thread, other threads:[~2015-06-19 13:25 UTC | newest] Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-06-11 9:53 [PATCH 0/4] resend: ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-11 9:58 ` [PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe 2015-06-11 9:59 ` [PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe 2015-06-11 10:01 ` [PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe 2015-06-11 10:03 ` [PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe 2015-06-18 16:17 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Torsten Duwe 2015-06-18 16:21 ` [RESEND PATCH 1/4] ppc64 FTRACE_WITH_REGS implementation Torsten Duwe 2015-06-18 16:49 ` Steven Rostedt 2015-06-19 12:01 ` Torsten Duwe 2015-06-19 12:01 ` Torsten Duwe 2015-06-19 13:26 ` Steven Rostedt 2015-06-19 13:26 ` Steven Rostedt 2015-06-18 16:22 ` [RESEND PATCH 2/4] ppc64 ftrace_with_regs configuration variables Torsten Duwe 2015-06-18 16:24 ` [RESEND PATCH 3/4] ppc64 ftrace_with_regs: spare early boot and low level code Torsten Duwe 2015-06-18 16:25 ` [RESEND PATCH 4/4] ppc64 ftrace_with_regs recursion protection Torsten Duwe 2015-06-18 16:55 ` [RESEND PATCH 0/4] ppc64 LE ABI v2 ftrace-with-regs implementation Steven Rostedt 2015-06-19 12:00 ` Torsten Duwe 2015-06-19 12:40 ` Steven Rostedt 2015-06-19 12:40 ` Steven Rostedt 2015-06-19 13:18 ` Torsten Duwe 2015-06-19 13:18 ` Torsten Duwe 2015-06-19 2:49 ` Michael Ellerman 2015-06-19 7:15 ` Denis Kirjanov 2015-06-19 12:17 ` Torsten Duwe 2015-06-19 12:17 ` Torsten Duwe 2015-06-19 12:41 ` Steven Rostedt 2015-06-19 12:41 ` Steven Rostedt
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