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https://github.com/torvalds/linux.git
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Merge branch 'topic/mprofile-kernel' into next
Merge the ftrace changes to support -mprofile-kernel on ppc64le. This is a prerequisite for live patching, the support for which will be merged via the livepatch tree based on this topic branch.
This commit is contained in:
Michael Ellerman
commit
d8c0282f4d
@ -94,6 +94,7 @@ config PPC
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select OF_RESERVED_MEM
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select HAVE_FTRACE_MCOUNT_RECORD
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select HAVE_DYNAMIC_FTRACE
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select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL
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select HAVE_FUNCTION_TRACER
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select HAVE_FUNCTION_GRAPH_TRACER
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select SYSCTL_EXCEPTION_TRACE
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@ -373,6 +374,24 @@ config PPC_TRANSACTIONAL_MEM
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---help---
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Support user-mode Transactional Memory on POWERPC.
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config DISABLE_MPROFILE_KERNEL
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bool "Disable use of mprofile-kernel for kernel tracing"
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depends on PPC64 && CPU_LITTLE_ENDIAN
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default y
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help
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Selecting this options disables use of the mprofile-kernel ABI for
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kernel tracing. That will cause options such as live patching
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(CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to
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be disabled also.
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If you have a toolchain which supports mprofile-kernel, then you can
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enable this. Otherwise leave it disabled. If you're not sure, say
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"N".
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config MPROFILE_KERNEL
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depends on PPC64 && CPU_LITTLE_ENDIAN
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def_bool !DISABLE_MPROFILE_KERNEL
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config IOMMU_HELPER
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def_bool PPC64
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@ -133,6 +133,21 @@ else
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CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
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endif
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ifdef CONFIG_MPROFILE_KERNEL
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ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK)
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CC_FLAGS_FTRACE := -pg -mprofile-kernel
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KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL
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else
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# If the user asked for mprofile-kernel but the toolchain doesn't
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# support it, emit a warning and deliberately break the build later
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# with mprofile-kernel-not-supported. We would prefer to make this an
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# error right here, but then the user would never be able to run
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# oldconfig to change their configuration.
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$(warning Compiler does not support mprofile-kernel, set CONFIG_DISABLE_MPROFILE_KERNEL)
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CC_FLAGS_FTRACE := -mprofile-kernel-not-supported
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endif
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endif
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CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
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CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4)
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CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)
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@ -99,4 +99,25 @@ static inline unsigned long ppc_global_function_entry(void *func)
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#endif
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}
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#ifdef CONFIG_PPC64
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/*
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* Some instruction encodings commonly used in dynamic ftracing
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* and function live patching.
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*/
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/* This must match the definition of STK_GOT in <asm/ppc_asm.h> */
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#if defined(_CALL_ELF) && _CALL_ELF == 2
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#define R2_STACK_OFFSET 24
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#else
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#define R2_STACK_OFFSET 40
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#endif
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#define PPC_INST_LD_TOC (PPC_INST_LD | ___PPC_RT(__REG_R2) | \
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___PPC_RA(__REG_R1) | R2_STACK_OFFSET)
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/* usually preceded by a mflr r0 */
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#define PPC_INST_STD_LR (PPC_INST_STD | ___PPC_RS(__REG_R0) | \
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___PPC_RA(__REG_R1) | PPC_LR_STKOFF)
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#endif /* CONFIG_PPC64 */
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#endif /* _ASM_POWERPC_CODE_PATCHING_H */
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@ -46,6 +46,8 @@
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extern void _mcount(void);
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#ifdef CONFIG_DYNAMIC_FTRACE
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# define FTRACE_ADDR ((unsigned long)ftrace_caller)
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# define FTRACE_REGS_ADDR FTRACE_ADDR
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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/* reloction of mcount call site is the same as the address */
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@ -58,6 +60,9 @@ struct dyn_arch_ftrace {
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* __ASSEMBLY__ */
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#endif
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#endif
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#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64) && !defined(__ASSEMBLY__)
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@ -78,10 +78,18 @@ struct mod_arch_specific {
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# endif /* MODULE */
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#endif
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bool is_module_trampoline(u32 *insns);
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int module_trampoline_target(struct module *mod, u32 *trampoline,
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int module_trampoline_target(struct module *mod, unsigned long trampoline,
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unsigned long *target);
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#ifdef CONFIG_DYNAMIC_FTRACE
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int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs);
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#else
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static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
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{
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return 0;
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}
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#endif
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struct exception_table_entry;
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void sort_ex_table(struct exception_table_entry *start,
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struct exception_table_entry *finish);
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@ -22,6 +22,18 @@ static inline int in_kernel_text(unsigned long addr)
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return 0;
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}
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static inline unsigned long kernel_toc_addr(void)
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{
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/* Defined by the linker, see vmlinux.lds.S */
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extern unsigned long __toc_start;
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/*
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* The TOC register (r2) points 32kB into the TOC, so that 64kB of
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* the TOC can be addressed using a single machine instruction.
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*/
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return (unsigned long)(&__toc_start) + 0x8000UL;
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}
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static inline int overlaps_interrupt_vector_text(unsigned long start,
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unsigned long end)
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{
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@ -16,14 +16,14 @@ endif
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ifdef CONFIG_FUNCTION_TRACER
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# Do not trace early boot code
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CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_cputable.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_prom_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_btext.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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CFLAGS_REMOVE_prom.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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# do not trace tracer code
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CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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# timers used by tracing
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CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog
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CFLAGS_REMOVE_time.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
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endif
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obj-y := cputable.o ptrace.o syscalls.o \
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@ -1158,8 +1158,12 @@ _GLOBAL(enter_prom)
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#ifdef CONFIG_DYNAMIC_FTRACE
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_GLOBAL(mcount)
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_GLOBAL(_mcount)
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blr
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mflr r12
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mtctr r12
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mtlr r0
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bctr
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#ifndef CC_USING_MPROFILE_KERNEL
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_GLOBAL_TOC(ftrace_caller)
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/* Taken from output of objdump from lib64/glibc */
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mflr r3
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@ -1181,6 +1185,115 @@ _GLOBAL(ftrace_graph_stub)
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ld r0, 128(r1)
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mtlr r0
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addi r1, r1, 112
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#else /* CC_USING_MPROFILE_KERNEL */
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/*
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*
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* ftrace_caller() is the function that replaces _mcount() when ftrace is
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* active.
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*
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* We arrive here after a function A calls function B, and we are the trace
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* function for B. When we enter r1 points to A's stack frame, B has not yet
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* had a chance to allocate one yet.
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*
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* Additionally r2 may point either to the TOC for A, or B, depending on
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* whether B did a TOC setup sequence before calling us.
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*
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* On entry the LR points back to the _mcount() call site, and r0 holds the
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* saved LR as it was on entry to B, ie. the original return address at the
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* call site in A.
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*
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* Our job is to save the register state into a struct pt_regs (on the stack)
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* and then arrange for the ftrace function to be called.
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*/
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_GLOBAL(ftrace_caller)
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/* Save the original return address in A's stack frame */
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std r0,LRSAVE(r1)
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/* Create our stack frame + pt_regs */
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stdu r1,-SWITCH_FRAME_SIZE(r1)
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/* Save all gprs to pt_regs */
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SAVE_8GPRS(0,r1)
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SAVE_8GPRS(8,r1)
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SAVE_8GPRS(16,r1)
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SAVE_8GPRS(24,r1)
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/* Load special regs for save below */
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mfmsr r8
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mfctr r9
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mfxer r10
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mfcr r11
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/* Get the _mcount() call site out of LR */
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mflr r7
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/* Save it as pt_regs->nip & pt_regs->link */
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std r7, _NIP(r1)
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std r7, _LINK(r1)
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/* Save callee's TOC in the ABI compliant location */
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std r2, 24(r1)
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ld r2,PACATOC(r13) /* get kernel TOC in r2 */
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addis r3,r2,function_trace_op@toc@ha
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addi r3,r3,function_trace_op@toc@l
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ld r5,0(r3)
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/* Calculate ip from nip-4 into r3 for call below */
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subi r3, r7, MCOUNT_INSN_SIZE
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/* Put the original return address in r4 as parent_ip */
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mr r4, r0
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/* Save special regs */
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std r8, _MSR(r1)
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std r9, _CTR(r1)
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std r10, _XER(r1)
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std r11, _CCR(r1)
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/* Load &pt_regs in r6 for call below */
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addi r6, r1 ,STACK_FRAME_OVERHEAD
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/* ftrace_call(r3, r4, r5, r6) */
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.globl ftrace_call
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ftrace_call:
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bl ftrace_stub
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nop
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/* Load ctr with the possibly modified NIP */
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ld r3, _NIP(r1)
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mtctr r3
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/* Restore gprs */
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REST_8GPRS(0,r1)
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REST_8GPRS(8,r1)
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REST_8GPRS(16,r1)
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REST_8GPRS(24,r1)
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/* Restore callee's TOC */
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ld r2, 24(r1)
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/* Pop our stack frame */
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addi r1, r1, SWITCH_FRAME_SIZE
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/* Restore original LR for return to B */
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ld r0, LRSAVE(r1)
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mtlr r0
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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stdu r1, -112(r1)
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.globl ftrace_graph_call
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ftrace_graph_call:
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b ftrace_graph_stub
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_GLOBAL(ftrace_graph_stub)
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addi r1, r1, 112
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#endif
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ld r0,LRSAVE(r1) /* restore callee's lr at _mcount site */
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mtlr r0
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bctr /* jump after _mcount site */
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#endif /* CC_USING_MPROFILE_KERNEL */
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||||
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||||
_GLOBAL(ftrace_stub)
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blr
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||||
#else
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||||
@ -1213,6 +1326,7 @@ _GLOBAL(ftrace_stub)
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#endif /* CONFIG_DYNAMIC_FTRACE */
|
||||
|
||||
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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||||
#ifndef CC_USING_MPROFILE_KERNEL
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||||
_GLOBAL(ftrace_graph_caller)
|
||||
/* load r4 with local address */
|
||||
ld r4, 128(r1)
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||||
@ -1237,6 +1351,56 @@ _GLOBAL(ftrace_graph_caller)
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||||
addi r1, r1, 112
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||||
blr
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||||
|
||||
#else /* CC_USING_MPROFILE_KERNEL */
|
||||
_GLOBAL(ftrace_graph_caller)
|
||||
/* with -mprofile-kernel, parameter regs are still alive at _mcount */
|
||||
std r10, 104(r1)
|
||||
std r9, 96(r1)
|
||||
std r8, 88(r1)
|
||||
std r7, 80(r1)
|
||||
std r6, 72(r1)
|
||||
std r5, 64(r1)
|
||||
std r4, 56(r1)
|
||||
std r3, 48(r1)
|
||||
|
||||
/* Save callee's TOC in the ABI compliant location */
|
||||
std r2, 24(r1)
|
||||
ld r2, PACATOC(r13) /* get kernel TOC in r2 */
|
||||
|
||||
mfctr r4 /* ftrace_caller has moved local addr here */
|
||||
std r4, 40(r1)
|
||||
mflr r3 /* ftrace_caller has restored LR from stack */
|
||||
subi r4, r4, MCOUNT_INSN_SIZE
|
||||
|
||||
bl prepare_ftrace_return
|
||||
nop
|
||||
|
||||
/*
|
||||
* prepare_ftrace_return gives us the address we divert to.
|
||||
* Change the LR to this.
|
||||
*/
|
||||
mtlr r3
|
||||
|
||||
ld r0, 40(r1)
|
||||
mtctr r0
|
||||
ld r10, 104(r1)
|
||||
ld r9, 96(r1)
|
||||
ld r8, 88(r1)
|
||||
ld r7, 80(r1)
|
||||
ld r6, 72(r1)
|
||||
ld r5, 64(r1)
|
||||
ld r4, 56(r1)
|
||||
ld r3, 48(r1)
|
||||
|
||||
/* Restore callee's TOC */
|
||||
ld r2, 24(r1)
|
||||
|
||||
addi r1, r1, 112
|
||||
mflr r0
|
||||
std r0, LRSAVE(r1)
|
||||
bctr
|
||||
#endif /* CC_USING_MPROFILE_KERNEL */
|
||||
|
||||
_GLOBAL(return_to_handler)
|
||||
/* need to save return values */
|
||||
std r4, -32(r1)
|
||||
|
||||
@ -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) {
|
||||
pr_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 +109,15 @@ static int
|
||||
__ftrace_make_nop(struct module *mod,
|
||||
struct dyn_ftrace *rec, unsigned long addr)
|
||||
{
|
||||
unsigned int op;
|
||||
unsigned long entry, ptr;
|
||||
unsigned long entry, ptr, tramp;
|
||||
unsigned long ip = rec->ip;
|
||||
void *tramp;
|
||||
unsigned int op, pop;
|
||||
|
||||
/* read where this goes */
|
||||
if (probe_kernel_read(&op, (void *)ip, sizeof(int)))
|
||||
if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
|
||||
pr_err("Fetching opcode failed.\n");
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
/* Make sure that that this is still a 24bit jump */
|
||||
if (!is_bl_op(op)) {
|
||||
@ -122,14 +126,9 @@ __ftrace_make_nop(struct module *mod,
|
||||
}
|
||||
|
||||
/* lets find where the pointer goes */
|
||||
tramp = (void *)find_bl_target(ip, op);
|
||||
tramp = find_bl_target(ip, op);
|
||||
|
||||
pr_devel("ip:%lx jumps to %p", ip, tramp);
|
||||
|
||||
if (!is_module_trampoline(tramp)) {
|
||||
pr_err("Not a trampoline\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
pr_devel("ip:%lx jumps to %lx", ip, tramp);
|
||||
|
||||
if (module_trampoline_target(mod, tramp, &ptr)) {
|
||||
pr_err("Failed to get trampoline target\n");
|
||||
@ -158,10 +157,42 @@ __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 = PPC_INST_BRANCH | 8; /* 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)) {
|
||||
pr_err("Fetching op failed.\n");
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
if (op != PPC_INST_LD_TOC) {
|
||||
unsigned int inst;
|
||||
|
||||
if (probe_kernel_read(&inst, (void *)(ip - 4), 4)) {
|
||||
pr_err("Fetching instruction at %lx failed.\n", ip - 4);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
/* We expect either a mlfr r0, or a std r0, LRSAVE(r1) */
|
||||
if (inst != PPC_INST_MFLR && inst != PPC_INST_STD_LR) {
|
||||
pr_err("Unexpected instructions around bl _mcount\n"
|
||||
"when enabling dynamic ftrace!\t"
|
||||
"(%08x,bl,%08x)\n", inst, op);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* When using -mkernel_profile there is no load to jump over */
|
||||
pop = PPC_INST_NOP;
|
||||
}
|
||||
|
||||
if (patch_instruction((unsigned int *)ip, pop)) {
|
||||
pr_err("Patching NOP failed.\n");
|
||||
return -EPERM;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
@ -287,6 +318,39 @@ int ftrace_make_nop(struct module *mod,
|
||||
|
||||
#ifdef CONFIG_MODULES
|
||||
#ifdef CONFIG_PPC64
|
||||
/*
|
||||
* Examine the existing instructions for __ftrace_make_call.
|
||||
* They should effectively be a NOP, and follow formal constraints,
|
||||
* depending on the ABI. Return false if they don't.
|
||||
*/
|
||||
#ifndef CC_USING_MPROFILE_KERNEL
|
||||
static int
|
||||
expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1)
|
||||
{
|
||||
/*
|
||||
* We expect to see:
|
||||
*
|
||||
* b +8
|
||||
* ld r2,XX(r1)
|
||||
*
|
||||
* The load offset is different depending on the ABI. For simplicity
|
||||
* just mask it out when doing the compare.
|
||||
*/
|
||||
if ((op0 != 0x48000008) || ((op1 & 0xffff0000) != 0xe8410000))
|
||||
return 0;
|
||||
return 1;
|
||||
}
|
||||
#else
|
||||
static int
|
||||
expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1)
|
||||
{
|
||||
/* look for patched "NOP" on ppc64 with -mprofile-kernel */
|
||||
if (op0 != PPC_INST_NOP)
|
||||
return 0;
|
||||
return 1;
|
||||
}
|
||||
#endif
|
||||
|
||||
static int
|
||||
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
||||
{
|
||||
@ -297,17 +361,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
||||
if (probe_kernel_read(op, ip, sizeof(op)))
|
||||
return -EFAULT;
|
||||
|
||||
/*
|
||||
* We expect to see:
|
||||
*
|
||||
* b +8
|
||||
* ld r2,XX(r1)
|
||||
*
|
||||
* The load offset is different depending on the ABI. For simplicity
|
||||
* just mask it out when doing the compare.
|
||||
*/
|
||||
if ((op[0] != 0x48000008) || ((op[1] & 0xffff0000) != 0xe8410000)) {
|
||||
pr_err("Unexpected call sequence: %x %x\n", op[0], op[1]);
|
||||
if (!expected_nop_sequence(ip, op[0], op[1])) {
|
||||
pr_err("Unexpected call sequence at %p: %x %x\n",
|
||||
ip, op[0], op[1]);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
@ -330,7 +386,16 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
||||
|
||||
return 0;
|
||||
}
|
||||
#else
|
||||
|
||||
#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
|
||||
|
||||
#else /* !CONFIG_PPC64: */
|
||||
static int
|
||||
__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
||||
{
|
||||
@ -455,20 +520,13 @@ void ftrace_replace_code(int enable)
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Use the default ftrace_modify_all_code, but without
|
||||
* stop_machine().
|
||||
*/
|
||||
void arch_ftrace_update_code(int command)
|
||||
{
|
||||
if (command & FTRACE_UPDATE_CALLS)
|
||||
ftrace_replace_code(1);
|
||||
else if (command & FTRACE_DISABLE_CALLS)
|
||||
ftrace_replace_code(0);
|
||||
|
||||
if (command & FTRACE_UPDATE_TRACE_FUNC)
|
||||
ftrace_update_ftrace_func(ftrace_trace_function);
|
||||
|
||||
if (command & FTRACE_START_FUNC_RET)
|
||||
ftrace_enable_ftrace_graph_caller();
|
||||
else if (command & FTRACE_STOP_FUNC_RET)
|
||||
ftrace_disable_ftrace_graph_caller();
|
||||
ftrace_modify_all_code(command);
|
||||
}
|
||||
|
||||
int __init ftrace_dyn_arch_init(void)
|
||||
|
||||
@ -47,6 +47,11 @@ int module_finalize(const Elf_Ehdr *hdr,
|
||||
const Elf_Shdr *sechdrs, struct module *me)
|
||||
{
|
||||
const Elf_Shdr *sect;
|
||||
int rc;
|
||||
|
||||
rc = module_finalize_ftrace(me, sechdrs);
|
||||
if (rc)
|
||||
return rc;
|
||||
|
||||
/* Apply feature fixups */
|
||||
sect = find_section(hdr, sechdrs, "__ftr_fixup");
|
||||
|
||||
@ -181,7 +181,7 @@ static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val)
|
||||
/* Set up a trampoline in the PLT to bounce us to the distant function */
|
||||
static uint32_t do_plt_call(void *location,
|
||||
Elf32_Addr val,
|
||||
Elf32_Shdr *sechdrs,
|
||||
const Elf32_Shdr *sechdrs,
|
||||
struct module *mod)
|
||||
{
|
||||
struct ppc_plt_entry *entry;
|
||||
@ -294,11 +294,19 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
|
||||
return -ENOEXEC;
|
||||
}
|
||||
}
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
module->arch.tramp =
|
||||
do_plt_call(module->core_layout.base,
|
||||
(unsigned long)ftrace_caller,
|
||||
sechdrs, module);
|
||||
#endif
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs)
|
||||
{
|
||||
module->arch.tramp = do_plt_call(module->core_layout.base,
|
||||
(unsigned long)ftrace_caller,
|
||||
sechdrs, module);
|
||||
if (!module->arch.tramp)
|
||||
return -ENOENT;
|
||||
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
||||
@ -31,6 +31,7 @@
|
||||
#include <asm/code-patching.h>
|
||||
#include <linux/sort.h>
|
||||
#include <asm/setup.h>
|
||||
#include <asm/sections.h>
|
||||
|
||||
/* FIXME: We don't do .init separately. To do this, we'd need to have
|
||||
a separate r2 value in the init and core section, and stub between
|
||||
@ -41,7 +42,6 @@
|
||||
--RR. */
|
||||
|
||||
#if defined(_CALL_ELF) && _CALL_ELF == 2
|
||||
#define R2_STACK_OFFSET 24
|
||||
|
||||
/* An address is simply the address of the function. */
|
||||
typedef unsigned long func_desc_t;
|
||||
@ -73,7 +73,6 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
|
||||
return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
|
||||
}
|
||||
#else
|
||||
#define R2_STACK_OFFSET 40
|
||||
|
||||
/* An address is address of the OPD entry, which contains address of fn. */
|
||||
typedef struct ppc64_opd_entry func_desc_t;
|
||||
@ -96,6 +95,8 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
|
||||
}
|
||||
#endif
|
||||
|
||||
#define STUB_MAGIC 0x73747562 /* stub */
|
||||
|
||||
/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
|
||||
the kernel itself). But on PPC64, these need to be used for every
|
||||
jump, actually, to reset r2 (TOC+0x8000). */
|
||||
@ -105,7 +106,8 @@ struct ppc64_stub_entry
|
||||
* need 6 instructions on ABIv2 but we always allocate 7 so
|
||||
* so we don't have to modify the trampoline load instruction. */
|
||||
u32 jump[7];
|
||||
u32 unused;
|
||||
/* Used by ftrace to identify stubs */
|
||||
u32 magic;
|
||||
/* Data for the above code */
|
||||
func_desc_t funcdata;
|
||||
};
|
||||
@ -139,70 +141,39 @@ static u32 ppc64_stub_insns[] = {
|
||||
};
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
|
||||
static u32 ppc64_stub_mask[] = {
|
||||
0xffff0000,
|
||||
0xffff0000,
|
||||
0xffffffff,
|
||||
0xffffffff,
|
||||
#if !defined(_CALL_ELF) || _CALL_ELF != 2
|
||||
0xffffffff,
|
||||
#endif
|
||||
0xffffffff,
|
||||
0xffffffff
|
||||
};
|
||||
|
||||
bool is_module_trampoline(u32 *p)
|
||||
{
|
||||
unsigned int i;
|
||||
u32 insns[ARRAY_SIZE(ppc64_stub_insns)];
|
||||
|
||||
BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask));
|
||||
|
||||
if (probe_kernel_read(insns, p, sizeof(insns)))
|
||||
return -EFAULT;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) {
|
||||
u32 insna = insns[i];
|
||||
u32 insnb = ppc64_stub_insns[i];
|
||||
u32 mask = ppc64_stub_mask[i];
|
||||
|
||||
if ((insna & mask) != (insnb & mask))
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
int module_trampoline_target(struct module *mod, u32 *trampoline,
|
||||
int module_trampoline_target(struct module *mod, unsigned long addr,
|
||||
unsigned long *target)
|
||||
{
|
||||
u32 buf[2];
|
||||
u16 upper, lower;
|
||||
long offset;
|
||||
void *toc_entry;
|
||||
struct ppc64_stub_entry *stub;
|
||||
func_desc_t funcdata;
|
||||
u32 magic;
|
||||
|
||||
if (probe_kernel_read(buf, trampoline, sizeof(buf)))
|
||||
if (!within_module_core(addr, mod)) {
|
||||
pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
upper = buf[0] & 0xffff;
|
||||
lower = buf[1] & 0xffff;
|
||||
stub = (struct ppc64_stub_entry *)addr;
|
||||
|
||||
/* perform the addis/addi, both signed */
|
||||
offset = ((short)upper << 16) + (short)lower;
|
||||
|
||||
/*
|
||||
* Now get the address this trampoline jumps to. This
|
||||
* is always 32 bytes into our trampoline stub.
|
||||
*/
|
||||
toc_entry = (void *)mod->arch.toc + offset + 32;
|
||||
|
||||
if (probe_kernel_read(target, toc_entry, sizeof(*target)))
|
||||
if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) {
|
||||
pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
if (magic != STUB_MAGIC) {
|
||||
pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) {
|
||||
pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
*target = stub_func_addr(funcdata);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
/* Count how many different 24-bit relocations (different symbol,
|
||||
@ -413,7 +384,7 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
|
||||
/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
|
||||
gives the value maximum span in an instruction which uses a signed
|
||||
offset) */
|
||||
static inline unsigned long my_r2(Elf64_Shdr *sechdrs, struct module *me)
|
||||
static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
|
||||
{
|
||||
return sechdrs[me->arch.toc_section].sh_addr + 0x8000;
|
||||
}
|
||||
@ -426,7 +397,7 @@ static inline unsigned long my_r2(Elf64_Shdr *sechdrs, struct module *me)
|
||||
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
|
||||
|
||||
/* Patch stub to reference function and correct r2 value. */
|
||||
static inline int create_stub(Elf64_Shdr *sechdrs,
|
||||
static inline int create_stub(const Elf64_Shdr *sechdrs,
|
||||
struct ppc64_stub_entry *entry,
|
||||
unsigned long addr,
|
||||
struct module *me)
|
||||
@ -447,12 +418,14 @@ static inline int create_stub(Elf64_Shdr *sechdrs,
|
||||
entry->jump[0] |= PPC_HA(reladdr);
|
||||
entry->jump[1] |= PPC_LO(reladdr);
|
||||
entry->funcdata = func_desc(addr);
|
||||
entry->magic = STUB_MAGIC;
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
/* Create stub to jump to function described in this OPD/ptr: we need the
|
||||
stub to set up the TOC ptr (r2) for the function. */
|
||||
static unsigned long stub_for_addr(Elf64_Shdr *sechdrs,
|
||||
static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
|
||||
unsigned long addr,
|
||||
struct module *me)
|
||||
{
|
||||
@ -476,17 +449,60 @@ static unsigned long stub_for_addr(Elf64_Shdr *sechdrs,
|
||||
return (unsigned long)&stubs[i];
|
||||
}
|
||||
|
||||
#ifdef CC_USING_MPROFILE_KERNEL
|
||||
static bool is_early_mcount_callsite(u32 *instruction)
|
||||
{
|
||||
/*
|
||||
* Check if this is one of the -mprofile-kernel sequences.
|
||||
*/
|
||||
if (instruction[-1] == PPC_INST_STD_LR &&
|
||||
instruction[-2] == PPC_INST_MFLR)
|
||||
return true;
|
||||
|
||||
if (instruction[-1] == PPC_INST_MFLR)
|
||||
return true;
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
/*
|
||||
* In case of _mcount calls, do not save the current callee's TOC (in r2) into
|
||||
* the original caller's stack frame. If we did we would clobber the saved TOC
|
||||
* value of the original caller.
|
||||
*/
|
||||
static void squash_toc_save_inst(const char *name, unsigned long addr)
|
||||
{
|
||||
struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
|
||||
|
||||
/* Only for calls to _mcount */
|
||||
if (strcmp("_mcount", name) != 0)
|
||||
return;
|
||||
|
||||
stub->jump[2] = PPC_INST_NOP;
|
||||
}
|
||||
#else
|
||||
static void squash_toc_save_inst(const char *name, unsigned long addr) { }
|
||||
|
||||
/* without -mprofile-kernel, mcount calls are never early */
|
||||
static bool is_early_mcount_callsite(u32 *instruction)
|
||||
{
|
||||
return false;
|
||||
}
|
||||
#endif
|
||||
|
||||
/* We expect a noop next: if it is, replace it with instruction to
|
||||
restore r2. */
|
||||
static int restore_r2(u32 *instruction, struct module *me)
|
||||
{
|
||||
if (*instruction != PPC_INST_NOP) {
|
||||
if (is_early_mcount_callsite(instruction - 1))
|
||||
return 1;
|
||||
pr_err("%s: Expect noop after relocate, got %08x\n",
|
||||
me->name, *instruction);
|
||||
return 0;
|
||||
}
|
||||
/* ld r2,R2_STACK_OFFSET(r1) */
|
||||
*instruction = 0xe8410000 | R2_STACK_OFFSET;
|
||||
*instruction = PPC_INST_LD_TOC;
|
||||
return 1;
|
||||
}
|
||||
|
||||
@ -611,6 +627,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
|
||||
return -ENOENT;
|
||||
if (!restore_r2((u32 *)location + 1, me))
|
||||
return -ENOEXEC;
|
||||
|
||||
squash_toc_save_inst(strtab + sym->st_name, value);
|
||||
} else
|
||||
value += local_entry_offset(sym);
|
||||
|
||||
@ -693,12 +711,84 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
me->arch.toc = my_r2(sechdrs, me);
|
||||
me->arch.tramp = stub_for_addr(sechdrs,
|
||||
(unsigned long)ftrace_caller,
|
||||
me);
|
||||
|
||||
#ifdef CC_USING_MPROFILE_KERNEL
|
||||
|
||||
#define PACATOC offsetof(struct paca_struct, kernel_toc)
|
||||
|
||||
/*
|
||||
* For mprofile-kernel we use a special stub for ftrace_caller() because we
|
||||
* can't rely on r2 containing this module's TOC when we enter the stub.
|
||||
*
|
||||
* That can happen if the function calling us didn't need to use the toc. In
|
||||
* that case it won't have setup r2, and the r2 value will be either the
|
||||
* kernel's toc, or possibly another modules toc.
|
||||
*
|
||||
* To deal with that this stub uses the kernel toc, which is always accessible
|
||||
* via the paca (in r13). The target (ftrace_caller()) is responsible for
|
||||
* saving and restoring the toc before returning.
|
||||
*/
|
||||
static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
|
||||
{
|
||||
struct ppc64_stub_entry *entry;
|
||||
unsigned int i, num_stubs;
|
||||
static u32 stub_insns[] = {
|
||||
0xe98d0000 | PACATOC, /* ld r12,PACATOC(r13) */
|
||||
0x3d8c0000, /* addis r12,r12,<high> */
|
||||
0x398c0000, /* addi r12,r12,<low> */
|
||||
0x7d8903a6, /* mtctr r12 */
|
||||
0x4e800420, /* bctr */
|
||||
};
|
||||
long reladdr;
|
||||
|
||||
num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
|
||||
|
||||
/* Find the next available stub entry */
|
||||
entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
|
||||
for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
|
||||
|
||||
if (i >= num_stubs) {
|
||||
pr_err("%s: Unable to find a free slot for ftrace stub.\n", me->name);
|
||||
return 0;
|
||||
}
|
||||
|
||||
memcpy(entry->jump, stub_insns, sizeof(stub_insns));
|
||||
|
||||
/* Stub uses address relative to kernel toc (from the paca) */
|
||||
reladdr = (unsigned long)ftrace_caller - kernel_toc_addr();
|
||||
if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
|
||||
pr_err("%s: Address of ftrace_caller out of range of kernel_toc.\n", me->name);
|
||||
return 0;
|
||||
}
|
||||
|
||||
entry->jump[1] |= PPC_HA(reladdr);
|
||||
entry->jump[2] |= PPC_LO(reladdr);
|
||||
|
||||
/* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
|
||||
entry->funcdata = func_desc((unsigned long)ftrace_caller);
|
||||
entry->magic = STUB_MAGIC;
|
||||
|
||||
return (unsigned long)entry;
|
||||
}
|
||||
#else
|
||||
static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
|
||||
{
|
||||
return stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me);
|
||||
}
|
||||
#endif
|
||||
|
||||
int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
|
||||
{
|
||||
mod->arch.toc = my_r2(sechdrs, mod);
|
||||
mod->arch.tramp = create_ftrace_stub(sechdrs, mod);
|
||||
|
||||
if (!mod->arch.tramp)
|
||||
return -ENOENT;
|
||||
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
||||
@ -17,10 +17,6 @@
|
||||
#include <asm/pgtable.h>
|
||||
#include <asm/kexec.h>
|
||||
|
||||
/* This symbol is provided by the linker - let it fill in the paca
|
||||
* field correctly */
|
||||
extern unsigned long __toc_start;
|
||||
|
||||
#ifdef CONFIG_PPC_BOOK3S
|
||||
|
||||
/*
|
||||
@ -149,11 +145,6 @@ EXPORT_SYMBOL(paca);
|
||||
|
||||
void __init initialise_paca(struct paca_struct *new_paca, int cpu)
|
||||
{
|
||||
/* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
|
||||
* of the TOC can be addressed using a single machine instruction.
|
||||
*/
|
||||
unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
|
||||
|
||||
#ifdef CONFIG_PPC_BOOK3S
|
||||
new_paca->lppaca_ptr = new_lppaca(cpu);
|
||||
#else
|
||||
@ -161,7 +152,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu)
|
||||
#endif
|
||||
new_paca->lock_token = 0x8000;
|
||||
new_paca->paca_index = cpu;
|
||||
new_paca->kernel_toc = kernel_toc;
|
||||
new_paca->kernel_toc = kernel_toc_addr();
|
||||
new_paca->kernelbase = (unsigned long) _stext;
|
||||
/* Only set MSR:IR/DR when MMU is initialized */
|
||||
new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
|
||||
|
||||
@ -6,8 +6,8 @@ subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
|
||||
|
||||
ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
|
||||
|
||||
CFLAGS_REMOVE_code-patching.o = -pg
|
||||
CFLAGS_REMOVE_feature-fixups.o = -pg
|
||||
CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
|
||||
CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
|
||||
|
||||
obj-y += string.o alloc.o crtsavres.o ppc_ksyms.o code-patching.o \
|
||||
feature-fixups.o
|
||||
|
||||
@ -2,7 +2,7 @@ CFLAGS_bootx_init.o += -fPIC
|
||||
|
||||
ifdef CONFIG_FUNCTION_TRACER
|
||||
# Do not trace early boot code
|
||||
CFLAGS_REMOVE_bootx_init.o = -pg -mno-sched-epilog
|
||||
CFLAGS_REMOVE_bootx_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
|
||||
endif
|
||||
|
||||
obj-y += pic.o setup.o time.o feature.o pci.o \
|
||||
|
||||
23
arch/powerpc/scripts/gcc-check-mprofile-kernel.sh
Executable file
23
arch/powerpc/scripts/gcc-check-mprofile-kernel.sh
Executable file
@ -0,0 +1,23 @@
|
||||
#!/bin/bash
|
||||
|
||||
set -e
|
||||
set -o pipefail
|
||||
|
||||
# To debug, uncomment the following line
|
||||
# set -x
|
||||
|
||||
# Test whether the compile option -mprofile-kernel exists and generates
|
||||
# profiling code (ie. a call to _mcount()).
|
||||
echo "int func() { return 0; }" | \
|
||||
$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
|
||||
grep -q "_mcount"
|
||||
|
||||
# Test whether the notrace attribute correctly suppresses calls to _mcount().
|
||||
|
||||
echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" | \
|
||||
$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
|
||||
grep -q "_mcount" && \
|
||||
exit 1
|
||||
|
||||
echo "OK"
|
||||
exit 0
|
||||
Loading…
Reference in New Issue
Block a user