0f71dcfb4a
GCC v13.1 updated support for -fpatchable-function-entry on ppc64le to emit nops after the local entry point, rather than before it. This allows us to use this in the kernel for ftrace purposes. A new script is added under arch/powerpc/tools/ to help detect if nops are emitted after the function local entry point, or before the global entry point. With -fpatchable-function-entry, we no longer have the profiling instructions generated at function entry, so we only need to validate the presence of two nops at the ftrace location in ftrace_init_nop(). We patch the preceding instruction with 'mflr r0' to match the -mprofile-kernel ABI for subsequent ftrace use. This changes the profiling instructions used on ppc32. The default -pg option emits an additional 'stw' instruction after 'mflr r0' and before the branch to _mcount 'bl _mcount'. This is very similar to the original -mprofile-kernel implementation on ppc64le, where an additional 'std' instruction was used to save LR to its save location in the caller's stackframe. Subsequently, this additional store was removed in later compiler versions for performance reasons. The same reasons apply for ppc32 so we only patch in a 'mflr r0'. Signed-off-by: Naveen N Rao <naveen@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/68586d22981a2c3bb45f27a2b621173d10a7d092.1687166935.git.naveen@kernel.org
151 lines
4.2 KiB
C
151 lines
4.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_FTRACE
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#define _ASM_POWERPC_FTRACE
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#include <asm/types.h>
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#ifdef CONFIG_FUNCTION_TRACER
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#define MCOUNT_ADDR ((unsigned long)(_mcount))
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#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
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#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
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/* Ignore unused weak functions which will have larger offsets */
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#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY)
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#define FTRACE_MCOUNT_MAX_OFFSET 16
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#elif defined(CONFIG_PPC32)
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#define FTRACE_MCOUNT_MAX_OFFSET 8
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#endif
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#ifndef __ASSEMBLY__
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extern void _mcount(void);
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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if (IS_ENABLED(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY))
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addr += MCOUNT_INSN_SIZE;
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return addr;
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}
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unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
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unsigned long sp);
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struct module;
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struct dyn_ftrace;
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struct dyn_arch_ftrace {
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struct module *mod;
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};
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
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#define ftrace_need_init_nop() (true)
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int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
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#define ftrace_init_nop ftrace_init_nop
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struct ftrace_regs {
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struct pt_regs regs;
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};
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static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
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{
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/* We clear regs.msr in ftrace_call */
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return fregs->regs.msr ? &fregs->regs : NULL;
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}
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static __always_inline void
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ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
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unsigned long ip)
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{
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regs_set_return_ip(&fregs->regs, ip);
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}
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static __always_inline unsigned long
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ftrace_regs_get_instruction_pointer(struct ftrace_regs *fregs)
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{
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return instruction_pointer(&fregs->regs);
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}
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#define ftrace_regs_get_argument(fregs, n) \
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regs_get_kernel_argument(&(fregs)->regs, n)
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#define ftrace_regs_get_stack_pointer(fregs) \
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kernel_stack_pointer(&(fregs)->regs)
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#define ftrace_regs_return_value(fregs) \
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regs_return_value(&(fregs)->regs)
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#define ftrace_regs_set_return_value(fregs, ret) \
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regs_set_return_value(&(fregs)->regs, ret)
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#define ftrace_override_function_with_return(fregs) \
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override_function_with_return(&(fregs)->regs)
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#define ftrace_regs_query_register_offset(name) \
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regs_query_register_offset(name)
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struct ftrace_ops;
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#define ftrace_graph_func ftrace_graph_func
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void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct ftrace_regs *fregs);
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#endif
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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 /* CONFIG_FUNCTION_TRACER */
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_FTRACE_SYSCALLS
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/*
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* Some syscall entry functions on powerpc start with "ppc_" (fork and clone,
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* for instance) or ppc32_/ppc64_. We should also match the sys_ variant with
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* those.
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*/
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#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
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static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
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{
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return !strcmp(sym, name) ||
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(!strncmp(sym, "__se_sys", 8) && !strcmp(sym + 5, name)) ||
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(!strncmp(sym, "ppc_", 4) && !strcmp(sym + 4, name + 4)) ||
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(!strncmp(sym, "ppc32_", 6) && !strcmp(sym + 6, name + 4)) ||
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(!strncmp(sym, "ppc64_", 6) && !strcmp(sym + 6, name + 4));
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}
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#endif /* CONFIG_FTRACE_SYSCALLS */
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#if defined(CONFIG_PPC64) && defined(CONFIG_FUNCTION_TRACER)
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#include <asm/paca.h>
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static inline void this_cpu_disable_ftrace(void)
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{
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get_paca()->ftrace_enabled = 0;
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}
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static inline void this_cpu_enable_ftrace(void)
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{
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get_paca()->ftrace_enabled = 1;
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}
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/* Disable ftrace on this CPU if possible (may not be implemented) */
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static inline void this_cpu_set_ftrace_enabled(u8 ftrace_enabled)
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{
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get_paca()->ftrace_enabled = ftrace_enabled;
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}
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static inline u8 this_cpu_get_ftrace_enabled(void)
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{
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return get_paca()->ftrace_enabled;
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}
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#else /* CONFIG_PPC64 */
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static inline void this_cpu_disable_ftrace(void) { }
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static inline void this_cpu_enable_ftrace(void) { }
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static inline void this_cpu_set_ftrace_enabled(u8 ftrace_enabled) { }
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static inline u8 this_cpu_get_ftrace_enabled(void) { return 1; }
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#endif /* CONFIG_PPC64 */
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#ifdef CONFIG_FUNCTION_TRACER
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extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[];
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void ftrace_free_init_tramp(void);
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#else
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static inline void ftrace_free_init_tramp(void) { }
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#endif
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_POWERPC_FTRACE */
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