6845d64d51
Commit41918ec82e("ARM: ftrace: enable the graph tracer with the EABI unwinder") removed the dummy version of return_address() that was provided for the CONFIG_ARM_UNWIND=y case, on the assumption that the removal of the kernel_text_address() call from unwind_frame() in the preceding patch made it safe to do so. However, this turns out not to be the case: Corentin reports warnings about suspicious RCU usage and other strange behavior that seems to originate in the stack unwinding that occurs in return_address(). Given that the function graph tracer (which is what these changes were enabling for CONFIG_ARM_UNWIND=y builds) does not appear to care about this distinction, let's revert return_address() to the old state. Cc: Corentin Labbe <clabbe.montjoie@gmail.com> Fixes:41918ec82e("ARM: ftrace: enable the graph tracer with the EABI unwinder") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_ARM_FTRACE
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#define _ASM_ARM_FTRACE
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#define HAVE_FUNCTION_GRAPH_FP_TEST
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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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#ifdef CONFIG_FUNCTION_TRACER
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#define MCOUNT_ADDR ((unsigned long)(__gnu_mcount_nc))
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#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
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#ifndef __ASSEMBLY__
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extern void __gnu_mcount_nc(void);
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#ifdef CONFIG_DYNAMIC_FTRACE
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struct dyn_arch_ftrace {
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#ifdef CONFIG_ARM_MODULE_PLTS
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struct module *mod;
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#endif
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};
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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/* With Thumb-2, the recorded addresses have the lsb set */
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return addr & ~1;
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}
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#endif
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#endif
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#endif
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#ifndef __ASSEMBLY__
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#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND)
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/*
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* return_address uses walk_stackframe to do it's work. If both
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* CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=y walk_stackframe uses unwind
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* information. For this to work in the function tracer many functions would
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* have to be marked with __notrace. So for now just depend on
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* !CONFIG_ARM_UNWIND.
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*/
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void *return_address(unsigned int);
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#else
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static inline void *return_address(unsigned int level)
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{
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return NULL;
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}
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#endif
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#define ftrace_return_address(n) return_address(n)
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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,
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const char *name)
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{
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if (!strcmp(sym, "sys_mmap2"))
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sym = "sys_mmap_pgoff";
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else if (!strcmp(sym, "sys_statfs64_wrapper"))
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sym = "sys_statfs64";
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else if (!strcmp(sym, "sys_fstatfs64_wrapper"))
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sym = "sys_fstatfs64";
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else if (!strcmp(sym, "sys_arm_fadvise64_64"))
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sym = "sys_fadvise64_64";
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/* Ignore case since sym may start with "SyS" instead of "sys" */
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return !strcasecmp(sym, name);
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}
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#endif /* ifndef __ASSEMBLY__ */
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#endif /* _ASM_ARM_FTRACE */
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