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1389f17937
arch_ftrace_get_regs is supposed to return a struct pt_regs pointer
only if the pt_regs structure contains all register contents, which
means it must have been populated when created via ftrace_regs_caller.
If it was populated via ftrace_caller the contents are not complete
(the psw mask part is missing), and therefore a NULL pointer needs be
returned.
The current code incorrectly always returns a struct pt_regs pointer.
Fix this by adding another pt_regs flag which indicates if the
contents are complete, and fix arch_ftrace_get_regs accordingly.
Fixes: 894979689d ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations")
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_S390_FTRACE_H
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#define _ASM_S390_FTRACE_H
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#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#define MCOUNT_INSN_SIZE 6
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_CC_IS_CLANG
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/* https://bugs.llvm.org/show_bug.cgi?id=41424 */
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#define ftrace_return_address(n) 0UL
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#else
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#define ftrace_return_address(n) __builtin_return_address(n)
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#endif
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void ftrace_caller(void);
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extern void *ftrace_func;
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struct dyn_arch_ftrace { };
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#define MCOUNT_ADDR 0
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#define FTRACE_ADDR ((unsigned long)ftrace_caller)
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#define KPROBE_ON_FTRACE_NOP 0
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#define KPROBE_ON_FTRACE_CALL 1
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struct module;
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struct dyn_ftrace;
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bool ftrace_need_init_nop(void);
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#define ftrace_need_init_nop ftrace_need_init_nop
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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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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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return addr;
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}
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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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struct pt_regs *regs = &fregs->regs;
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if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
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return regs;
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return NULL;
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}
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static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *fregs,
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unsigned long ip)
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{
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fregs->regs.psw.addr = ip;
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}
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/*
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* When an ftrace registered caller is tracing a function that is
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* also set by a register_ftrace_direct() call, it needs to be
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* differentiated in the ftrace_caller trampoline. To do this,
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* place the direct caller in the ORIG_GPR2 part of pt_regs. This
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* tells the ftrace_caller that there's a direct caller.
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*/
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static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
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{
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regs->orig_gpr2 = addr;
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}
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/*
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* Even though the system call numbers are identical for s390/s390x a
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* different system call table is used for compat tasks. This may lead
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* to e.g. incorrect or missing trace event sysfs files.
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* Therefore simply do not trace compat system calls at all.
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* See kernel/trace/trace_syscalls.c.
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*/
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#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
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static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
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{
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return is_compat_task();
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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,
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const char *name)
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{
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/*
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* Skip __s390_ and __s390x_ prefix - due to compat wrappers
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* and aliasing some symbols of 64 bit system call functions
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* may get the __s390_ prefix instead of the __s390x_ prefix.
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*/
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return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
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}
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#endif /* __ASSEMBLY__ */
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#ifdef CONFIG_FUNCTION_TRACER
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#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
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#ifndef CC_USING_HOTPATCH
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#define FTRACE_GEN_MCOUNT_RECORD(name) \
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.section __mcount_loc, "a", @progbits; \
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.quad name; \
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.previous;
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#else /* !CC_USING_HOTPATCH */
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#define FTRACE_GEN_MCOUNT_RECORD(name)
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#endif /* !CC_USING_HOTPATCH */
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#define FTRACE_GEN_NOP_ASM(name) \
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FTRACE_GEN_MCOUNT_RECORD(name) \
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FTRACE_NOP_INSN
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#else /* CONFIG_FUNCTION_TRACER */
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#define FTRACE_GEN_NOP_ASM(name)
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#endif /* CONFIG_FUNCTION_TRACER */
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#endif /* _ASM_S390_FTRACE_H */
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