a846446b19
The result of in_compat_syscall() can be pictured as:
x86 platform:
---------------------------------------------------
| Arch\syscall | 64-bit | ia32 | x32 |
|-------------------------------------------------|
| x86_64 | false | true | true |
|-------------------------------------------------|
| i686 | | <true> | |
---------------------------------------------------
Other platforms:
-------------------------------------------
| Arch\syscall | 64-bit | compat |
|-----------------------------------------|
| 64-bit | false | true |
|-----------------------------------------|
| 32-bit(?) | | <false> |
-------------------------------------------
As seen, the result of in_compat_syscall() on generic 32-bit platform
differs from i686.
There is no reason for in_compat_syscall() == true on native i686. It also
easy to misread code if the result on native 32-bit platform differs
between arches.
Because of that non arch-specific code has many places with:
if (IS_ENABLED(CONFIG_COMPAT) && in_compat_syscall())
in different variations.
It looks-like the only non-x86 code which uses in_compat_syscall() not
under CONFIG_COMPAT guard is in amd/amdkfd. But according to the commit
a18069c132cb ("amdkfd: Disable support for 32-bit user processes"), it
actually should be disabled on native i686.
Rename in_compat_syscall() to in_32bit_syscall() for x86-specific code
and make in_compat_syscall() false under !CONFIG_COMPAT.
A follow on patch will clean up generic users which were forced to check
IS_ENABLED(CONFIG_COMPAT) with in_compat_syscall().
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-efi@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lkml.kernel.org/r/20181012134253.23266-2-dima@arista.com
86 lines
2.2 KiB
C
86 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_FTRACE_H
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#define _ASM_X86_FTRACE_H
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#ifdef CONFIG_FUNCTION_TRACER
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#ifdef CC_USING_FENTRY
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# define MCOUNT_ADDR ((unsigned long)(__fentry__))
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#else
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# define MCOUNT_ADDR ((unsigned long)(mcount))
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# define HAVE_FUNCTION_GRAPH_FP_TEST
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#endif
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#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
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#ifdef CONFIG_DYNAMIC_FTRACE
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#define ARCH_SUPPORTS_FTRACE_OPS 1
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#endif
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#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
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#ifndef __ASSEMBLY__
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extern void mcount(void);
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extern atomic_t modifying_ftrace_code;
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extern void __fentry__(void);
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static inline unsigned long ftrace_call_adjust(unsigned long addr)
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{
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/*
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* addr is the address of the mcount call instruction.
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* recordmcount does the necessary offset calculation.
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*/
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return addr;
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}
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#ifdef CONFIG_DYNAMIC_FTRACE
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struct dyn_arch_ftrace {
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/* No extra data needed for x86 */
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};
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int ftrace_int3_handler(struct pt_regs *regs);
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#define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR
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#endif /* CONFIG_DYNAMIC_FTRACE */
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_FUNCTION_TRACER */
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#ifndef __ASSEMBLY__
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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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/*
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* Compare the symbol name with the system call name. Skip the
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* "__x64_sys", "__ia32_sys" or simple "sys" prefix.
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*/
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return !strcmp(sym + 3, name + 3) ||
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(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
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(!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3));
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}
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#ifndef COMPILE_OFFSETS
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#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
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#include <linux/compat.h>
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/*
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* Because ia32 syscalls do not map to x86_64 syscall numbers
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* this screws up the trace output when tracing a ia32 task.
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* Instead of reporting bogus syscalls, just do not trace them.
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*
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* If the user really wants these, then they should use the
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* raw syscall tracepoints with filtering.
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*/
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#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
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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 in_32bit_syscall();
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}
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#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */
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#endif /* !COMPILE_OFFSETS */
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_X86_FTRACE_H */
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