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| author | Peter Zijlstra <peterz@infradead.org> | 2019-05-08 00:25:54 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-06-25 11:23:47 +0300 |
| commit | 3c88c692c28746473791276f8b42d2c989d6cbe6 (patch) | |
| tree | 51cb03ef4cbb611f42ea43c8737be894991b656b /arch/x86/include/asm/ptrace.h | |
| parent | ea1ed38dba64b64a245ab8ca1406269d17b99485 (diff) | |
| download | linux-3c88c692c28746473791276f8b42d2c989d6cbe6.tar.xz | |
x86/stackframe/32: Provide consistent pt_regs
Currently pt_regs on x86_32 has an oddity in that kernel regs
(!user_mode(regs)) are short two entries (esp/ss). This means that any
code trying to use them (typically: regs->sp) needs to jump through
some unfortunate hoops.
Change the entry code to fix this up and create a full pt_regs frame.
This then simplifies various trampolines in ftrace and kprobes, the
stack unwinder, ptrace, kdump and kgdb.
Much thanks to Josh for help with the cleanups!
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 17 |
1 files changed, 2 insertions, 15 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 8a7fc0cca2d1..3703c91f441e 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -166,14 +166,10 @@ static inline bool user_64bit_mode(struct pt_regs *regs) #define compat_user_stack_pointer() current_pt_regs()->sp #endif -#ifdef CONFIG_X86_32 -extern unsigned long kernel_stack_pointer(struct pt_regs *regs); -#else static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) { return regs->sp; } -#endif #define GET_IP(regs) ((regs)->ip) #define GET_FP(regs) ((regs)->bp) @@ -201,14 +197,6 @@ static inline unsigned long regs_get_register(struct pt_regs *regs, if (unlikely(offset > MAX_REG_OFFSET)) return 0; #ifdef CONFIG_X86_32 - /* - * Traps from the kernel do not save sp and ss. - * Use the helper function to retrieve sp. - */ - if (offset == offsetof(struct pt_regs, sp) && - regs->cs == __KERNEL_CS) - return kernel_stack_pointer(regs); - /* The selector fields are 16-bit. */ if (offset == offsetof(struct pt_regs, cs) || offset == offsetof(struct pt_regs, ss) || @@ -234,8 +222,7 @@ static inline unsigned long regs_get_register(struct pt_regs *regs, static inline int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) { - return ((addr & ~(THREAD_SIZE - 1)) == - (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); + return ((addr & ~(THREAD_SIZE - 1)) == (regs->sp & ~(THREAD_SIZE - 1))); } /** @@ -249,7 +236,7 @@ static inline int regs_within_kernel_stack(struct pt_regs *regs, */ static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n) { - unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); + unsigned long *addr = (unsigned long *)regs->sp; addr += n; if (regs_within_kernel_stack(regs, (unsigned long)addr)) |