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authorPeter Zijlstra <peterz@infradead.org>2019-05-08 00:25:54 +0300
committerIngo Molnar <mingo@kernel.org>2019-06-25 11:23:47 +0300
commit3c88c692c28746473791276f8b42d2c989d6cbe6 (patch)
tree51cb03ef4cbb611f42ea43c8737be894991b656b /arch/x86/include/asm/ptrace.h
parentea1ed38dba64b64a245ab8ca1406269d17b99485 (diff)
downloadlinux-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.h17
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))