x86/asm/entry/64: Fix comments

- Misleading and slightly incorrect comments in "struct pt_regs" are
   fixed (four instances).

 - Fix incorrect comment atop EMPTY_FRAME macro.

 - Explain in more detail what we do with stack layout during hw interrupt.

 - Correct comments about "partial stack frame" which are no longer
   true.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-3-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/e1f4429c491fe6ceeddb879dea2786e0f8920f9c.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Denys Vlasenko
2015-02-26 14:40:28 -08:00
committed by Ingo Molnar
parent 76f5df43ca
commit e90e147cbc
4 changed files with 43 additions and 16 deletions

View File

@@ -25,13 +25,17 @@
#else /* __i386__ */
#if defined(__ASSEMBLY__) || defined(__FRAME_OFFSETS)
/*
* C ABI says these regs are callee-preserved. They aren't saved on kernel entry
* unless syscall needs a complete, fully filled "struct pt_regs".
*/
#define R15 0
#define R14 8
#define R13 16
#define R12 24
#define RBP 32
#define RBX 40
/* arguments: interrupts/non tracing syscalls only save up to here*/
/* These regs are callee-clobbered. Always saved on kernel entry. */
#define R11 48
#define R10 56
#define R9 64
@@ -41,9 +45,12 @@
#define RDX 96
#define RSI 104
#define RDI 112
#define ORIG_RAX 120 /* = ERROR */
/* end of arguments */
/* cpu exception frame or undefined in case of fast syscall. */
/*
* On syscall entry, this is syscall#. On CPU exception, this is error code.
* On hw interrupt, it's IRQ number:
*/
#define ORIG_RAX 120
/* Return frame for iretq */
#define RIP 128
#define CS 136
#define EFLAGS 144

View File

@@ -41,13 +41,17 @@ struct pt_regs {
#ifndef __KERNEL__
struct pt_regs {
/*
* C ABI says these regs are callee-preserved. They aren't saved on kernel entry
* unless syscall needs a complete, fully filled "struct pt_regs".
*/
unsigned long r15;
unsigned long r14;
unsigned long r13;
unsigned long r12;
unsigned long rbp;
unsigned long rbx;
/* arguments: non interrupts/non tracing syscalls only save up to here*/
/* These regs are callee-clobbered. Always saved on kernel entry. */
unsigned long r11;
unsigned long r10;
unsigned long r9;
@@ -57,9 +61,12 @@ struct pt_regs {
unsigned long rdx;
unsigned long rsi;
unsigned long rdi;
/*
* On syscall entry, this is syscall#. On CPU exception, this is error code.
* On hw interrupt, it's IRQ number:
*/
unsigned long orig_rax;
/* end of arguments */
/* cpu exception frame or undefined */
/* Return frame for iretq */
unsigned long rip;
unsigned long cs;
unsigned long eflags;