summaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm/ptrace.h
diff options
context:
space:
mode:
authorDenys Vlasenko <dvlasenk@redhat.com>2015-02-26 23:40:28 +0100
committerIngo Molnar <mingo@kernel.org>2015-03-04 22:50:49 +0100
commite90e147cbc0cbc8dcf48000e15190badf75250f4 (patch)
tree9f581213586bd2c4ae4e07f5c3e16204ceb3deda /arch/x86/include/asm/ptrace.h
parentx86/asm/entry/64: Always allocate a complete "struct pt_regs" on the kernel s... (diff)
downloadlinux-e90e147cbc0cbc8dcf48000e15190badf75250f4.tar.xz
linux-e90e147cbc0cbc8dcf48000e15190badf75250f4.zip
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>
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
-rw-r--r--arch/x86/include/asm/ptrace.h13
1 files changed, 10 insertions, 3 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 86fc2bb82287..4077d963a1a0 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -31,13 +31,17 @@ struct pt_regs {
#else /* __i386__ */
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 bp;
unsigned long bx;
-/* 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;
@@ -47,9 +51,12 @@ struct pt_regs {
unsigned long dx;
unsigned long si;
unsigned long di;
+/*
+ * On syscall entry, this is syscall#. On CPU exception, this is error code.
+ * On hw interrupt, it's IRQ number:
+ */
unsigned long orig_ax;
-/* end of arguments */
-/* cpu exception frame or undefined */
+/* Return frame for iretq */
unsigned long ip;
unsigned long cs;
unsigned long flags;