Re: nios2: is the ptrace ABI correct?
From: Chung-Lin Tang
Date: Mon Mar 09 2015 - 13:02:57 EST
On 2015/3/10 12:54 AM, Chung-Lin Tang wrote:
> It appears that some of the ways nios2 has organized the
> ucontext/pt_regs/etc. are remnants of the pre-generic code, some
> basically because the port was based off m68k.
>
> I've re-organized the headers a bit: nios2/include/asm/ucontext.h is
> deleted, and re-definition of struct sigcontext now allows use of
> uapi/asm-generic/ucontext.h directly. Note that the reorg, despite
> effectively renaming some fields, is still binary compatible. I'll
> probably update the corresponding glibc definitions later.
>
> struct pt_regs is now not exported, and all exported register sets are
> now supposed to follow the 49 register set defined as in GDB now.
>
> Tobias, Ley Foon, how do you think this looks?
Sorry, accidentally attached unrelated GCC patch instead, this one's the
correct one.
Chung-Lin
diff --git a/arch/nios2/include/asm/ptrace.h b/arch/nios2/include/asm/ptrace.h
index 20fb1cf..6424621 100644
--- a/arch/nios2/include/asm/ptrace.h
+++ b/arch/nios2/include/asm/ptrace.h
@@ -15,7 +15,54 @@
#include <uapi/asm/ptrace.h>
+/* This struct defines the way the registers are stored on the
+ stack during a system call. */
+
#ifndef __ASSEMBLY__
+struct pt_regs {
+ unsigned long r8; /* r8-r15 Caller-saved GP registers */
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+ unsigned long r15;
+ unsigned long r1; /* Assembler temporary */
+ unsigned long r2; /* Retval LS 32bits */
+ unsigned long r3; /* Retval MS 32bits */
+ unsigned long r4; /* r4-r7 Register arguments */
+ unsigned long r5;
+ unsigned long r6;
+ unsigned long r7;
+ unsigned long orig_r2; /* Copy of r2 ?? */
+ unsigned long ra; /* Return address */
+ unsigned long fp; /* Frame pointer */
+ unsigned long sp; /* Stack pointer */
+ unsigned long gp; /* Global pointer */
+ unsigned long estatus;
+ unsigned long ea; /* Exception return address (pc) */
+ unsigned long orig_r7;
+};
+
+/*
+ * This is the extended stack used by signal handlers and the context
+ * switcher: it's pushed after the normal "struct pt_regs".
+ */
+struct switch_stack {
+ unsigned long r16; /* r16-r23 Callee-saved GP registers */
+ unsigned long r17;
+ unsigned long r18;
+ unsigned long r19;
+ unsigned long r20;
+ unsigned long r21;
+ unsigned long r22;
+ unsigned long r23;
+ unsigned long fp;
+ unsigned long gp;
+ unsigned long ra;
+};
+
#define user_mode(regs) (((regs)->estatus & ESTATUS_EU))
#define instruction_pointer(regs) ((regs)->ra)
diff --git a/arch/nios2/include/asm/ucontext.h b/arch/nios2/include/asm/ucontext.h
deleted file mode 100644
index 2c87614..0000000
--- a/arch/nios2/include/asm/ucontext.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx>
- * Copyright (C) 2004 Microtronix Datacom Ltd
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-
-#ifndef _ASM_NIOS2_UCONTEXT_H
-#define _ASM_NIOS2_UCONTEXT_H
-
-typedef int greg_t;
-#define NGREG 32
-typedef greg_t gregset_t[NGREG];
-
-struct mcontext {
- int version;
- gregset_t gregs;
-};
-
-#define MCONTEXT_VERSION 2
-
-struct ucontext {
- unsigned long uc_flags;
- struct ucontext *uc_link;
- stack_t uc_stack;
- struct mcontext uc_mcontext;
- sigset_t uc_sigmask; /* mask last for extensibility */
-};
-
-#endif
diff --git a/arch/nios2/include/uapi/asm/Kbuild b/arch/nios2/include/uapi/asm/Kbuild
index 4f07ca3f8..37613119 100644
--- a/arch/nios2/include/uapi/asm/Kbuild
+++ b/arch/nios2/include/uapi/asm/Kbuild
@@ -2,3 +2,5 @@ include include/uapi/asm-generic/Kbuild.asm
header-y += elf.h
header-y += ucontext.h
+
+generic-y += ucontext.h
diff --git a/arch/nios2/include/uapi/asm/elf.h b/arch/nios2/include/uapi/asm/elf.h
index a5b91ae..6f06d3b 100644
--- a/arch/nios2/include/uapi/asm/elf.h
+++ b/arch/nios2/include/uapi/asm/elf.h
@@ -50,9 +50,7 @@
typedef unsigned long elf_greg_t;
-#define ELF_NGREG \
- ((sizeof(struct pt_regs) + sizeof(struct switch_stack)) / \
- sizeof(elf_greg_t))
+#define ELF_NGREG 49
typedef elf_greg_t elf_gregset_t[ELF_NGREG];
typedef unsigned long elf_fpregset_t;
diff --git a/arch/nios2/include/uapi/asm/ptrace.h b/arch/nios2/include/uapi/asm/ptrace.h
index e83a7c9..71a3305 100644
--- a/arch/nios2/include/uapi/asm/ptrace.h
+++ b/arch/nios2/include/uapi/asm/ptrace.h
@@ -67,53 +67,9 @@
#define NUM_PTRACE_REG (PTR_TLBMISC + 1)
-/* this struct defines the way the registers are stored on the
- stack during a system call.
-
- There is a fake_regs in setup.c that has to match pt_regs.*/
-
-struct pt_regs {
- unsigned long r8; /* r8-r15 Caller-saved GP registers */
- unsigned long r9;
- unsigned long r10;
- unsigned long r11;
- unsigned long r12;
- unsigned long r13;
- unsigned long r14;
- unsigned long r15;
- unsigned long r1; /* Assembler temporary */
- unsigned long r2; /* Retval LS 32bits */
- unsigned long r3; /* Retval MS 32bits */
- unsigned long r4; /* r4-r7 Register arguments */
- unsigned long r5;
- unsigned long r6;
- unsigned long r7;
- unsigned long orig_r2; /* Copy of r2 ?? */
- unsigned long ra; /* Return address */
- unsigned long fp; /* Frame pointer */
- unsigned long sp; /* Stack pointer */
- unsigned long gp; /* Global pointer */
- unsigned long estatus;
- unsigned long ea; /* Exception return address (pc) */
- unsigned long orig_r7;
-};
-
-/*
- * This is the extended stack used by signal handlers and the context
- * switcher: it's pushed after the normal "struct pt_regs".
- */
-struct switch_stack {
- unsigned long r16; /* r16-r23 Callee-saved GP registers */
- unsigned long r17;
- unsigned long r18;
- unsigned long r19;
- unsigned long r20;
- unsigned long r21;
- unsigned long r22;
- unsigned long r23;
- unsigned long fp;
- unsigned long gp;
- unsigned long ra;
+/* User structures for general purpose registers. */
+struct user_pt_regs {
+ __u32 regs[49];
};
#endif /* __ASSEMBLY__ */
diff --git a/arch/nios2/include/uapi/asm/sigcontext.h b/arch/nios2/include/uapi/asm/sigcontext.h
index 7b8bb41..b67944a 100644
--- a/arch/nios2/include/uapi/asm/sigcontext.h
+++ b/arch/nios2/include/uapi/asm/sigcontext.h
@@ -15,14 +15,16 @@
* details.
*/
-#ifndef _ASM_NIOS2_SIGCONTEXT_H
-#define _ASM_NIOS2_SIGCONTEXT_H
+#ifndef _UAPI__ASM_SIGCONTEXT_H
+#define _UAPI__ASM_SIGCONTEXT_H
-#include <asm/ptrace.h>
+#include <linux/types.h>
+
+#define MCONTEXT_VERSION 2
struct sigcontext {
- struct pt_regs regs;
- unsigned long sc_mask; /* old sigmask */
+ int version;
+ unsigned long gregs[32];
};
#endif
diff --git a/arch/nios2/kernel/signal.c b/arch/nios2/kernel/signal.c
index 2d0ea25..dda41e4 100644
--- a/arch/nios2/kernel/signal.c
+++ b/arch/nios2/kernel/signal.c
@@ -39,7 +39,7 @@ static inline int rt_restore_ucontext(struct pt_regs *regs,
struct ucontext *uc, int *pr2)
{
int temp;
- greg_t *gregs = uc->uc_mcontext.gregs;
+ unsigned long *gregs = uc->uc_mcontext.gregs;
int err;
/* Always make any pending restarted system calls return -EINTR */
@@ -127,7 +127,7 @@ badframe:
static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
{
struct switch_stack *sw = (struct switch_stack *)regs - 1;
- greg_t *gregs = uc->uc_mcontext.gregs;
+ unsigned long *gregs = uc->uc_mcontext.gregs;
int err = 0;
err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);