[patch 6/8] compat ptrace cleanup

From: Martin Schwidefsky
Date: Tue May 06 2008 - 12:05:40 EST


From: Roland McGrath <roland@xxxxxxxxxx>

This removes redundant arch code for generic ptrace requests
already handled by ptrace_request and compat_ptrace_request.
It simplifies things to just have the standard entry points,
and use the generic compat_sys_ptrace.

Signed-off-by: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

arch/s390/kernel/compat_wrapper.S | 2
arch/s390/kernel/ptrace.c | 100 ++------------------------------------
include/asm-s390/ptrace.h | 2
3 files changed, 9 insertions(+), 95 deletions(-)

Index: quilt-2.6/arch/s390/kernel/compat_wrapper.S
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/compat_wrapper.S
+++ quilt-2.6/arch/s390/kernel/compat_wrapper.S
@@ -121,7 +121,7 @@ sys32_ptrace_wrapper:
lgfr %r3,%r3 # long
llgtr %r4,%r4 # long
llgfr %r5,%r5 # long
- jg sys_ptrace # branch to system call
+ jg compat_sys_ptrace # branch to system call

.globl sys32_alarm_wrapper
sys32_alarm_wrapper:
Index: quilt-2.6/arch/s390/kernel/ptrace.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/ptrace.c
+++ quilt-2.6/arch/s390/kernel/ptrace.c
@@ -292,8 +292,7 @@ poke_user(struct task_struct *child, add
return 0;
}

-static int
-do_ptrace_normal(struct task_struct *child, long request, long addr, long data)
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
ptrace_area parea;
int copied, ret;
@@ -529,35 +528,19 @@ poke_user_emu31(struct task_struct *chil
return 0;
}

-static int
-do_ptrace_emu31(struct task_struct *child, long request, long addr, long data)
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+ compat_ulong_t caddr, compat_ulong_t cdata)
{
- unsigned int tmp; /* 4 bytes !! */
+ unsigned long addr = caddr;
+ unsigned long data = cdata;
ptrace_area_emu31 parea;
int copied, ret;

switch (request) {
- case PTRACE_PEEKTEXT:
- case PTRACE_PEEKDATA:
- /* read word at location addr. */
- copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
- if (copied != sizeof(tmp))
- return -EIO;
- return put_user(tmp, (unsigned int __force __user *) data);
-
case PTRACE_PEEKUSR:
/* read the word at location addr in the USER area. */
return peek_user_emu31(child, addr, data);

- case PTRACE_POKETEXT:
- case PTRACE_POKEDATA:
- /* write the word at location addr. */
- tmp = data;
- copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 1);
- if (copied != sizeof(tmp))
- return -EIO;
- return 0;
-
case PTRACE_POKEUSR:
/* write the word at location addr in the USER area */
return poke_user_emu31(child, addr, data);
@@ -587,82 +570,11 @@ do_ptrace_emu31(struct task_struct *chil
copied += sizeof(unsigned int);
}
return 0;
- case PTRACE_GETEVENTMSG:
- return put_user((__u32) child->ptrace_message,
- (unsigned int __force __user *) data);
- case PTRACE_GETSIGINFO:
- if (child->last_siginfo == NULL)
- return -EINVAL;
- return copy_siginfo_to_user32((compat_siginfo_t
- __force __user *) data,
- child->last_siginfo);
- case PTRACE_SETSIGINFO:
- if (child->last_siginfo == NULL)
- return -EINVAL;
- return copy_siginfo_from_user32(child->last_siginfo,
- (compat_siginfo_t
- __force __user *) data);
}
- return ptrace_request(child, request, addr, data);
+ return compat_ptrace_request(child, request, addr, data);
}
#endif

-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
- switch (request) {
- case PTRACE_SYSCALL:
- /* continue and stop at next (return from) syscall */
- case PTRACE_CONT:
- /* restart after signal. */
- if (!valid_signal(data))
- return -EIO;
- if (request == PTRACE_SYSCALL)
- set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- else
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- /* make sure the single step bit is not set. */
- user_disable_single_step(child);
- wake_up_process(child);
- return 0;
-
- case PTRACE_KILL:
- /*
- * make the child exit. Best I can do is send it a sigkill.
- * perhaps it should be put in the status that it wants to
- * exit.
- */
- if (child->exit_state == EXIT_ZOMBIE) /* already dead */
- return 0;
- child->exit_code = SIGKILL;
- /* make sure the single step bit is not set. */
- user_disable_single_step(child);
- wake_up_process(child);
- return 0;
-
- case PTRACE_SINGLESTEP:
- /* set the trap flag. */
- if (!valid_signal(data))
- return -EIO;
- clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->exit_code = data;
- user_enable_single_step(child);
- /* give it a chance to run. */
- wake_up_process(child);
- return 0;
-
- /* Do requests that differ for 31/64 bit */
- default:
-#ifdef CONFIG_COMPAT
- if (test_thread_flag(TIF_31BIT))
- return do_ptrace_emu31(child, request, addr, data);
-#endif
- return do_ptrace_normal(child, request, addr, data);
- }
- /* Not reached. */
- return -EIO;
-}
-
asmlinkage void
syscall_trace(struct pt_regs *regs, int entryexit)
{
Index: quilt-2.6/include/asm-s390/ptrace.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/ptrace.h
+++ quilt-2.6/include/asm-s390/ptrace.h
@@ -471,6 +471,8 @@ struct task_struct;
extern void user_enable_single_step(struct task_struct *);
extern void user_disable_single_step(struct task_struct *);

+#define __ARCH_WANT_COMPAT_SYS_PTRACE
+
#define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
#define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN)
#define regs_return_value(regs)((regs)->gprs[2])

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

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