[patch 21/33] Add compat handler for PTRACE_GETSIGINFO

Greg KH
2008-08-04T20:28:41Z

[-- Attachment #1: add-compat-handler-for-ptrace_getsiginfo.patch --]
[-- Type: text/plain, Size: 2436 bytes --]

2.6.25-stable review patch. If anyone has any objections, please let us
know.

------------------

From: Andreas Schwab <schwab@suse.de>

commit e4cc58944c1e2ce41e3079d4eb60c95e7ce04b2b upstream

Current versions of gdb require a working implementation of
PTRACE_GETSIGINFO for proper watchpoint support. Since struct siginfo
contains pointers it must be converted when passed to a 32-bit debugger.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/powerpc/kernel/ppc32.h | 2 ++
arch/powerpc/kernel/ptrace32.c | 27 +++++++++++++++++++++++++++
2 files changed, 29 insertions(+)

--- a/arch/powerpc/kernel/ppc32.h
+++ b/arch/powerpc/kernel/ppc32.h
@@ -135,4 +135,6 @@ struct ucontext32 {
struct mcontext32 uc_mcontext;
};

+extern int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s);
+
#endif /* _PPC64_PPC32_H */
--- a/arch/powerpc/kernel/ptrace32.c
+++ b/arch/powerpc/kernel/ptrace32.c
@@ -29,12 +29,15 @@
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/compat.h>
+#include <linux/elf.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>

+#include "ppc32.h"
+
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
@@ -64,6 +67,27 @@ static long compat_ptrace_old(struct tas
return -EPERM;
}

+static int compat_ptrace_getsiginfo(struct task_struct *child, compat_siginfo_t __user *data)
+{
+ siginfo_t lastinfo;
+ int error = -ESRCH;
+
+ read_lock(&tasklist_lock);
+ if (likely(child->sighand != NULL)) {
+ error = -EINVAL;
+ spin_lock_irq(&child->sighand->siglock);
+ if (likely(child->last_siginfo != NULL)) {
+ lastinfo = *child->last_siginfo;
+ error = 0;
+ }
+ spin_unlock_irq(&child->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+ if (!error)
+ return copy_siginfo_to_user32(data, &lastinfo);
+ return error;
+}
+
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t caddr, compat_ulong_t cdata)
{
@@ -282,6 +306,9 @@ long compat_arch_ptrace(struct task_stru
0, PT_REGS_COUNT * sizeof(compat_long_t),
compat_ptr(data));

+ case PTRACE_GETSIGINFO:
+ return compat_ptrace_getsiginfo(child, compat_ptr(data));
+
case PTRACE_GETFPREGS:
case PTRACE_SETFPREGS:
case PTRACE_GETVRREGS:

--