[PATCH 19/24] ptrace: Allow compat to use the native siginfo

Andrew Pinski
2014-09-03T21:23:58Z

With ARM64 ILP32 ABI, we want to use the non-compat
siginfo as we want to simplify signal handling for this new ABI.
This patch just adds a new define COMPAT_USE_NATIVE_SIGINFO and
if it is true then read/write in the compat case as it was the
non-compat case.

Signed-off-by: Andrew Pinski <apinski@cavium.com>
---
include/linux/compat.h | 4 ++++
kernel/ptrace.c | 25 ++++++++++++++++++-------
2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index e649426..2d8c535 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -24,6 +24,10 @@
#define COMPAT_USE_64BIT_TIME 0
#endif

+#ifndef COMPAT_USE_NATIVE_SIGINFO
+#define COMPAT_USE_NATIVE_SIGINFO 0
+#endif
+
#ifndef __SC_DELOUSE
#define __SC_DELOUSE(t,v) ((t)(unsigned long)(v))
#endif
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 54e7522..40ae023 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -657,7 +657,7 @@ static int ptrace_peek_siginfo(struct task_struct *child,
break;

#ifdef CONFIG_COMPAT
- if (unlikely(is_compat_task())) {
+ if (unlikely(is_compat_task() && !COMPAT_USE_NATIVE_SIGINFO)) {
compat_siginfo_t __user *uinfo = compat_ptr(data);

if (copy_siginfo_to_user32(uinfo, &info) ||
@@ -1126,16 +1126,27 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request,

case PTRACE_GETSIGINFO:
ret = ptrace_getsiginfo(child, &siginfo);
- if (!ret)
- ret = copy_siginfo_to_user32(
- (struct compat_siginfo __user *) datap,
- &siginfo);
+ if (!ret) {
+ if (COMPAT_USE_NATIVE_SIGINFO)
+ ret = copy_siginfo_to_user(
+ (struct siginfo __user *) datap,
+ &siginfo);
+ else
+ ret = copy_siginfo_to_user32(
+ (struct compat_siginfo __user *) datap,
+ &siginfo);
+ }
break;

case PTRACE_SETSIGINFO:
memset(&siginfo, 0, sizeof siginfo);
- if (copy_siginfo_from_user32(
- &siginfo, (struct compat_siginfo __user *) datap))
+ if (COMPAT_USE_NATIVE_SIGINFO)
+ ret = copy_from_user(&siginfo, datap, sizeof(siginfo));
+ else
+ ret = copy_siginfo_from_user32(
+ &siginfo,
+ (struct compat_siginfo __user *) datap);
+ if (ret)
ret = -EFAULT;
else
ret = ptrace_setsiginfo(child, &siginfo);
--
1.7.2.5