[PATCH v6 12/19] ptrace: Allow compat to use the native siginfo

From: Yury Norov
Date: Tue Nov 17 2015 - 16:20:47 EST


From: Andrew Pinski <apinski@xxxxxxxxxx>

Set COMPAT_USE_NATIVE_SIGINFO to be true for non AARCH32 tasks.

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.

Reviewed-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Christoph Muellner <christoph.muellner@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Philipp Tomsich <philipp.tomsich@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Pinski <Andrew.Pinski@xxxxxxxxxxxxxxxxxx>
---
include/linux/compat.h | 4 ++++
kernel/ptrace.c | 24 +++++++++++++++++-------
2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index a76c917..0a25d90 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 787320d..04799aa 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -652,7 +652,7 @@ 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) ||
@@ -1140,16 +1140,26 @@ 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);
--
2.1.4

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