[PATCH] fixup! signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32

Arnd Bergmann
2020-04-28T20:13:01Z

I think I found a way to improve the x32 handling:

This is a simplification over Christoph's "[PATCH 2/7] signal: factor
copy_siginfo_to_external32 from copy_siginfo_to_user32", reducing the
x32 specifics in the common code to a single #ifdef/#endif check, in
order to keep it more readable for everyone else.

Christoph, if you like it, please fold into your patch.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/x86/include/asm/compat.h | 10 ++++++++++
arch/x86/kernel/signal.c | 23 +++++++++++++++++++++++
kernel/signal.c | 15 ++-------------
3 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 52e9f3480f69..9341ea3da757 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -214,7 +214,17 @@ static inline bool in_compat_syscall(void)
#endif

struct compat_siginfo;
+#ifdef CONFIG_X86_X32_ABI
int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
const kernel_siginfo_t *from, bool x32_ABI);
+#else
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const kernel_siginfo_t *from);
+static inline int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const kernel_siginfo_t *from, bool x32_ABI)
+{
+ return copy_siginfo_to_user32(to, from);
+}
+#endif

#endif /* _ASM_X86_COMPAT_H */
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 83b74fb38c8f..0e166571d28b 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -511,6 +511,29 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
}
#endif /* CONFIG_X86_32 */

+#ifdef CONFIG_X86_X32_ABI
+int copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from)
+{
+ return __copy_siginfo_to_user32(to, from, in_x32_syscall());
+}
+
+int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
+ const struct kernel_siginfo *from, bool x32_ABI)
+{
+ struct compat_siginfo new;
+
+ copy_siginfo_to_external32(&new, from);
+ if (x32_ABI && from->si_signo == SIGCHLD) {
+ new._sifields._sigchld_x32._utime = from->si_utime;
+ new._sifields._sigchld_x32._stime = from->si_stime;
+ }
+ if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
+ return -EFAULT;
+ return 0;
+}
+#endif
+
static int x32_setup_rt_frame(struct ksignal *ksig,
compat_sigset_t *set,
struct pt_regs *regs)
diff --git a/kernel/signal.c b/kernel/signal.c
index 1a81602050b4..935facca4860 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3318,29 +3318,18 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
}
}

+#ifndef CONFIG_X86_X32_ABI
int copy_siginfo_to_user32(struct compat_siginfo __user *to,
const struct kernel_siginfo *from)
-#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
-{
- return __copy_siginfo_to_user32(to, from, in_x32_syscall());
-}
-int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
- const struct kernel_siginfo *from, bool x32_ABI)
-#endif
{
struct compat_siginfo new;

copy_siginfo_to_external32(&new, from);
-#ifdef CONFIG_X86_X32_ABI
- if (x32_ABI && from->si_signo == SIGCHLD) {
- new._sifields._sigchld_x32._utime = from->si_utime;
- new._sifields._sigchld_x32._stime = from->si_stime;
- }
-#endif
if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
return -EFAULT;
return 0;
}
+#endif

static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
const struct compat_siginfo *from)
--
2.26.0