[PATCH 4/8] binfmt_elf: open code copy_siginfo_to_user to kernelspace buffer

[Christoph Hellwig]

Instead of messing with the address limit just open code the trivial
memcpy + memset logic for the native version, and a call to
to_compat_siginfo for the compat version.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 fs/binfmt_elf.c        | 9 +++++----
 fs/compat_binfmt_elf.c | 6 +++++-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 13f25e241ac4..607c5a5f855e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1553,15 +1553,16 @@ static void fill_auxv_note(struct memelfnote *note, 
struct mm_struct *mm)
        fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
 }
 
+#ifndef fill_siginfo_note
 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t 
*csigdata,
                const kernel_siginfo_t *siginfo)
 {
-       mm_segment_t old_fs = get_fs();
-       set_fs(KERNEL_DS);
-       copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
-       set_fs(old_fs);
+       memcpy(csigdata, siginfo, sizeof(struct kernel_siginfo));
+       memset((char *)csigdata + sizeof(struct kernel_siginfo), 0,
+               SI_EXPANSION_SIZE);
        fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
 }
+#endif
 
 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
 /*
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index aaad4ca1217e..ab84e095618b 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -39,7 +39,11 @@
  */
 #define user_long_t            compat_long_t
 #define user_siginfo_t         compat_siginfo_t
-#define copy_siginfo_to_user   copy_siginfo_to_user32
+#define fill_siginfo_note(note, csigdata, siginfo)             \
+do {                                                                   \
+       to_compat_siginfo(csigdata, siginfo, compat_siginfo_flags());   \
+       fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); \
+} while (0)
 
 /*
  * The machine-dependent core note format types are defined in 
elfcore-compat.h,
-- 
2.25.1