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authorEric W. Biederman <ebiederm@xmission.com>2020-05-05 12:12:54 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2020-05-05 16:46:10 -0400
commitfa4751f454e6b51ef93babfd8b6c8b43a65c9db2 (patch)
tree0333e3b9b52243632a204fc5ffafa63e8329d5a1
parentc3b3f52476412a3899f2c65b220075aceb18dd2c (diff)
binfmt_elf: remove the set_fs in fill_siginfo_note
The code in binfmt_elf.c is differnt from the rest of the code that processes siginfo, as it sends siginfo from a kernel buffer to a file rather than from kernel memory to userspace buffers. To remove it's use of set_fs the code needs some different siginfo helpers. Add the helper copy_siginfo_to_external to copy from the kernel's internal siginfo layout to a buffer in the siginfo layout that userspace expects. Modify fill_siginfo_note to use copy_siginfo_to_external instead of set_fs and copy_siginfo_to_user. Update compat_binfmt_elf.c to use the previously added copy_siginfo_to_external32 to handle the compat case. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/binfmt_elf.c5
-rw-r--r--fs/compat_binfmt_elf.c2
-rw-r--r--include/linux/signal.h8
3 files changed, 10 insertions, 5 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 13f25e241ac4..a1f57e20c3cf 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1556,10 +1556,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
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);
+ copy_siginfo_to_external(csigdata, siginfo);
fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}
diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c
index aaad4ca1217e..fa0e24e1b726 100644
--- a/fs/compat_binfmt_elf.c
+++ b/fs/compat_binfmt_elf.c
@@ -39,7 +39,7 @@
*/
#define user_long_t compat_long_t
#define user_siginfo_t compat_siginfo_t
-#define copy_siginfo_to_user copy_siginfo_to_user32
+#define copy_siginfo_to_external copy_siginfo_to_external32
/*
* The machine-dependent core note format types are defined in elfcore-compat.h,
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 05bacd2ab135..6bb1a3f0258c 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -24,6 +24,14 @@ static inline void clear_siginfo(kernel_siginfo_t *info)
#define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo))
+static inline void copy_siginfo_to_external(siginfo_t *to,
+ const kernel_siginfo_t *from)
+{
+ memcpy(to, from, sizeof(*from));
+ memset(((char *)to) + sizeof(struct kernel_siginfo), 0,
+ SI_EXPANSION_SIZE);
+}
+
int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from);
int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);