From: Christoph Hellwig <hch@lst.de> To: Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org>, Jeremy Kerr <jk@ozlabs.org>, Arnd Bergmann <arnd@arndb.de>, Oleg Nesterov <oleg@redhat.com>, "Eric W . Biederman" <ebiederm@xmission.com>, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/7] binfmt_elf: remove the set_fs in fill_siginfo_note Date: Tue, 5 May 2020 12:12:54 +0200 [thread overview] Message-ID: <20200505101256.3121270-6-hch@lst.de> (raw) In-Reply-To: <20200505101256.3121270-1-hch@lst.de> From: "Eric W. Biederman" <ebiederm@xmission.com> 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> --- fs/binfmt_elf.c | 5 +---- fs/compat_binfmt_elf.c | 2 +- include/linux/signal.h | 8 ++++++++ 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 13f25e241ac46..a1f57e20c3cf2 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 aaad4ca1217ef..fa0e24e1b7267 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 05bacd2ab1350..6bb1a3f0258c2 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); -- 2.26.2
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de> To: Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de>, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, Oleg Nesterov <oleg@redhat.com>, linux-kernel@vger.kernel.org, "Eric W . Biederman" <ebiederm@xmission.com>, linux-fsdevel@vger.kernel.org, Linus Torvalds <torvalds@linux-foundation.org>, Jeremy Kerr <jk@ozlabs.org> Subject: [PATCH 5/7] binfmt_elf: remove the set_fs in fill_siginfo_note Date: Tue, 5 May 2020 12:12:54 +0200 [thread overview] Message-ID: <20200505101256.3121270-6-hch@lst.de> (raw) In-Reply-To: <20200505101256.3121270-1-hch@lst.de> From: "Eric W. Biederman" <ebiederm@xmission.com> 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> --- fs/binfmt_elf.c | 5 +---- fs/compat_binfmt_elf.c | 2 +- include/linux/signal.h | 8 ++++++++ 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 13f25e241ac46..a1f57e20c3cf2 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 aaad4ca1217ef..fa0e24e1b7267 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 05bacd2ab1350..6bb1a3f0258c2 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); -- 2.26.2
next prev parent reply other threads:[~2020-05-05 10:13 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-05 10:12 remove set_fs calls from the coredump code v6 Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` [PATCH 1/7] powerpc/spufs: fix copy_to_user while atomic Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` [PATCH 2/7] powerpc/spufs: stop using access_ok Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` [PATCH 3/7] powerpc/spufs: simplify spufs core dumping Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` [PATCH 4/7] signal: refactor copy_siginfo_to_user32 Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig [this message] 2020-05-05 10:12 ` [PATCH 5/7] binfmt_elf: remove the set_fs in fill_siginfo_note Christoph Hellwig 2020-05-05 10:12 ` [PATCH 6/7] binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 10:12 ` [PATCH 7/7] binfmt_elf_fdpic: remove the set_fs(KERNEL_DS) in elf_fdpic_core_dump Christoph Hellwig 2020-05-05 10:12 ` Christoph Hellwig 2020-05-05 16:52 ` remove set_fs calls from the coredump code v6 Linus Torvalds 2020-05-05 16:52 ` Linus Torvalds 2020-05-05 20:28 ` Eric W. Biederman 2020-05-05 20:28 ` Eric W. Biederman 2020-05-06 6:31 ` Christoph Hellwig 2020-05-06 6:31 ` Christoph Hellwig 2020-05-06 15:44 ` Eric W. Biederman 2020-05-06 15:44 ` Eric W. Biederman 2020-05-05 20:34 ` Al Viro 2020-05-05 20:34 ` Al Viro 2020-05-05 20:42 ` Christoph Hellwig 2020-05-05 20:42 ` Christoph Hellwig 2020-05-05 20:47 ` Al Viro 2020-05-05 20:47 ` Al Viro
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