From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
David Howells <dhowells@redhat.com>,
Greg Ungerer <gerg@linux-m68k.org>
Subject: [PATCH v4 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors
Date: Wed, 20 Jul 2016 15:22:39 -0400 [thread overview]
Message-ID: <1469042561-7360-11-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org>
This is needed on systems with a MMU. This also gets rid of the
strangest C code I've seen lateli i.e. an integer indexed with a
pointer value within square brackets. That really looked backwards.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
---
fs/binfmt_flat.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 92c1530a2c..aa7971ce6a 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -894,12 +894,19 @@ static int load_flat_binary(struct linux_binprm *bprm)
return res;
/* Update data segment pointers for all libraries */
- for (i = 0; i < MAX_SHARED_LIBS; i++)
- if (libinfo.lib_list[i].loaded)
- for (j = 0; j < MAX_SHARED_LIBS; j++)
- (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
- (libinfo.lib_list[j].loaded) ?
- libinfo.lib_list[j].start_data : UNLOADED_LIB;
+ for (i = 0; i < MAX_SHARED_LIBS; i++) {
+ if (!libinfo.lib_list[i].loaded)
+ continue;
+ for (j = 0; j < MAX_SHARED_LIBS; j++) {
+ unsigned long val = libinfo.lib_list[j].loaded ?
+ libinfo.lib_list[j].start_data : UNLOADED_LIB;
+ unsigned long __user *p = (unsigned long __user *)
+ libinfo.lib_list[i].start_data;
+ p -= j + 1;
+ if (put_user(val, p))
+ return -EFAULT;
+ }
+ }
install_exec_creds(bprm);
--
2.7.4
next prev parent reply other threads:[~2016-07-20 19:22 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 19:22 [PATCH v4 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 01/12] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 04/12] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 05/12] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 07/12] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 08/12] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
2016-07-20 19:22 ` Nicolas Pitre [this message]
2016-07-20 19:22 ` [PATCH v4 11/12] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-20 19:22 ` [PATCH v4 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
2016-07-21 6:58 ` [PATCH v4 00/12] allow BFLT executables on systems with a MMU Greg Ungerer
2016-07-21 14:48 ` Nicolas Pitre
2016-07-22 7:28 ` Greg Ungerer
2016-07-22 15:06 ` One Thousand Gnomes
2016-07-22 19:22 ` Russell King - ARM Linux
2016-07-22 19:45 ` Nicolas Pitre
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