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 v3 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors
Date: Wed, 20 Jul 2016 00:20:22 -0400 [thread overview]
Message-ID: <1468988424-32671-11-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1468988424-32671-1-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 0d89830f76..fef94aaa36 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -897,12 +897,19 @@ 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 4:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 01/12] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
2016-07-20 4:30 ` Joe Perches
2016-07-20 5:05 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 04/12] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 05/12] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 07/12] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 08/12] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
2016-07-20 7:15 ` Greg Ungerer
2016-07-20 4:20 ` Nicolas Pitre [this message]
2016-07-20 4:20 ` [PATCH v3 11/12] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
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