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 11/12] binfmt_flat: add MMU-specific support
Date: Wed, 20 Jul 2016 00:20:23 -0400 [thread overview]
Message-ID: <1468988424-32671-12-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1468988424-32671-1-git-send-email-nicolas.pitre@linaro.org>
Not much else to do at this point except for the different stack setups.
SuperH and Xtensa could be added to the allowed list if they implement
__put_user_unaligned() and __get_user_unaligned().
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
---
fs/Kconfig.binfmt | 3 ++-
fs/binfmt_flat.c | 16 +++++++++++++---
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 72c03354c1..4c09d93d95 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -89,7 +89,8 @@ config BINFMT_SCRIPT
config BINFMT_FLAT
bool "Kernel support for flat binaries"
- depends on !MMU && (!FRV || BROKEN)
+ depends on !MMU || ARM || M68K
+ depends on !FRV || BROKEN
help
Support uClinux FLAT format binaries.
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index fef94aaa36..d04188267a 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -541,7 +541,7 @@ static int load_flat_file(struct linux_binprm * bprm,
* case, and then the fully copied to RAM case which lumps
* it all together.
*/
- if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
+ if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
/*
* this should give us a ROM ptr, but if it doesn't we don't
* really care
@@ -682,7 +682,9 @@ static int load_flat_file(struct linux_binprm * bprm,
*/
current->mm->start_brk = datapos + data_len + bss_len;
current->mm->brk = (current->mm->start_brk + 3) & ~3;
+#ifndef CONFIG_MMU
current->mm->context.end_brk = memp + memp_size - stack_len;
+#endif
}
if (flags & FLAT_FLAG_KTRACE) {
@@ -873,7 +875,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
{
struct lib_info libinfo;
struct pt_regs *regs = current_pt_regs();
- unsigned long stack_len;
+ unsigned long stack_len = 0;
unsigned long start_addr;
int res;
int i, j;
@@ -887,7 +889,9 @@ static int load_flat_binary(struct linux_binprm * bprm)
* pedantic and include space for the argv/envp array as it may have
* a lot of entries.
*/
- stack_len = PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#ifndef CONFIG_MMU
+ stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#endif
stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
@@ -915,6 +919,11 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
+#ifdef CONFIG_MMU
+ res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
+ if (!res)
+ res = create_flat_tables(bprm, bprm->p);
+#else
/* Stash our initial stack pointer into the mm structure */
current->mm->start_stack =
((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
@@ -924,6 +933,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
if (!res)
res = create_flat_tables(bprm, current->mm->start_stack);
+#endif
if (res)
return res;
--
2.7.4
next prev parent reply other threads:[~2016-07-20 4:20 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 ` [PATCH v3 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
2016-07-20 4:20 ` Nicolas Pitre [this message]
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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