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| author | James Hogan <james.hogan@imgtec.com> | 2014-05-13 23:58:24 +0100 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2014-05-15 00:00:35 +0100 |
| commit | d71f290b4e98a39f49f2595a13be3b4d5ce8e1f1 (patch) | |
| tree | b0547c265b8eb0d828ce47b9f4a20cc969d225e5 | |
| parent | 2425ce84026c385b73ae72039f90d042d49e0394 (diff) | |
| download | linux-d71f290b4e98a39f49f2595a13be3b4d5ce8e1f1.tar.gz | |
metag: Reduce maximum stack size to 256MB
Specify the maximum stack size for arches where the stack grows upward
(parisc and metag) in asm/processor.h rather than hard coding in
fs/exec.c so that metag can specify a smaller value of 256MB rather than
1GB.
This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased
beyond a safe value by root. E.g. when starting a process after running
"ulimit -H -s unlimited" it will then attempt to use a stack size of the
maximum 1GB which is far too big for metag's limited user virtual
address space (stack_top is usually 0x3ffff000):
BUG: failure at fs/exec.c:589/shift_arg_pages()!
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # only needed for >= v3.9 (arch/metag)
| -rw-r--r-- | arch/metag/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/parisc/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | fs/exec.c | 6 |
3 files changed, 7 insertions, 3 deletions
diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h index f16477d1f571cb..3be8581af4956a 100644 --- a/arch/metag/include/asm/processor.h +++ b/arch/metag/include/asm/processor.h @@ -22,6 +22,8 @@ /* Add an extra page of padding at the top of the stack for the guard page. */ #define STACK_TOP (TASK_SIZE - PAGE_SIZE) #define STACK_TOP_MAX STACK_TOP +/* Maximum virtual space for stack */ +#define STACK_SIZE_MAX (1 << 28) /* 256 MB */ /* This decides where the kernel will search for a free chunk of vm * space during mmap's. diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index 198a86feb5748f..86522ef09d524b 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -55,6 +55,8 @@ #define STACK_TOP TASK_SIZE #define STACK_TOP_MAX DEFAULT_TASK_SIZE +#define STACK_SIZE_MAX (1 << 30) /* 1 GB */ + #endif #ifndef __ASSEMBLY__ diff --git a/fs/exec.c b/fs/exec.c index 476f3ebf437ef4..238b7aa26f68ab 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -657,10 +657,10 @@ int setup_arg_pages(struct linux_binprm *bprm, unsigned long rlim_stack; #ifdef CONFIG_STACK_GROWSUP - /* Limit stack size to 1GB */ + /* Limit stack size */ stack_base = rlimit_max(RLIMIT_STACK); - if (stack_base > (1 << 30)) - stack_base = 1 << 30; + if (stack_base > STACK_SIZE_MAX) + stack_base = STACK_SIZE_MAX; /* Make sure we didn't let the argument array grow too large. */ if (vma->vm_end - vma->vm_start > stack_base) |