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authorHelge Deller <deller@gmx.de>2014-04-30 23:26:02 +0200
committerJames Hogan <james.hogan@imgtec.com>2014-05-15 00:01:41 +0100
commit042d27acb64924a0e8a43e972485913a32407beb (patch)
tree0a0d7f6bc2fcf5dd1e12b7da481c22464fa3e859 /arch/parisc
parentd71f290b4e98a39f49f2595a13be3b4d5ce8e1f1 (diff)
downloadlinux-042d27acb64924a0e8a43e972485913a32407beb.tar.bz2
parisc,metag: Do not hardcode maximum userspace stack size
This patch affects only architectures where the stack grows upwards (currently parisc and metag only). On those do not hardcode the maximum initial stack size to 1GB for 32-bit processes, but make it configurable via a config option. The main problem with the hardcoded stack size is, that we have two memory regions which grow upwards: stack and heap. To keep most of the memory available for heap in a flexmap memory layout, it makes no sense to hard allocate up to 1GB of the memory for stack which can't be used as heap then. This patch makes the stack size for 32-bit processes configurable and uses 80MB as default value which has been in use during the last few years on parisc and which hasn't showed any problems yet. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: James Hogan <james.hogan@imgtec.com> 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>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/include/asm/processor.h5
-rw-r--r--arch/parisc/kernel/sys_parisc.c6
2 files changed, 7 insertions, 4 deletions
diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h
index 86522ef09d52..d951c9681ab3 100644
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -55,7 +55,10 @@
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX DEFAULT_TASK_SIZE
-#define STACK_SIZE_MAX (1 << 30) /* 1 GB */
+/* Allow bigger stacks for 64-bit processes */
+#define STACK_SIZE_MAX (USER_WIDE_MODE \
+ ? (1 << 30) /* 1 GB */ \
+ : (CONFIG_MAX_STACK_SIZE_MB*1024*1024))
#endif
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 31ffa9b55322..e1ffea2f9a0b 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -72,10 +72,10 @@ static unsigned long mmap_upper_limit(void)
{
unsigned long stack_base;
- /* Limit stack size to 1GB - see setup_arg_pages() in fs/exec.c */
+ /* Limit stack size - see setup_arg_pages() in fs/exec.c */
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;
return PAGE_ALIGN(STACK_TOP - stack_base);
}