| From: Vineet Gupta <vgupta@synopsys.com> |
| Date: Wed, 11 Jul 2018 10:42:20 -0700 |
| Subject: ARC: mm: allow mprotect to make stack mappings executable |
| |
| commit 93312b6da4df31e4102ce5420e6217135a16c7ea upstream. |
| |
| mprotect(EXEC) was failing for stack mappings as default vm flags was |
| missing MAYEXEC. |
| |
| This was triggered by glibc test suite nptl/tst-execstack testcase |
| |
| What is surprising is that despite running LTP for years on, we didn't |
| catch this issue as it lacks a directed test case. |
| |
| gcc dejagnu tests with nested functions also requiring exec stack work |
| fine though because they rely on the GNU_STACK segment spit out by |
| compiler and handled in kernel elf loader. |
| |
| This glibc case is different as the stack is non exec to begin with and |
| a dlopen of shared lib with GNU_STACK segment triggers the exec stack |
| proceedings using a mprotect(PROT_EXEC) which was broken. |
| |
| Signed-off-by: Vineet Gupta <vgupta@synopsys.com> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| arch/arc/include/asm/page.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/arc/include/asm/page.h |
| +++ b/arch/arc/include/asm/page.h |
| @@ -97,7 +97,7 @@ typedef unsigned long pgtable_t; |
| #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) |
| |
| /* Default Permissions for stack/heaps pages (Non Executable) */ |
| -#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE) |
| +#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) |
| |
| #define WANT_PAGE_VIRTUAL 1 |
| |
