diff options
| -rw-r--r-- | arch/powerpc/mm/fault.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 641fc5f3d7dd..3ebb1792e636 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -267,6 +267,9 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code, return false; } +// This comes from 64-bit struct rt_sigframe + __SIGNAL_FRAMESIZE +#define SIGFRAME_MAX_SIZE (4096 + 128) + static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, struct vm_area_struct *vma, unsigned int flags, bool *must_retry) @@ -274,7 +277,7 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, /* * N.B. The POWER/Open ABI allows programs to access up to * 288 bytes below the stack pointer. - * The kernel signal delivery code writes up to about 1.5kB + * The kernel signal delivery code writes a bit over 4KB * below the stack pointer (r1) before decrementing it. * The exec code can write slightly over 640kB to the stack * before setting the user r1. Thus we allow the stack to @@ -299,7 +302,7 @@ static bool bad_stack_expansion(struct pt_regs *regs, unsigned long address, * between the last mapped region and the stack will * expand the stack rather than segfaulting. */ - if (address + 2048 >= uregs->gpr[1]) + if (address + SIGFRAME_MAX_SIZE >= uregs->gpr[1]) return false; if ((flags & FAULT_FLAG_WRITE) && (flags & FAULT_FLAG_USER) && |