From acdcdf047b0d4d7bd514025dd7e412dab98aaeee Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Fri, 3 Nov 2006 03:07:56 +0000 Subject: [PATCH] Clarify purpose and rationale. From Godmar Back. --- src/tests/userprog/sc-bad-sp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/src/tests/userprog/sc-bad-sp.c b/src/tests/userprog/sc-bad-sp.c index 56a5b8d..6da4a6e 100644 --- a/src/tests/userprog/sc-bad-sp.c +++ b/src/tests/userprog/sc-bad-sp.c @@ -1,6 +1,13 @@ /* Invokes a system call with the stack pointer (%esp) set to a bad address. The process must be terminated with -1 exit - code. */ + code. + + For Project 3: The bad address lies approximately 64MB below + the code segment, so there is no ambiguity that this attempt + must be rejected even after stack growth is implemented. + Moreover, a good stack growth heuristics should probably not + grow the stack for the purpose of reading the system call + number and arguments. */ #include "tests/lib.h" #include "tests/main.h" @@ -8,6 +15,6 @@ void test_main (void) { - asm volatile ("movl $0x20101234, %esp; int $0x30"); + asm volatile ("movl . - (64*1024*1024), %esp; int $0x30"); fail ("should have called exit(-1)"); } -- 2.30.2