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relocate a program interpreter to the map_start

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This commit makes a system call that dereferences a NULL pointer fail.
This commit is contained in:
NAKAMURA Gou
2014-01-14 15:23:15 +09:00
parent 6992b829a0
commit c421965542
4 changed files with 33 additions and 3 deletions
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27
kernel/host.c
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@@ -67,6 +67,8 @@ static int process_msg_prepare_process(unsigned long rphys)
int range_npages;
void *up_v;
unsigned long flags;
uintptr_t interp_obase = -1;
uintptr_t interp_nbase = -1;
sz = sizeof(struct program_load_desc)
+ sizeof(struct program_image_section) * 16;
@@ -100,6 +102,8 @@ static int process_msg_prepare_process(unsigned long rphys)
proc->tid = pn->pid;
proc->vm->region.user_start = pn->user_start;
proc->vm->region.user_end = pn->user_end;
proc->vm->region.map_start = (USER_END / 3) & LARGE_PAGE_MASK;
proc->vm->region.map_end = proc->vm->region.map_start;
proc->rlimit_stack.rlim_cur = pn->rlimit_stack_cur;
proc->rlimit_stack.rlim_max = pn->rlimit_stack_max;
@@ -107,6 +111,18 @@ static int process_msg_prepare_process(unsigned long rphys)
cpu_local_var(scp).post_idx = 0;
for (i = 0; i < n; i++) {
if (pn->sections[i].interp && (interp_nbase == (uintptr_t)-1)) {
interp_obase = pn->sections[i].vaddr;
interp_obase -= (interp_obase % pn->interp_align);
interp_nbase = proc->vm->region.map_start;
interp_nbase = (interp_nbase + pn->interp_align - 1)
& ~(pn->interp_align - 1);
}
if (pn->sections[i].interp) {
pn->sections[i].vaddr -= interp_obase;
pn->sections[i].vaddr += interp_nbase;
p->sections[i].vaddr = pn->sections[i].vaddr;
}
s = (pn->sections[i].vaddr) & PAGE_MASK;
e = (pn->sections[i].vaddr + pn->sections[i].len
+ PAGE_SIZE - 1) & PAGE_MASK;
@@ -153,7 +169,7 @@ static int process_msg_prepare_process(unsigned long rphys)
/* TODO: Maybe we need flag */
if (pn->sections[i].interp) {
/* nothing to do */
proc->vm->region.map_end = e;
}
else if (i == 0) {
proc->vm->region.text_start = s;
@@ -171,6 +187,13 @@ static int process_msg_prepare_process(unsigned long rphys)
}
}
if (interp_nbase != (uintptr_t)-1) {
pn->entry -= interp_obase;
pn->entry += interp_nbase;
p->entry = pn->entry;
ihk_mc_modify_user_context(proc->uctx, IHK_UCR_PROGRAM_COUNTER, pn->entry);
}
#if 1
/*
Fix for the problem where brk grows to hit .bss section
@@ -188,8 +211,6 @@ static int process_msg_prepare_process(unsigned long rphys)
proc->vm->region.brk_start = proc->vm->region.brk_end =
proc->vm->region.data_end;
#endif
proc->vm->region.map_start = proc->vm->region.map_end =
(USER_END / 3) & LARGE_PAGE_MASK;
/* Map system call stuffs */
flags = VR_RESERVED | VR_PROT_READ | VR_PROT_WRITE;

1
kernel/include/syscall.h
View File

@@ -122,6 +122,7 @@ struct program_load_desc {
unsigned long envs_len;
unsigned long rlimit_stack_cur;
unsigned long rlimit_stack_max;
unsigned long interp_align;
struct program_image_section sections[0];
};