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add lock and error check in sys_brk

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This commit is contained in:
Masamichi Takagi m-takagi@ab.jp.nec.com
2012-11-27 16:12:39 +09:00
parent d4b186f1d8
commit b902a245e4
1 changed files with 28 additions and 6 deletions
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34
kernel/syscall.c
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@@ -100,13 +100,35 @@ long sys_brk(int n, aal_mc_user_context_t *ctx)
{
unsigned long address = aal_mc_syscall_arg0(ctx);
struct vm_regions *region = &cpu_local_var(current)->vm->region;
unsigned long r;
region->brk_end =
extend_process_region(cpu_local_var(current),
region->brk_start, region->brk_end,
address);
return region->brk_end;
dkprintf("SC(%d)[sys_brk] brk_start=%lx,end=%lx\n", aal_mc_get_processor_id(), region->brk_start, region->brk_end);
/* brk change fail, including glibc trick brk(0) to obtain current brk */
if(address < region->brk_start) {
r = region->brk_end;
goto out;
}
/* brk change fail, because we don't shrink memory region */
if(address < region->brk_end) {
r = region->brk_end;
goto out;
}
/* try to extend memory region */
unsigned long flags = aal_mc_spinlock_lock(&cpu_local_var(current)->vm->memory_range_lock);
region->brk_end =
extend_process_region(cpu_local_var(current),
region->brk_start, region->brk_end,
address);
aal_mc_spinlock_unlock(&cpu_local_var(current)->vm->memory_range_lock, flags);
dkprintf("SC(%d)[sys_brk] brk_end set to %lx\n", aal_mc_get_processor_id(), region->brk_end);
r = region->brk_end;
out:
return r;
}