This patch adds new mmap flag - mmap_stack - that is used when mmaping
a stack when creating new pthread. This new flag is only used when
the build parameter CONF_lazy_stack is enabled.
Signed-off-by: Waldemar Kozaczuk <jwkozac...@gmail.com>
---
include/osv/mmu-defs.hh | 1 +
libc/mman.cc | 7 +------
libc/pthread.cc | 7 ++++++-
3 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/include/osv/mmu-defs.hh b/include/osv/mmu-defs.hh
index 18edf441..694815f8 100644
--- a/include/osv/mmu-defs.hh
+++ b/include/osv/mmu-defs.hh
@@ -84,6 +84,7 @@ enum {
mmap_small = 1ul << 5,
mmap_jvm_balloon = 1ul << 6,
mmap_file = 1ul << 7,
+ mmap_stack = 1ul << 8,
};
enum {
diff --git a/libc/mman.cc b/libc/mman.cc
index 75a94eb0..115b0313 100644
--- a/libc/mman.cc
+++ b/libc/mman.cc
@@ -43,12 +43,7 @@ unsigned libc_flags_to_mmap(int flags)
mmap_flags |= mmu::mmap_populate;
}
if (flags & MAP_STACK) {
- // OSv currently requires that stacks be pinned (see issue #143). So
- // if an application wants to mmap() a stack for pthread_attr_setstack
- // and did us the courtesy of telling this to ue (via MAP_STACK),
- // let's return the courtesy by returning pre-faulted memory.
- // FIXME: If issue #143 is fixed, this workaround should be removed.
- mmap_flags |= mmu::mmap_populate;
+ mmap_flags |= mmu::mmap_stack;
}
if (flags & MAP_SHARED) {
mmap_flags |= mmu::mmap_shared;
diff --git a/libc/pthread.cc b/libc/pthread.cc
index cda6cf90..de5979e8 100644
--- a/libc/pthread.cc
+++ b/libc/pthread.cc
@@ -141,7 +141,12 @@ namespace pthread_private {
return {attr.stack_begin, attr.stack_size};
}
size_t size = attr.stack_size;
- void *addr = mmu::map_anon(nullptr, size, mmu::mmap_populate,
mmu::perm_rw);
+#if CONF_lazy_stack
+ unsigned stack_flags = mmu::mmap_stack;
+#else
+ unsigned stack_flags = mmu::mmap_populate;
+#endif
+ void *addr = mmu::map_anon(nullptr, size, stack_flags, mmu::perm_rw);
mmu::mprotect(addr, attr.guard_size, 0);
sched::thread::stack_info si{addr, size};
si.deleter = free_stack;
--
2.34.1
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