From 17d684c996c880ffe1103d94a072dba8cdb52905 Mon Sep 17 00:00:00 2001 From: Nilay Vaish Date: Sat, 22 Oct 2022 15:23:22 -0700 Subject: [PATCH origin/google/grte/v5-2.27/master] nptl: use mmap and munmap for stack allocation To: libc-alpha@sourceware.org Cc: maskray@google.com, dxf@google.com We made this change so that we can capture thread stack allocations. __mmap and __munmap cannot be overridden at runtime. mmap and munmap can be overidden at runtime and we are thus able to capture when either of these functions were called. --- nptl/allocatestack.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 9f6a75695e..1989ca7c86 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -276,7 +276,7 @@ __free_stacks (size_t limit) /* Remove this block. This should never fail. If it does something is really wrong. */ - if (__munmap (curr->stackblock, curr->stackblock_size) != 0) + if (munmap (curr->stackblock, curr->stackblock_size) != 0) abort (); /* Maybe we have freed enough. */ @@ -558,7 +558,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, /* If a guard page is required, avoid committing memory by first allocate with PROT_NONE and then reserve with required permission excluding the guard page. */ - mem = __mmap (NULL, size, (guardsize == 0) ? prot : PROT_NONE, + mem = mmap (NULL, size, (guardsize == 0) ? prot : PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); if (__glibc_unlikely (mem == MAP_FAILED)) @@ -585,7 +585,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, pagesize_m1); if (setup_stack_prot (mem, size, guard, guardsize, prot) != 0) { - __munmap (mem, size); + munmap (mem, size); return errno; } } @@ -628,7 +628,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, assert (errno == ENOMEM); /* Free the stack memory we just allocated. */ - (void) __munmap (mem, size); + (void) munmap (mem, size); return errno; } -- 2.38.0.135.g90850a2211-goog