From 0d5a18eb1daeffe4bd24fe27b154b0fd6af897aa Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Mon, 13 Jul 2020 20:34:17 +0100 Subject: [PATCH] Fix sbrk in PIE binaries In PIE mode, the program gets loaded at very low address, and thus _end is very low, just before libraries, and thus initializing the brk to it does not make sense, since there is no room left there. Hardcode the brk to 0x8000000 for now as a workaround. Signed-off-by: Samuel Thibault Gbp-Pq: Topic hurd-i386 Gbp-Pq: Name tg-pie-sbrk.diff --- sysdeps/mach/hurd/brk.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/sysdeps/mach/hurd/brk.c b/sysdeps/mach/hurd/brk.c index 4fac03fcc..9cc4502f6 100644 --- a/sysdeps/mach/hurd/brk.c +++ b/sysdeps/mach/hurd/brk.c @@ -143,8 +143,12 @@ init_brk (void) /* If _hurd_brk is already set, don't change it. The assumption is that it was set in a previous run before something like Emacs's unexec was called and dumped all the data up to the break at that point. */ - if (_hurd_brk == 0) + if (_hurd_brk == 0) { _hurd_brk = (vm_address_t) &_end; + if (_hurd_brk < 0x8000000) + /* XXX: PIE case, get out of library area */ + _hurd_brk = 0x8000000; + } pagend = round_page (_hurd_brk); -- 2.30.2