diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2020-12-05 21:50:18 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2020-12-13 22:38:06 +0100 |
| commit | ef4459a6da0955b533ebfc97a7d756ac090f50c9 (patch) | |
| tree | 5c1153080467c99b2f60942757f644d38338319b /arch/um/drivers | |
| parent | 963285b0b47a1b8e1dfa5481717855a7057ccec6 (diff) | |
| download | linux-ef4459a6da0955b533ebfc97a7d756ac090f50c9.tar.bz2 | |
um: allocate a guard page to helper threads
We've been running into stack overflows in helper threads
corrupting memory (e.g. because somebody put printf() or
os_info() there), so to avoid those causing hard-to-debug
issues later on, allocate a guard page for helper thread
stacks and mark it read-only.
Unfortunately, the crash dump at that point is useless as
the stack tracer will try to backtrace the *kernel* thread,
not the helper thread, but at least we don't survive to a
random issue caused by corruption.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/drivers')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 7e07b321e847..13b1fe694b90 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1241,7 +1241,7 @@ static int __init ubd_driver_init(void){ /* Letting ubd=sync be like using ubd#s= instead of ubd#= is * enough. So use anyway the io thread. */ } - stack = alloc_stack(0, 0); + stack = alloc_stack(0); io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), &thread_fd); if(io_pid < 0){ |