diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2021-01-10 19:05:08 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2021-01-26 22:11:38 +0100 |
| commit | 2fcb4090cd7352665ecb756990a3087bfd86a295 (patch) | |
| tree | 4562c5264a7b6326b8cdf82ebe379bc351ab58d4 /arch/um/os-Linux | |
| parent | f4172b084342fd3f9e38c10650ffe19eac30d8ce (diff) | |
Revert "um: allocate a guard page to helper threads"
This reverts commit ef4459a6da09 ("um: allocate a guard page to
helper threads"), it's broken in multiple ways:
1) the free no longer matches the alloc; and
2) more importantly, the set_memory_ro() causes allocation of
page tables for the normal memory that doesn't have any,
and that later causes corruption and crashes (usually but
not always in vfree()).
We could fix the first bug and use vmalloc() to work around the
second, but set_memory_ro() actually doesn't do anything either
so I'll just revert that as well.
Reported-by: Benjamin Berg <benjamin@sipsolutions.net>
Fixes: ef4459a6da09 ("um: allocate a guard page to helper threads")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/os-Linux')
| -rw-r--r-- | arch/um/os-Linux/helper.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index feb48d796e00..9fa6e4187d4f 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -45,7 +45,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) unsigned long stack, sp; int pid, fds[2], ret, n; - stack = alloc_stack(__cant_sleep()); + stack = alloc_stack(0, __cant_sleep()); if (stack == 0) return -ENOMEM; @@ -116,7 +116,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, unsigned long stack, sp; int pid, status, err; - stack = alloc_stack(__cant_sleep()); + stack = alloc_stack(0, __cant_sleep()); if (stack == 0) return -ENOMEM; |