diff options
| author | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-09-08 13:36:54 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-09-19 09:18:34 -0700 |
| commit | 748c90c693363d05c6b2f3915edc7999a2f71837 (patch) | |
| tree | 759d5dcfb0efdf41fdc30052a48ec555270ceca5 | |
| parent | 331955600ddf55a2c6d92a00f95b0865f1c74fc3 (diff) | |
x86/shstk: Remove useless clone error handling
When clone fails after the shadow stack is allocated, any allocated shadow
stack is cleaned up in exit_thread() in copy_process(). So the logic in
copy_thread() is unneeded, and also will not handle failures that happen
outside of copy_thread().
In addition, since there is a second attempt to unmap the same shadow
stack, there is a race where an newly mapped region could get unmapped.
So remove the logic in copy_thread() and rely on exit_thread() to handle
clone failure.
Fixes: b2926a36b97a ("x86/shstk: Handle thread shadow stack")
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: H.J. Lu <hjl.tools@gmail.com>
Link: https://lore.kernel.org/all/20230908203655.543765-3-rick.p.edgecombe%40intel.com
| -rw-r--r-- | arch/x86/kernel/process.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 9f0909142a0a..b6f4e8399fca 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -257,13 +257,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (!ret && unlikely(test_tsk_thread_flag(current, TIF_IO_BITMAP))) io_bitmap_share(p); - /* - * If copy_thread() if failing, don't leak the shadow stack possibly - * allocated in shstk_alloc_thread_stack() above. - */ - if (ret) - shstk_free(p); - return ret; } |