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authorRick Edgecombe <rick.p.edgecombe@intel.com>2023-09-08 13:36:54 -0700
committerDave Hansen <dave.hansen@linux.intel.com>2023-09-19 09:18:34 -0700
commit748c90c693363d05c6b2f3915edc7999a2f71837 (patch)
tree759d5dcfb0efdf41fdc30052a48ec555270ceca5 /arch/x86/kernel
parent331955600ddf55a2c6d92a00f95b0865f1c74fc3 (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
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/process.c7
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;
}