mirror of https://github.com/torvalds/linux.git
526940e396
arm64 uses SP_EL0 to save the current task_struct address. While running in EL0, SP_EL0 is clobbered by userspace. So if the upper bit is not 1 (not TTBR1), the current address is invalid. This patch checks the upper bit of SP_EL0, if the upper bit is 1, lx_current() of arm64 will return the derefrence of current task. Otherwise, lx_current() will tell users they are running in userspace(EL0). While arm64 is running in EL0, it is actually pointless to print current task as the memory of kernel space is not accessible in EL0. Link: https://lkml.kernel.org/r/20210314203444.15188-3-song.bao.hua@hisilicon.com Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kieran Bingham <kbingham@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|---|---|---|
| .. | ||
| kunit | ||
| checkpatch.rst | ||
| coccinelle.rst | ||
| gcov.rst | ||
| gdb-kernel-debugging.rst | ||
| index.rst | ||
| kasan.rst | ||
| kcov.rst | ||
| kcsan.rst | ||
| kfence.rst | ||
| kgdb.rst | ||
| kmemleak.rst | ||
| kselftest.rst | ||
| sparse.rst | ||
| testing-overview.rst | ||
| ubsan.rst | ||