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| author | Lai Jiangshan <laijs@linux.alibaba.com> | 2021-02-04 18:27:06 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-02-05 22:13:11 +0300 |
| commit | c4bed4b96918ff1d062ee81fdae4d207da4fa9b0 (patch) | |
| tree | c5fc2afad245c4b6f8116a139fbc3e5e2a8df1f5 /net/unix/af_unix.c | |
| parent | 25a068b8e9a4eb193d755d58efcb3c98928636e0 (diff) | |
| download | linux-c4bed4b96918ff1d062ee81fdae4d207da4fa9b0.tar.xz | |
x86/debug: Prevent data breakpoints on __per_cpu_offset
When FSGSBASE is enabled, paranoid_entry() fetches the per-CPU GSBASE value
via __per_cpu_offset or pcpu_unit_offsets.
When a data breakpoint is set on __per_cpu_offset[cpu] (read-write
operation), the specific CPU will be stuck in an infinite #DB loop.
RCU will try to send an NMI to the specific CPU, but it is not working
either since NMI also relies on paranoid_entry(). Which means it's
undebuggable.
Fixes: eaad981291ee3("x86/entry/64: Introduce the FIND_PERCPU_BASE macro")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210204152708.21308-1-jiangshanlai@gmail.com
Diffstat (limited to 'net/unix/af_unix.c')
0 files changed, 0 insertions, 0 deletions