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| author | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-06-12 17:10:52 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-08-02 15:01:50 -0700 |
| commit | 98cfa4630912a80a575277d1bf193376ba66116a (patch) | |
| tree | 1d861154e8be4b5e1c6adb37bafd95f30ddabbc1 /arch/x86/kernel/process_64.c | |
| parent | 6ee836687a3f39f92da790d33fa9694fe0143410 (diff) | |
| download | lwn-98cfa4630912a80a575277d1bf193376ba66116a.tar.gz lwn-98cfa4630912a80a575277d1bf193376ba66116a.zip | |
x86: Introduce userspace API for shadow stack
Add three new arch_prctl() handles:
- ARCH_SHSTK_ENABLE/DISABLE enables or disables the specified
feature. Returns 0 on success or a negative value on error.
- ARCH_SHSTK_LOCK prevents future disabling or enabling of the
specified feature. Returns 0 on success or a negative value
on error.
The features are handled per-thread and inherited over fork(2)/clone(2),
but reset on exec().
Co-developed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-27-rick.p.edgecombe%40intel.com
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 3d181c16a2f6..0f89aa0186d1 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -515,6 +515,8 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip, load_gs_index(__USER_DS); } + reset_thread_features(); + loadsegment(fs, 0); loadsegment(es, _ds); loadsegment(ds, _ds); @@ -894,6 +896,10 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) else return put_user(LAM_U57_BITS, (unsigned long __user *)arg2); #endif + case ARCH_SHSTK_ENABLE: + case ARCH_SHSTK_DISABLE: + case ARCH_SHSTK_LOCK: + return shstk_prctl(task, option, arg2); default: ret = -EINVAL; break; |