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Diffstat (limited to 'arch/x86/um/shared/sysdep/stub_64.h')
-rw-r--r--arch/x86/um/shared/sysdep/stub_64.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h
index 294affbec742..9cfd31afa769 100644
--- a/arch/x86/um/shared/sysdep/stub_64.h
+++ b/arch/x86/um/shared/sysdep/stub_64.h
@@ -10,6 +10,7 @@
#include <sysdep/ptrace_user.h>
#include <generated/asm-offsets.h>
#include <linux/stddef.h>
+#include <asm/prctl.h>
#define STUB_MMAP_NR __NR_mmap
#define MMAP_OFFSET(o) (o)
@@ -134,4 +135,20 @@ static __always_inline void *get_stub_data(void)
"call *%%rax ;" \
:: "i" ((1 + STUB_DATA_PAGES) * UM_KERN_PAGE_SIZE), \
"i" (&fn))
+
+static __always_inline void
+stub_seccomp_restore_state(struct stub_data_arch *arch)
+{
+ /*
+ * We could use _writefsbase_u64/_writegsbase_u64 if the host reports
+ * support in the hwcaps (HWCAP2_FSGSBASE).
+ */
+ if (arch->sync & STUB_SYNC_FS_BASE)
+ stub_syscall2(__NR_arch_prctl, ARCH_SET_FS, arch->fs_base);
+ if (arch->sync & STUB_SYNC_GS_BASE)
+ stub_syscall2(__NR_arch_prctl, ARCH_SET_GS, arch->gs_base);
+
+ arch->sync = 0;
+}
+
#endif