@@ -167,4 +167,8 @@ void int3_emulate_ret(struct pt_regs *regs)
}
#endif /* !CONFIG_UML_X86 */
+#if IS_BUILTIN(CONFIG_LKDTM)
+unsigned long read_cpu_patching_addr(unsigned int cpu);
+#endif
+
#endif /* _ASM_X86_TEXT_PATCHING_H */
@@ -773,6 +773,13 @@ static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
__ro_after_init struct mm_struct *poking_mm;
__ro_after_init unsigned long poking_addr;
+#if IS_BUILTIN(CONFIG_LKDTM)
+unsigned long read_cpu_patching_addr(unsigned int cpu)
+{
+ return poking_addr;
+}
+#endif
+
static void *__text_poke(void *addr, const void *opcode, size_t len)
{
bool cross_page_boundary = offset_in_page(addr) + len > PAGE_SIZE;
When live patching with STRICT_KERNEL_RWX a mapping is installed at a "patching address" with temporary write permissions. Provide a LKDTM-only accessor function for this address in preparation for a LKDTM test which attempts to "hijack" this mapping by writing to it from another CPU. Signed-off-by: Christopher M. Riedl <cmr@linux.ibm.com> --- arch/x86/include/asm/text-patching.h | 4 ++++ arch/x86/kernel/alternative.c | 7 +++++++ 2 files changed, 11 insertions(+)