diff options
Diffstat (limited to 'drivers/misc/lkdtm/perms.c')
| -rw-r--r-- | drivers/misc/lkdtm/perms.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 5b861dbff27e..6c24426104ba 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -29,6 +29,13 @@ static const unsigned long rodata = 0xAA55AA55; static unsigned long ro_after_init __ro_after_init = 0x55AA5500; /* + * This is a pointer to do_nothing() which is initialized at runtime rather + * than build time to avoid objtool IBT validation warnings caused by an + * inlined unrolled memcpy() in execute_location(). + */ +static void __ro_after_init *do_nothing_ptr; + +/* * This just returns to the caller. It is designed to be copied into * non-executable memory regions. */ @@ -65,13 +72,12 @@ static noinline __nocfi void execute_location(void *dst, bool write) { void (*func)(void); func_desc_t fdesc; - void *do_nothing_text = dereference_function_descriptor(do_nothing); - pr_info("attempting ok execution at %px\n", do_nothing_text); + pr_info("attempting ok execution at %px\n", do_nothing_ptr); do_nothing(); if (write == CODE_WRITE) { - memcpy(dst, do_nothing_text, EXEC_SIZE); + memcpy(dst, do_nothing_ptr, EXEC_SIZE); flush_icache_range((unsigned long)dst, (unsigned long)dst + EXEC_SIZE); } @@ -267,6 +273,8 @@ static void lkdtm_ACCESS_NULL(void) void __init lkdtm_perms_init(void) { + do_nothing_ptr = dereference_function_descriptor(do_nothing); + /* Make sure we can write to __ro_after_init values during __init */ ro_after_init |= 0xAA; } |