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authorKees Cook <keescook@chromium.org>2021-04-01 16:23:47 -0700
committerThomas Gleixner <tglx@linutronix.de>2021-04-08 14:05:20 +0200
commit68ef8735d253f3d840082b78f996bf2d89ee6e5f (patch)
tree56d0efc5657399b907ca874ddea2a8140c3976e9 /drivers/misc/lkdtm
parentfe950f6020338c8ac668ef823bb692d36b7542a2 (diff)
downloadlinux-68ef8735d253f3d840082b78f996bf2d89ee6e5f.tar.gz
lkdtm: Add REPORT_STACK for checking stack offsets
For validating the stack offset behavior, report the offset from a given process's first seen stack address. Add s script to calculate the results to the LKDTM kselftests. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210401232347.2791257-7-keescook@chromium.org
Diffstat (limited to 'drivers/misc/lkdtm')
-rw-r--r--drivers/misc/lkdtm/bugs.c17
-rw-r--r--drivers/misc/lkdtm/core.c1
-rw-r--r--drivers/misc/lkdtm/lkdtm.h1
3 files changed, 19 insertions, 0 deletions
diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 110f5a8538e96..0e8254d0cf0ba 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -134,6 +134,23 @@ noinline void lkdtm_CORRUPT_STACK_STRONG(void)
__lkdtm_CORRUPT_STACK((void *)&data);
}
+static pid_t stack_pid;
+static unsigned long stack_addr;
+
+void lkdtm_REPORT_STACK(void)
+{
+ volatile uintptr_t magic;
+ pid_t pid = task_pid_nr(current);
+
+ if (pid != stack_pid) {
+ pr_info("Starting stack offset tracking for pid %d\n", pid);
+ stack_pid = pid;
+ stack_addr = (uintptr_t)&magic;
+ }
+
+ pr_info("Stack offset: %d\n", (int)(stack_addr - (uintptr_t)&magic));
+}
+
void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
{
static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5};
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index b2aff4d87c014..8024b6a5cc7fc 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -110,6 +110,7 @@ static const struct crashtype crashtypes[] = {
CRASHTYPE(EXHAUST_STACK),
CRASHTYPE(CORRUPT_STACK),
CRASHTYPE(CORRUPT_STACK_STRONG),
+ CRASHTYPE(REPORT_STACK),
CRASHTYPE(CORRUPT_LIST_ADD),
CRASHTYPE(CORRUPT_LIST_DEL),
CRASHTYPE(STACK_GUARD_PAGE_LEADING),
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index 5ae48c64df24d..99f90d3e5e9cb 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -17,6 +17,7 @@ void lkdtm_LOOP(void);
void lkdtm_EXHAUST_STACK(void);
void lkdtm_CORRUPT_STACK(void);
void lkdtm_CORRUPT_STACK_STRONG(void);
+void lkdtm_REPORT_STACK(void);
void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void);
void lkdtm_SOFTLOCKUP(void);
void lkdtm_HARDLOCKUP(void);