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authorPeter Zijlstra <peterz@infradead.org>2022-10-18 13:49:21 +0200
committerPeter Zijlstra <peterz@infradead.org>2022-10-20 17:10:27 +0200
commit883bbbffa5a4ffd1915f8b42934dab81b7f87226 (patch)
tree6d650ad1ce9df229da9d3786bfc26d38c4f9466f /include/asm-generic
parentb5f1fc3184405ab955db1b86d41d8b744d07c12d (diff)
ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()
Different function signatures means they needs to be different functions; otherwise CFI gets upset. As triggered by the ftrace boot tests: [] CFI failure at ftrace_return_to_handler+0xac/0x16c (target: ftrace_stub+0x0/0x14; expected type: 0x0a5d5347) Fixes: 3c516f89e17e ("x86: Add support for CONFIG_CFI_CLANG") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/Y06dg4e1xF6JTdQq@hirez.programming.kicks-ass.net
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/vmlinux.lds.h18
1 files changed, 12 insertions, 6 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c15de165ec8f..d06ada2341cb 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -162,6 +162,16 @@
#define PATCHABLE_DISCARDS *(__patchable_function_entries)
#endif
+#ifndef CONFIG_ARCH_SUPPORTS_CFI_CLANG
+/*
+ * Simply points to ftrace_stub, but with the proper protocol.
+ * Defined by the linker script in linux/vmlinux.lds.h
+ */
+#define FTRACE_STUB_HACK ftrace_stub_graph = ftrace_stub;
+#else
+#define FTRACE_STUB_HACK
+#endif
+
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
/*
* The ftrace call sites are logged to a section whose name depends on the
@@ -169,10 +179,6 @@
* FTRACE_CALLSITE_SECTION. We capture all of them here to avoid header
* dependencies for FTRACE_CALLSITE_SECTION's definition.
*
- * Need to also make ftrace_stub_graph point to ftrace_stub
- * so that the same stub location may have different protocols
- * and not mess up with C verifiers.
- *
* ftrace_ops_list_func will be defined as arch_ftrace_ops_list_func
* as some archs will have a different prototype for that function
* but ftrace_ops_list_func() will have a single prototype.
@@ -182,11 +188,11 @@
KEEP(*(__mcount_loc)) \
KEEP_PATCHABLE \
__stop_mcount_loc = .; \
- ftrace_stub_graph = ftrace_stub; \
+ FTRACE_STUB_HACK \
ftrace_ops_list_func = arch_ftrace_ops_list_func;
#else
# ifdef CONFIG_FUNCTION_TRACER
-# define MCOUNT_REC() ftrace_stub_graph = ftrace_stub; \
+# define MCOUNT_REC() FTRACE_STUB_HACK \
ftrace_ops_list_func = arch_ftrace_ops_list_func;
# else
# define MCOUNT_REC()