linux-next: manual merge of the ftrace tree with the arm64 tree

From: Stephen Rothwell
Date: Sun Nov 24 2019 - 21:32:10 EST


Hi all,

Today's linux-next merge of the ftrace tree got a conflict in:

include/asm-generic/vmlinux.lds.h

between commit:

a1326b17ac03 ("module/ftrace: handle patchable-function-entry")

from the arm64 tree and commits:

b83b43ffc6e4 ("fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub")
46f9469247c6 ("ftrace: Rename ftrace_graph_stub to ftrace_stub_graph")

from the ftrace tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging. You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

--
Cheers,
Stephen Rothwell

diff --cc include/asm-generic/vmlinux.lds.h
index 63cedc3c0c77,996db32c491b..000000000000
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@@ -136,19 -110,30 +136,28 @@@
#endif

#ifdef CONFIG_FTRACE_MCOUNT_RECORD
-#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
/*
+ * The ftrace call sites are logged to a section whose name depends on the
+ * compiler option used. A given kernel image will only use one, AKA
+ * 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.
*/
-#define MCOUNT_REC() . = ALIGN(8); \
- __start_mcount_loc = .; \
- KEEP(*(__patchable_function_entries)) \
- __stop_mcount_loc = .; \
- ftrace_stub_graph = ftrace_stub;
-#else
#define MCOUNT_REC() . = ALIGN(8); \
__start_mcount_loc = .; \
KEEP(*(__mcount_loc)) \
+ KEEP(*(__patchable_function_entries)) \
- __stop_mcount_loc = .;
+ __stop_mcount_loc = .; \
+ ftrace_stub_graph = ftrace_stub;
-#endif
#else
- #define MCOUNT_REC()
+ # ifdef CONFIG_FUNCTION_TRACER
+ # define MCOUNT_REC() ftrace_stub_graph = ftrace_stub;
+ # else
+ # define MCOUNT_REC()
+ # endif
#endif

#ifdef CONFIG_TRACE_BRANCH_PROFILING

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