objtool: Fix up some outdated references to ENTRY/ENDPROC

ENTRY and ENDPROC were deprecated years ago and replaced with
SYM_FUNC_{START,END}.  Fix up a few outdated references in the objtool
documentation and comments.  Also fix a few typos.

Suggested-by: Brendan Jackman <jackmanb@google.com>
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/5eb7e06e1a0e87aaeda8d583ab060e7638a6ea8e.1742852846.git.jpoimboe@kernel.org

Author: jpoimboe

include/linux/linkage.h

@@ -134,10 +134,6 @@
 	.size name, .-name
 #endif
 
-/* If symbol 'name' is treated as a subroutine (gets called, and returns)
- * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of
- * static analysis tools such as stack depth analyzer.
- */
 #ifndef ENDPROC
 /* deprecated, use SYM_FUNC_END */
 #define ENDPROC(name) \

include/linux/objtool.h

@@ -69,7 +69,7 @@
  * In asm, there are two kinds of code: normal C-type callable functions and
  * the rest.  The normal callable functions can be called by other code, and
  * don't do anything unusual with the stack.  Such normal callable functions
- * are annotated with the ENTRY/ENDPROC macros.  Most asm code falls in this
+ * are annotated with SYM_FUNC_{START,END}.  Most asm code falls in this
  * category.  In this case, no special debugging annotations are needed because
  * objtool can automatically generate the ORC data for the ORC unwinder to read
  * at runtime.

tools/objtool/Documentation/objtool.txt

@@ -34,7 +34,7 @@ Objtool has the following features:
 - Return thunk annotation -- annotates all return thunk sites so kernel
   can patch them inline, depending on enabled mitigations
 
-- Return thunk training valiation -- validate that all entry paths
+- Return thunk untraining validation -- validate that all entry paths
   untrain a "safe return" before the first return (or call)
 
 - Non-instrumentation validation -- validates non-instrumentable
@@ -281,8 +281,8 @@ the objtool maintainers.
    If the error is for an asm file, and func() is indeed a callable
    function, add proper frame pointer logic using the FRAME_BEGIN and
    FRAME_END macros.  Otherwise, if it's not a callable function, remove
-   its ELF function annotation by changing ENDPROC to END, and instead
-   use the manual unwind hint macros in asm/unwind_hints.h.
+   its ELF function annotation by using SYM_CODE_{START,END} and use the
+   manual unwind hint macros in asm/unwind_hints.h.
 
    If it's a GCC-compiled .c file, the error may be because the function
    uses an inline asm() statement which has a "call" instruction.  An
@@ -352,7 +352,7 @@ the objtool maintainers.
    This is a kernel entry/exit instruction like sysenter or iret.  Such
    instructions aren't allowed in a callable function, and are most
    likely part of the kernel entry code.  Such code should probably be
-   placed in a SYM_FUNC_CODE block with unwind hints.
+   placed in a SYM_CODE_{START,END} block with unwind hints.
 
 
 6. file.o: warning: objtool: func()+0x26: sibling call from callable instruction with modified stack frame
@@ -381,7 +381,7 @@ the objtool maintainers.
 
    Another possibility is that the code has some asm or inline asm which
    does some unusual things to the stack or the frame pointer.  In such
-   cases it's probably appropriate to use SYM_FUNC_CODE with unwind
+   cases it's probably appropriate to use SYM_CODE_{START,END} with unwind
    hints.