[PATCH v2 2/2] symbols: also special-case symbols aliasing _sinittext

A recent 4.22 randconfig build job hit a situation where (LIVEPATCH=n,
i.e. --all-symbols not specified) both __note_gnu_build_id_end and
_erodata aliased _sinittext on the 1st linking pass, but they didn't on
the 2nd one. As a result two fewer symbols were emitted on the 2nd pass,
causing $(call compare-symbol-tables, ...) to fail.

Extend the existing "corner case" by also considering aliases with
_sinittext (_stext really shouldn't have anything ahead of it), but
discard only non-text symbols.

Signed-off-by: Jan Beulich <[email protected]>
---
v2: Re-base over _{s,e}extratext removal. Add const to cast.

--- a/xen/tools/symbols.c
+++ b/xen/tools/symbols.c
@@ -217,6 +217,11 @@ static int symbol_valid(struct sym_entry
 		if ((s->addr == _etext && strcmp((char*)s->sym + offset, "_etext")) ||
 		    (s->addr == _einittext && strcmp((char*)s->sym + offset, "_einittext")))
 			return 0;
+		/* Same for non-text aliases of _sinittext or _sextratext. */
+		if (toupper(*s->sym) != 'T'
+		    && s->addr == _sinittext
+		    && strcmp((const char *)s->sym + offset, "_sinittext"))
+			return 0;
 	}
 
 	/* Exclude symbols which vary between passes. */