svn commit: r333447 - in head/sys: ddb powerpc/include powerpc/pseries

[Justin Hibbits]

Author: jhibbits
Date: Thu May 10 03:59:48 2018
New Revision: 333447
URL: https://svnweb.freebsd.org/changeset/base/333447

Log:
  Fix PPC symbol resolution
  
  Summary:
  There were 2 issues that were preventing correct symbol resolution
  on PowerPC/pseries:
  
  1- memory corruption at chrp_attach() - this caused the inital
     part of the symbol table to become zeroed, which would cause
     the kernel linker to fail to parse it.
     (this was probably zeroing out other memory parts as well)
  
  2- DDB symbol resolution wasn't working because symtab contained
     not relocated addresses but it was given relocated offsets.
     Although relocating the symbol table fixed this, it broke the
     linker, that already handled this case.
     Thus, the fix for this consists in adding a new DDB macro:
     DB_STOFFS(offs) that converts a (potentially) relocated offset
     into one that can be compared with symbol table values.
  
  PR:		227093
  Submitted by:	Leandro Lupori <leandro.lupori_gmail.com>
  Differential Revision: https://reviews.freebsd.org/D15372

Modified:
  head/sys/ddb/db_main.c
  head/sys/ddb/ddb.h
  head/sys/powerpc/include/db_machdep.h
  head/sys/powerpc/pseries/platform_chrp.c

Modified: head/sys/ddb/db_main.c
==============================================================================
--- head/sys/ddb/db_main.c	Thu May 10 03:50:20 2018	(r333446)
+++ head/sys/ddb/db_main.c	Thu May 10 03:59:48 2018	(r333447)
@@ -100,6 +100,7 @@ X_db_search_symbol(db_symtab_t *symtab, db_addr_t off,
 	c_linker_sym_t lsym;
 	Elf_Sym *sym, *match;
 	unsigned long diff;
+	db_addr_t stoffs;
 
 	if (symtab->private == NULL) {
 		if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) {
@@ -111,19 +112,20 @@ X_db_search_symbol(db_symtab_t *symtab, db_addr_t off,
 
 	diff = ~0UL;
 	match = NULL;
+	stoffs = DB_STOFFS(off);
 	for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) {
 		if (sym->st_name == 0 || sym->st_shndx == SHN_UNDEF)
 			continue;
-		if (off < sym->st_value)
+		if (stoffs < sym->st_value)
 			continue;
 		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT &&
 		    ELF_ST_TYPE(sym->st_info) != STT_FUNC &&
 		    ELF_ST_TYPE(sym->st_info) != STT_NOTYPE)
 			continue;
-		if ((off - sym->st_value) > diff)
+		if ((stoffs - sym->st_value) > diff)
 			continue;
-		if ((off - sym->st_value) < diff) {
-			diff = off - sym->st_value;
+		if ((stoffs - sym->st_value) < diff) {
+			diff = stoffs - sym->st_value;
 			match = sym;
 		} else {
 			if (match == NULL)

Modified: head/sys/ddb/ddb.h
==============================================================================
--- head/sys/ddb/ddb.h	Thu May 10 03:50:20 2018	(r333446)
+++ head/sys/ddb/ddb.h	Thu May 10 03:59:48 2018	(r333447)
@@ -72,6 +72,10 @@ SYSCTL_DECL(_debug_ddb);
 #define	DB_MAXSCRIPTRECURSION	3
 #endif
 
+#ifndef DB_STOFFS
+#define DB_STOFFS(offs)		(offs)
+#endif
+
 #ifndef DB_CALL
 #define	DB_CALL	db_fncall_generic
 #else

Modified: head/sys/powerpc/include/db_machdep.h
==============================================================================
--- head/sys/powerpc/include/db_machdep.h	Thu May 10 03:50:20 2018	(r333446)
+++ head/sys/powerpc/include/db_machdep.h	Thu May 10 03:59:48 2018	(r333447)
@@ -85,4 +85,8 @@ typedef	intptr_t	db_expr_t;	/* expression - signed */
 #define	inst_load(ins)		0
 #define	inst_store(ins)		0
 
+#ifdef __powerpc64__
+#define DB_STOFFS(offs)		((offs) & ~DMAP_BASE_ADDRESS)
+#endif
+
 #endif	/* _POWERPC_DB_MACHDEP_H_ */

Modified: head/sys/powerpc/pseries/platform_chrp.c
==============================================================================
--- head/sys/powerpc/pseries/platform_chrp.c	Thu May 10 03:50:20 2018	(r333446)
+++ head/sys/powerpc/pseries/platform_chrp.c	Thu May 10 03:59:48 2018	(r333447)
@@ -146,7 +146,7 @@ chrp_attach(platform_t plat)
 
 		/* Set up important VPA fields */
 		for (i = 0; i < MAXCPU; i++) {
-			bzero(splpar_vpa[i], sizeof(splpar_vpa));
+			bzero(splpar_vpa[i], sizeof(splpar_vpa[i]));
 			/* First two: VPA size */
 			splpar_vpa[i][4] =
 			    (uint8_t)((sizeof(splpar_vpa[i]) >> 8) & 0xff);