svn commit: r339876 - head/libexec/rtld-elf

[Konstantin Belousov]

On Fri, Nov 02, 2018 at 08:30:17AM -0700, Mark Millard wrote:
> Breakpoint 4, reloc_non_plt (obj=0x41041000, obj_rtld=0x1801cc7, flags=4, lockstate=0x0) at /usr/src/libexec/rtld-elf/powerpc/reloc.c:338
> 338				__syncicache(obj->mapbase + phdr->p_vaddr,
> 1: x/i $pc
> => 0x1012b90 <reloc_non_plt+276>:	lwz     r0,36(r29)
> (gdb) print/x obj->mapbase+phdr->p_vaddr
> $17 = 0x3000000
> (gdb) print/x obj->mapbase              
> $18 = 0x1800000
> (gdb) print/x phdr->p_vaddr
> $19 = 0x1800000
> (gdb) c
> Continuing.
> 
> Program received signal SIGSEGV, Segmentation fault.
> __syncicache (from=0x3000000, len=34112) at /usr/src/lib/libc/powerpc/gen/syncicache.c:94
> 94			__asm __volatile ("dcbst 0,%0" :: "r"(p));
> 1: x/i $pc
> => 0x10228b8 <__syncicache+96>:	dcbst   0,r11
> 
> 
> 
> It looks to me like the 0x1800000 component of the
> overall figure was double counted. ( phdr->p_vaddr
> would vary but obj->mapbase would not. )
> 
> Omit "obj->mapbase + "?
I used the wrong addend.  Try this fix.

diff --git a/libexec/rtld-elf/powerpc/reloc.c b/libexec/rtld-elf/powerpc/reloc.c
index e921a4dc7d1..fae28dd9224 100644
--- a/libexec/rtld-elf/powerpc/reloc.c
+++ b/libexec/rtld-elf/powerpc/reloc.c
@@ -294,6 +294,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
 {
 	const Elf_Rela *relalim;
 	const Elf_Rela *rela;
+	const Elf_Phdr *phdr;
 	SymCache *cache;
 	int r = -1;
 
@@ -327,8 +328,18 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
 	if (cache != NULL)
 		free(cache);
 
-	/* Synchronize icache for text seg in case we made any changes */
-	__syncicache(obj->mapbase, obj->textsize);
+	/*
+	 * Synchronize icache for executable segments in case we made
+	 * any changes.
+	 */
+	for (phdr = obj->phdr;
+	    (const char *)phdr < (const char *)obj->phdr + obj->phsize;
+	    phdr++) {
+		if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) {
+			__syncicache(obj->relocbase + phdr->p_vaddr,
+			    phdr->p_memsz);
+		}
+	}
 
 	return (r);
 }
diff --git a/libexec/rtld-elf/powerpc64/reloc.c b/libexec/rtld-elf/powerpc64/reloc.c
index c2d6dac13b1..15f31738ab7 100644
--- a/libexec/rtld-elf/powerpc64/reloc.c
+++ b/libexec/rtld-elf/powerpc64/reloc.c
@@ -291,6 +291,7 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
 {
 	const Elf_Rela *relalim;
 	const Elf_Rela *rela;
+	const Elf_Phdr *phdr;
 	SymCache *cache;
 	int bytes = obj->dynsymcount * sizeof(SymCache);
 	int r = -1;
@@ -327,8 +328,18 @@ reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld, int flags,
 	if (cache)
 		munmap(cache, bytes);
 
-	/* Synchronize icache for text seg in case we made any changes */
-	__syncicache(obj->mapbase, obj->textsize);
+	/*
+	 * Synchronize icache for executable segments in case we made
+	 * any changes.
+	 */
+	for (phdr = obj->phdr;
+	    (const char *)phdr < (const char *)obj->phdr + obj->phsize;
+	    phdr++) {
+		if (phdr->p_type == PT_LOAD && (phdr->p_flags & PF_X) != 0) {
+			__syncicache(obj->relocbase + phdr->p_vaddr,
+			    phdr->p_memsz);
+		}
+	}
 
 	return (r);
 }