ldso: support DT_RELR relative relocation format

this resolves DT_RELR relocations in non-ldso, dynamic-linked objects.

diff --git a/include/elf.h b/include/elf.h
index 86e2f0b..9e980a2 100644 (file)
--- a/include/elf.h
+++ b/include/elf.h
@@ -385,7 +385,8 @@ typedef struct {
 #define SHT_PREINIT_ARRAY 16
 #define SHT_GROUP        17
 #define SHT_SYMTAB_SHNDX  18
-#define        SHT_NUM           19
+#define SHT_RELR         19
+#define        SHT_NUM           20
 #define SHT_LOOS         0x60000000
 #define SHT_GNU_ATTRIBUTES 0x6ffffff5
 #define SHT_GNU_HASH     0x6ffffff6
@@ -754,7 +755,10 @@ typedef struct {
 #define DT_PREINIT_ARRAY 32
 #define DT_PREINIT_ARRAYSZ 33
 #define DT_SYMTAB_SHNDX        34
-#define        DT_NUM          35
+#define DT_RELRSZ      35
+#define DT_RELR                36
+#define DT_RELRENT     37
+#define        DT_NUM          38
 #define DT_LOOS                0x6000000d
 #define DT_HIOS                0x6ffff000
 #define DT_LOPROC      0x70000000

diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index cc67795..e92f03c 100644 (file)
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -210,7 +210,8 @@ static void decode_vec(size_t *v, size_t *a, size_t cnt)
        size_t i;
        for (i=0; i<cnt; i++) a[i] = 0;
        for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
-               a[0] |= 1UL<<v[0];
+               if (v[0] < 8*sizeof(long))
+                       a[0] |= 1UL<<v[0];
                a[v[0]] = v[1];
        }
 }
@@ -515,6 +516,23 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
        }
 }
 
+static void do_relr_relocs(struct dso *dso, size_t *relr, size_t relr_size)
+{
+       unsigned char *base = dso->base;
+       size_t *reloc_addr;
+       for (; relr_size; relr++, relr_size-=sizeof(size_t))
+               if ((relr[0]&1) == 0) {
+                       reloc_addr = laddr(dso, relr[0]);
+                       *reloc_addr++ += (size_t)base;
+               } else {
+                       int i = 0;
+                       for (size_t bitmap=relr[0]; (bitmap>>=1); i++)
+                               if (bitmap&1)
+                                       reloc_addr[i] += (size_t)base;
+                       reloc_addr += 8*sizeof(size_t)-1;
+               }
+}
+
 static void redo_lazy_relocs()
 {
        struct dso *p = lazy_head, *next;
@@ -1357,6 +1375,7 @@ static void reloc_all(struct dso *p)
                        2+(dyn[DT_PLTREL]==DT_RELA));
                do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
                do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
+               do_relr_relocs(p, laddr(p, dyn[DT_RELR]), dyn[DT_RELRSZ]);
 
                if (head != &ldso && p->relro_start != p->relro_end) {
                        long ret = __syscall(SYS_mprotect, laddr(p, p->relro_start),

diff --git a/src/internal/dynlink.h b/src/internal/dynlink.h
index 51c0639..830354e 100644 (file)
--- a/src/internal/dynlink.h
+++ b/src/internal/dynlink.h
@@ -93,7 +93,7 @@ struct fdpic_dummy_loadmap {
 #endif
 
 #define AUX_CNT 32
-#define DYN_CNT 32
+#define DYN_CNT 37
 
 typedef void (*stage2_func)(unsigned char *, size_t *);