nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 34 insertions, 9 deletions

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index a5066b1c3de..4f8c3cba8c0 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -39,8 +39,6 @@ struct mips_hi16 {
 	Elf_Addr value;
 };
 
-static struct mips_hi16 *mips_hi16_list;
-
 static LIST_HEAD(dbe_list);
 static DEFINE_SPINLOCK(dbe_lock);
 
@@ -128,8 +126,8 @@ static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 
 	n->addr = (Elf_Addr *)location;
 	n->value = v;
-	n->next = mips_hi16_list;
-	mips_hi16_list = n;
+	n->next = me->arch.r_mips_hi16_list;
+	me->arch.r_mips_hi16_list = n;
 
 	return 0;
 }
@@ -142,18 +140,28 @@ static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
 	return 0;
 }
 
+static void free_relocation_chain(struct mips_hi16 *l)
+{
+	struct mips_hi16 *next;
+
+	while (l) {
+		next = l->next;
+		kfree(l);
+		l = next;
+	}
+}
+
 static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 {
 	unsigned long insnlo = *location;
+	struct mips_hi16 *l;
 	Elf_Addr val, vallo;
 
 	/* Sign extend the addend we extract from the lo insn.  */
 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
 
-	if (mips_hi16_list != NULL) {
-		struct mips_hi16 *l;
-
-		l = mips_hi16_list;
+	if (me->arch.r_mips_hi16_list != NULL) {
+		l = me->arch.r_mips_hi16_list;
 		while (l != NULL) {
 			struct mips_hi16 *next;
 			unsigned long insn;
@@ -188,7 +196,7 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 			l = next;
 		}
 
-		mips_hi16_list = NULL;
+		me->arch.r_mips_hi16_list = NULL;
 	}
 
 	/*
@@ -201,6 +209,9 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 	return 0;
 
 out_danger:
+	free_relocation_chain(l);
+	me->arch.r_mips_hi16_list = NULL;
+
 	pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
 
 	return -ENOEXEC;
@@ -273,6 +284,7 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
 	pr_debug("Applying relocate section %u to %u\n", relsec,
 	       sechdrs[relsec].sh_info);
 
+	me->arch.r_mips_hi16_list = NULL;
 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 		/* This is where to make the change */
 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
@@ -296,6 +308,19 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
 			return res;
 	}
 
+	/*
+	 * Normally the hi16 list should be deallocated at this point.  A
+	 * malformed binary however could contain a series of R_MIPS_HI16
+	 * relocations not followed by a R_MIPS_LO16 relocation.  In that
+	 * case, free up the list and return an error.
+	 */
+	if (me->arch.r_mips_hi16_list) {
+		free_relocation_chain(me->arch.r_mips_hi16_list);
+		me->arch.r_mips_hi16_list = NULL;
+
+		return -ENOEXEC;
+	}
+
 	return 0;
 }