[Xen-changelog] [xen master] livepatch: Include sizes when an mismatch occurs

[patchbot@xxxxxxx]

commit 7597fabca76e78aa8a6bf88db46692d162691234
Author:     Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
AuthorDate: Tue Jun 20 10:55:12 2017 -0400
Commit:     Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CommitDate: Thu Oct 5 09:27:32 2017 -0400

    livepatch: Include sizes when an mismatch occurs
    
    If the .bug.frames.X or .livepatch.funcs sizes are different
    than what the hypervisor expects - we fail the payload. To help
    in diagnosing this include the expected and the payload
    sizes.
    
    Also make it more natural by having "Multiples" in the warning.
    
    Also fix one case where we would fail if the size of the .ex_table
    was being zero - but that is OK.
    
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 xen/common/livepatch.c       | 46 +++++++++++++++++++++-----------------------
 xen/include/xen/elfstructs.h |  2 ++
 2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index 66167a5..0393829 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -457,6 +457,22 @@ static int secure_payload(struct payload *payload, struct 
livepatch_elf *elf)
     return rc;
 }
 
+static bool section_ok(const struct livepatch_elf *elf,
+                       const struct livepatch_elf_sec *sec, size_t sz)
+{
+    if ( !elf || !sec )
+        return false;
+
+    if ( sec->sec->sh_size % sz )
+    {
+        dprintk(XENLOG_ERR, LIVEPATCH "%s: Wrong size %"PRIuElfWord" of %s 
(must be multiple of %zu)\n",
+                elf->name, sec->sec->sh_size, sec->name, sz);
+        return false;
+    }
+
+    return true;
+}
+
 static int check_special_sections(const struct livepatch_elf *elf)
 {
     unsigned int i;
@@ -506,12 +522,8 @@ static int prepare_payload(struct payload *payload,
 
     sec = livepatch_elf_sec_by_name(elf, ELF_LIVEPATCH_FUNC);
     ASSERT(sec);
-    if ( sec->sec->sh_size % sizeof(*payload->funcs) )
-    {
-        dprintk(XENLOG_ERR, LIVEPATCH "%s: Wrong size of 
"ELF_LIVEPATCH_FUNC"!\n",
-                elf->name);
+    if ( !section_ok(elf, sec, sizeof(*payload->funcs)) )
         return -EINVAL;
-    }
 
     payload->funcs = sec->load_addr;
     payload->nfuncs = sec->sec->sh_size / sizeof(*payload->funcs);
@@ -553,7 +565,7 @@ static int prepare_payload(struct payload *payload,
     sec = livepatch_elf_sec_by_name(elf, ".livepatch.hooks.load");
     if ( sec )
     {
-        if ( sec->sec->sh_size % sizeof(*payload->load_funcs) )
+        if ( !section_ok(elf, sec, sizeof(*payload->load_funcs)) )
             return -EINVAL;
 
         payload->load_funcs = sec->load_addr;
@@ -563,7 +575,7 @@ static int prepare_payload(struct payload *payload,
     sec = livepatch_elf_sec_by_name(elf, ".livepatch.hooks.unload");
     if ( sec )
     {
-        if ( sec->sec->sh_size % sizeof(*payload->unload_funcs) )
+        if ( !section_ok(elf, sec, sizeof(*payload->unload_funcs)) )
             return -EINVAL;
 
         payload->unload_funcs = sec->load_addr;
@@ -634,12 +646,8 @@ static int prepare_payload(struct payload *payload,
         if ( !sec )
             continue;
 
-        if ( sec->sec->sh_size % sizeof(*region->frame[i].bugs) )
-        {
-            dprintk(XENLOG_ERR, LIVEPATCH "%s: Wrong size of 
.bug_frames.%u!\n",
-                    elf->name, i);
+        if ( !section_ok(elf, sec, sizeof(*region->frame[i].bugs)) )
             return -EINVAL;
-        }
 
         region->frame[i].bugs = sec->load_addr;
         region->frame[i].n_bugs = sec->sec->sh_size /
@@ -652,12 +660,8 @@ static int prepare_payload(struct payload *payload,
 #ifdef CONFIG_HAS_ALTERNATIVE
         struct alt_instr *a, *start, *end;
 
-        if ( sec->sec->sh_size % sizeof(*a) )
-        {
-            dprintk(XENLOG_ERR, LIVEPATCH "%s: Size of .alt_instr is not 
multiple of %zu!\n",
-                    elf->name, sizeof(*a));
+        if ( !section_ok(elf, sec, sizeof(*a)) )
             return -EINVAL;
-        }
 
         start = sec->load_addr;
         end = sec->load_addr + sec->sec->sh_size;
@@ -689,14 +693,8 @@ static int prepare_payload(struct payload *payload,
 #ifdef CONFIG_HAS_EX_TABLE
         struct exception_table_entry *s, *e;
 
-        if ( !sec->sec->sh_size ||
-             (sec->sec->sh_size % sizeof(*region->ex)) )
-        {
-            dprintk(XENLOG_ERR, LIVEPATCH "%s: Wrong size of .ex_table 
(exp:%lu vs %lu)!\n",
-                    elf->name, sizeof(*region->ex),
-                    sec->sec->sh_size);
+        if ( !section_ok(elf, sec, sizeof(*region->ex)) )
             return -EINVAL;
-        }
 
         s = sec->load_addr;
         e = sec->load_addr + sec->sec->sh_size;
diff --git a/xen/include/xen/elfstructs.h b/xen/include/xen/elfstructs.h
index 950e149..726ca8f 100644
--- a/xen/include/xen/elfstructs.h
+++ b/xen/include/xen/elfstructs.h
@@ -555,6 +555,7 @@ typedef struct {
 
 #if defined(ELFSIZE) && (ELFSIZE == 32)
 #define PRIxElfAddr    "08x"
+#define PRIuElfWord    "8u"
 
 #define Elf_Ehdr       Elf32_Ehdr
 #define Elf_Phdr       Elf32_Phdr
@@ -582,6 +583,7 @@ typedef struct {
 #define AuxInfo                Aux32Info
 #elif defined(ELFSIZE) && (ELFSIZE == 64)
 #define PRIxElfAddr    PRIx64
+#define PRIuElfWord    PRIu64
 
 #define Elf_Ehdr       Elf64_Ehdr
 #define Elf_Phdr       Elf64_Phdr
--
generated by git-patchbot for /home/xen/git/xen.git#master

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