1 files changed, 213 insertions, 256 deletions

diff --git a/updater/blockimg.cpp b/updater/blockimg.cpp
index a80180a9a..4dadceb5e 100644
--- a/updater/blockimg.cpp
+++ b/updater/blockimg.cpp
@@ -18,7 +18,6 @@
 #include <errno.h>
 #include <dirent.h>
 #include <fcntl.h>
-#include <inttypes.h>
 #include <linux/fs.h>
 #include <pthread.h>
 #include <stdarg.h>
@@ -33,26 +32,27 @@
 #include <unistd.h>
 #include <fec/io.h>
 
-#include <map>
 #include <memory>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
+#include <android-base/logging.h>
 #include <android-base/parseint.h>
 #include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <ziparchive/zip_archive.h>
 
 #include "applypatch/applypatch.h"
 #include "edify/expr.h"
 #include "error_code.h"
-#include "install.h"
+#include "updater/install.h"
 #include "openssl/sha.h"
-#include "minzip/Hash.h"
 #include "ota_io.h"
 #include "print_sha1.h"
-#include "unique_fd.h"
-#include "updater.h"
+#include "updater/updater.h"
 
-#define BLOCKSIZE 4096
+static constexpr size_t BLOCKSIZE = 4096;
 
 // Set this to 0 to interpret 'erase' transfers to mean do a
 // BLKDISCARD ioctl (the normal behavior).  Set to 1 to interpret
@@ -71,7 +71,7 @@ struct RangeSet {
 
 static CauseCode failure_type = kNoCause;
 static bool is_retry = false;
-static std::map<std::string, RangeSet> stash_map;
+static std::unordered_map<std::string, RangeSet> stash_map;
 
 static void parse_range(const std::string& range_text, RangeSet& rs) {
 
@@ -121,7 +121,7 @@ static void parse_range(const std::string& range_text, RangeSet& rs) {
     return;
 
 err:
-    fprintf(stderr, "failed to parse range '%s'\n", range_text.c_str());
+    LOG(ERROR) << "failed to parse range '" << range_text << "'";
     exit(1);
 }
 
@@ -149,7 +149,11 @@ static int read_all(int fd, uint8_t* data, size_t size) {
         ssize_t r = TEMP_FAILURE_RETRY(ota_read(fd, data+so_far, size-so_far));
         if (r == -1) {
             failure_type = kFreadFailure;
-            fprintf(stderr, "read failed: %s\n", strerror(errno));
+            PLOG(ERROR) << "read failed";
+            return -1;
+        } else if (r == 0) {
+            failure_type = kFreadFailure;
+            LOG(ERROR) << "read reached unexpected EOF.";
             return -1;
         }
         so_far += r;
@@ -167,7 +171,7 @@ static int write_all(int fd, const uint8_t* data, size_t size) {
         ssize_t w = TEMP_FAILURE_RETRY(ota_write(fd, data+written, size-written));
         if (w == -1) {
             failure_type = kFwriteFailure;
-            fprintf(stderr, "write failed: %s\n", strerror(errno));
+            PLOG(ERROR) << "write failed";
             return -1;
         }
         written += w;
@@ -189,7 +193,7 @@ static bool discard_blocks(int fd, off64_t offset, uint64_t size) {
     uint64_t args[2] = {static_cast<uint64_t>(offset), size};
     int status = ioctl(fd, BLKDISCARD, &args);
     if (status == -1) {
-        fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
+        PLOG(ERROR) << "BLKDISCARD ioctl failed";
         return false;
     }
     return true;
@@ -199,7 +203,7 @@ static bool check_lseek(int fd, off64_t offset, int whence) {
     off64_t rc = TEMP_FAILURE_RETRY(lseek64(fd, offset, whence));
     if (rc == -1) {
         failure_type = kLseekFailure;
-        fprintf(stderr, "lseek64 failed: %s\n", strerror(errno));
+        PLOG(ERROR) << "lseek64 failed";
         return false;
     }
     return true;
@@ -213,7 +217,7 @@ static void allocate(size_t size, std::vector<uint8_t>& buffer) {
 }
 
 struct RangeSinkState {
-    RangeSinkState(RangeSet& rs) : tgt(rs) { };
+    explicit RangeSinkState(RangeSet& rs) : tgt(rs) { };
 
     int fd;
     const RangeSet& tgt;
@@ -225,7 +229,7 @@ static ssize_t RangeSinkWrite(const uint8_t* data, ssize_t size, void* token) {
     RangeSinkState* rss = reinterpret_cast<RangeSinkState*>(token);
 
     if (rss->p_remain == 0) {
-        fprintf(stderr, "range sink write overrun");
+        LOG(ERROR) << "range sink write overrun";
         return 0;
     }
 
@@ -296,8 +300,8 @@ static ssize_t RangeSinkWrite(const uint8_t* data, ssize_t size, void* token) {
 // rss and signals the condition again.
 
 struct NewThreadInfo {
-    ZipArchive* za;
-    const ZipEntry* entry;
+    ZipArchiveHandle za;
+    ZipEntry entry;
 
     RangeSinkState* rss;
 
@@ -305,7 +309,7 @@ struct NewThreadInfo {
     pthread_cond_t cv;
 };
 
-static bool receive_new_data(const unsigned char* data, int size, void* cookie) {
+static bool receive_new_data(const uint8_t* data, size_t size, void* cookie) {
     NewThreadInfo* nti = reinterpret_cast<NewThreadInfo*>(cookie);
 
     while (size > 0) {
@@ -338,7 +342,7 @@ static bool receive_new_data(const unsigned char* data, int size, void* cookie)
 
 static void* unzip_new_data(void* cookie) {
     NewThreadInfo* nti = (NewThreadInfo*) cookie;
-    mzProcessZipEntryContents(nti->za, nti->entry, receive_new_data, nti);
+    ProcessZipEntryContents(nti->za, &nti->entry, receive_new_data, nti);
     return nullptr;
 }
 
@@ -398,7 +402,7 @@ struct CommandParameters {
     std::string stashbase;
     bool canwrite;
     int createdstash;
-    int fd;
+    android::base::unique_fd fd;
     bool foundwrites;
     bool isunresumable;
     int version;
@@ -422,7 +426,7 @@ static int LoadSrcTgtVersion1(CommandParameters& params, RangeSet& tgt, size_t&
         std::vector<uint8_t>& buffer, int fd) {
 
     if (params.cpos + 1 >= params.tokens.size()) {
-        fprintf(stderr, "invalid parameters\n");
+        LOG(ERROR) << "invalid parameters";
         return -1;
     }
 
@@ -451,8 +455,8 @@ static int VerifyBlocks(const std::string& expected, const std::vector<uint8_t>&
 
     if (hexdigest != expected) {
         if (printerror) {
-            fprintf(stderr, "failed to verify blocks (expected %s, read %s)\n",
-                    expected.c_str(), hexdigest.c_str());
+            LOG(ERROR) << "failed to verify blocks (expected " << expected << ", read "
+                       << hexdigest << ")";
         }
         return -1;
     }
@@ -488,7 +492,7 @@ static void EnumerateStash(const std::string& dirname, StashCallback callback, v
 
     if (directory == nullptr) {
         if (errno != ENOENT) {
-            fprintf(stderr, "opendir \"%s\" failed: %s\n", dirname.c_str(), strerror(errno));
+            PLOG(ERROR) << "opendir \"" << dirname << "\" failed";
         }
         return;
     }
@@ -511,7 +515,7 @@ static void UpdateFileSize(const std::string& fn, void* data) {
 
     struct stat sb;
     if (stat(fn.c_str(), &sb) == -1) {
-        fprintf(stderr, "stat \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        PLOG(ERROR) << "stat \"" << fn << "\" failed";
         return;
     }
 
@@ -525,10 +529,10 @@ static void UpdateFileSize(const std::string& fn, void* data) {
 
 static void DeleteFile(const std::string& fn, void* /* data */) {
     if (!fn.empty()) {
-        fprintf(stderr, "deleting %s\n", fn.c_str());
+        LOG(INFO) << "deleting " << fn;
 
         if (unlink(fn.c_str()) == -1 && errno != ENOENT) {
-            fprintf(stderr, "unlink \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+            PLOG(ERROR) << "unlink \"" << fn << "\" failed";
         }
     }
 }
@@ -544,14 +548,14 @@ static void DeleteStash(const std::string& base) {
         return;
     }
 
-    fprintf(stderr, "deleting stash %s\n", base.c_str());
+    LOG(INFO) << "deleting stash " << base;
 
     std::string dirname = GetStashFileName(base, "", "");
     EnumerateStash(dirname, DeleteFile, nullptr);
 
     if (rmdir(dirname.c_str()) == -1) {
         if (errno != ENOENT && errno != ENOTDIR) {
-            fprintf(stderr, "rmdir \"%s\" failed: %s\n", dirname.c_str(), strerror(errno));
+            PLOG(ERROR) << "rmdir \"" << dirname << "\" failed";
         }
     }
 }
@@ -567,11 +571,11 @@ static int LoadStash(CommandParameters& params, const std::string& base, const s
             allocate(src.size * BLOCKSIZE, buffer);
 
             if (ReadBlocks(src, buffer, params.fd) == -1) {
-                fprintf(stderr, "failed to read source blocks in stash map.\n");
+                LOG(ERROR) << "failed to read source blocks in stash map.";
                 return -1;
             }
             if (VerifyBlocks(id, buffer, src.size, true) != 0) {
-                fprintf(stderr, "failed to verify loaded source blocks in stash map.\n");
+                LOG(ERROR) << "failed to verify loaded source blocks in stash map.";
                 return -1;
             }
             return 0;
@@ -595,24 +599,21 @@ static int LoadStash(CommandParameters& params, const std::string& base, const s
 
     if (res == -1) {
         if (errno != ENOENT || printnoent) {
-            fprintf(stderr, "stat \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+            PLOG(ERROR) << "stat \"" << fn << "\" failed";
         }
         return -1;
     }
 
-    fprintf(stderr, " loading %s\n", fn.c_str());
+    LOG(INFO) << " loading " << fn;
 
     if ((sb.st_size % BLOCKSIZE) != 0) {
-        fprintf(stderr, "%s size %" PRId64 " not multiple of block size %d",
-                fn.c_str(), static_cast<int64_t>(sb.st_size), BLOCKSIZE);
+        LOG(ERROR) << fn << " size " << sb.st_size << " not multiple of block size " << BLOCKSIZE;
         return -1;
     }
 
-    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_RDONLY));
-    unique_fd fd_holder(fd);
-
+    android::base::unique_fd fd(TEMP_FAILURE_RETRY(ota_open(fn.c_str(), O_RDONLY)));
     if (fd == -1) {
-        fprintf(stderr, "open \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        PLOG(ERROR) << "open \"" << fn << "\" failed";
         return -1;
     }
 
@@ -625,7 +626,7 @@ static int LoadStash(CommandParameters& params, const std::string& base, const s
     *blocks = sb.st_size / BLOCKSIZE;
 
     if (verify && VerifyBlocks(id, buffer, *blocks, true) != 0) {
-        fprintf(stderr, "unexpected contents in %s\n", fn.c_str());
+        LOG(ERROR) << "unexpected contents in " << fn;
         DeleteFile(fn, nullptr);
         return -1;
     }
@@ -640,7 +641,7 @@ static int WriteStash(const std::string& base, const std::string& id, int blocks
     }
 
     if (checkspace && CacheSizeCheck(blocks * BLOCKSIZE) != 0) {
-        fprintf(stderr, "not enough space to write stash\n");
+        LOG(ERROR) << "not enough space to write stash";
         return -1;
     }
 
@@ -655,7 +656,7 @@ static int WriteStash(const std::string& base, const std::string& id, int blocks
             // The file already exists and since the name is the hash of the contents,
             // it's safe to assume the contents are identical (accidental hash collisions
             // are unlikely)
-            fprintf(stderr, " skipping %d existing blocks in %s\n", blocks, cn.c_str());
+            LOG(INFO) << " skipping " << blocks << " existing blocks in " << cn;
             *exists = true;
             return 0;
         }
@@ -663,13 +664,12 @@ static int WriteStash(const std::string& base, const std::string& id, int blocks
         *exists = false;
     }
 
-    fprintf(stderr, " writing %d blocks to %s\n", blocks, cn.c_str());
-
-    int fd = TEMP_FAILURE_RETRY(open(fn.c_str(), O_WRONLY | O_CREAT | O_TRUNC, STASH_FILE_MODE));
-    unique_fd fd_holder(fd);
+    LOG(INFO) << " writing " << blocks << " blocks to " << cn;
 
+    android::base::unique_fd fd(
+        TEMP_FAILURE_RETRY(ota_open(fn.c_str(), O_WRONLY | O_CREAT | O_TRUNC, STASH_FILE_MODE)));
     if (fd == -1) {
-        fprintf(stderr, "failed to create \"%s\": %s\n", fn.c_str(), strerror(errno));
+        PLOG(ERROR) << "failed to create \"" << fn << "\"";
         return -1;
     }
 
@@ -679,29 +679,27 @@ static int WriteStash(const std::string& base, const std::string& id, int blocks
 
     if (ota_fsync(fd) == -1) {
         failure_type = kFsyncFailure;
-        fprintf(stderr, "fsync \"%s\" failed: %s\n", fn.c_str(), strerror(errno));
+        PLOG(ERROR) << "fsync \"" << fn << "\" failed";
         return -1;
     }
 
     if (rename(fn.c_str(), cn.c_str()) == -1) {
-        fprintf(stderr, "rename(\"%s\", \"%s\") failed: %s\n", fn.c_str(), cn.c_str(),
-                strerror(errno));
+        PLOG(ERROR) << "rename(\"" << fn << "\", \"" << cn << "\") failed";
         return -1;
     }
 
     std::string dname = GetStashFileName(base, "", "");
-    int dfd = TEMP_FAILURE_RETRY(open(dname.c_str(), O_RDONLY | O_DIRECTORY));
-    unique_fd dfd_holder(dfd);
-
+    android::base::unique_fd dfd(TEMP_FAILURE_RETRY(ota_open(dname.c_str(),
+                                                             O_RDONLY | O_DIRECTORY)));
     if (dfd == -1) {
         failure_type = kFileOpenFailure;
-        fprintf(stderr, "failed to open \"%s\" failed: %s\n", dname.c_str(), strerror(errno));
+        PLOG(ERROR) << "failed to open \"" << dname << "\" failed";
         return -1;
     }
 
     if (ota_fsync(dfd) == -1) {
         failure_type = kFsyncFailure;
-        fprintf(stderr, "fsync \"%s\" failed: %s\n", dname.c_str(), strerror(errno));
+        PLOG(ERROR) << "fsync \"" << dname << "\" failed";
         return -1;
     }
 
@@ -733,7 +731,7 @@ static int CreateStash(State* state, int maxblocks, const char* blockdev, std::s
                    dirname.c_str(), strerror(errno));
         return -1;
     } else if (res != 0) {
-        fprintf(stderr, "creating stash %s\n", dirname.c_str());
+        LOG(INFO) << "creating stash " << dirname;
         res = mkdir(dirname.c_str(), STASH_DIRECTORY_MODE);
 
         if (res != 0) {
@@ -750,7 +748,7 @@ static int CreateStash(State* state, int maxblocks, const char* blockdev, std::s
         return 1;  // Created directory
     }
 
-    fprintf(stderr, "using existing stash %s\n", dirname.c_str());
+    LOG(INFO) << "using existing stash " << dirname;
 
     // If the directory already exists, calculate the space already allocated to
     // stash files and check if there's enough for all required blocks. Delete any
@@ -776,7 +774,7 @@ static int SaveStash(CommandParameters& params, const std::string& base,
 
     // <stash_id> <src_range>
     if (params.cpos + 1 >= params.tokens.size()) {
-        fprintf(stderr, "missing id and/or src range fields in stash command\n");
+        LOG(ERROR) << "missing id and/or src range fields in stash command";
         return -1;
     }
     const std::string& id = params.tokens[params.cpos++];
@@ -803,7 +801,7 @@ static int SaveStash(CommandParameters& params, const std::string& base,
         // data later, this is an unrecoverable error. However, the command
         // that uses the data may have already completed previously, so the
         // possible failure will occur during source block verification.
-        fprintf(stderr, "failed to load source blocks for stash %s\n", id.c_str());
+        LOG(ERROR) << "failed to load source blocks for stash " << id;
         return 0;
     }
 
@@ -813,7 +811,7 @@ static int SaveStash(CommandParameters& params, const std::string& base,
         return 0;
     }
 
-    fprintf(stderr, "stashing %zu blocks to %s\n", blocks, id.c_str());
+    LOG(INFO) << "stashing " << blocks << " blocks to " << id;
     params.stashed += blocks;
     return WriteStash(base, id, blocks, buffer, false, nullptr);
 }
@@ -869,7 +867,7 @@ static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t&
     // At least it needs to provide three parameters: <tgt_range>,
     // <src_block_count> and "-"/<src_range>.
     if (params.cpos + 2 >= params.tokens.size()) {
-        fprintf(stderr, "invalid parameters\n");
+        LOG(ERROR) << "invalid parameters";
         return -1;
     }
 
@@ -879,7 +877,7 @@ static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t&
     // <src_block_count>
     const std::string& token = params.tokens[params.cpos++];
     if (!android::base::ParseUint(token.c_str(), &src_blocks)) {
-        fprintf(stderr, "invalid src_block_count \"%s\"\n", token.c_str());
+        LOG(ERROR) << "invalid src_block_count \"" << token << "\"";
         return -1;
     }
 
@@ -919,7 +917,7 @@ static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t&
         // stashed data should go.
         std::vector<std::string> tokens = android::base::Split(params.tokens[params.cpos++], ":");
         if (tokens.size() != 2) {
-            fprintf(stderr, "invalid parameter\n");
+            LOG(ERROR) << "invalid parameter";
             return -1;
         }
 
@@ -929,7 +927,7 @@ static int LoadSrcTgtVersion2(CommandParameters& params, RangeSet& tgt, size_t&
         if (res == -1) {
             // These source blocks will fail verification if used later, but we
             // will let the caller decide if this is a fatal failure
-            fprintf(stderr, "failed to load stash %s\n", tokens[0].c_str());
+            LOG(ERROR) << "failed to load stash " << tokens[0];
             continue;
         }
 
@@ -963,7 +961,7 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
         bool onehash, bool& overlap) {
 
     if (params.cpos >= params.tokens.size()) {
-        fprintf(stderr, "missing source hash\n");
+        LOG(ERROR) << "missing source hash";
         return -1;
     }
 
@@ -974,14 +972,14 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
         tgthash = srchash;
     } else {
         if (params.cpos >= params.tokens.size()) {
-            fprintf(stderr, "missing target hash\n");
+            LOG(ERROR) << "missing target hash";
             return -1;
         }
         tgthash = params.tokens[params.cpos++];
     }
 
-    if (LoadSrcTgtVersion2(params, tgt, src_blocks, params.buffer, params.fd, params.stashbase,
-            &overlap) == -1) {
+    if (LoadSrcTgtVersion2(params, tgt, src_blocks, params.buffer, params.fd,
+                           params.stashbase, &overlap) == -1) {
         return -1;
     }
 
@@ -1001,13 +999,12 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
         // resume from possible write errors. In verify mode, we can skip stashing
         // because the source blocks won't be overwritten.
         if (overlap && params.canwrite) {
-            fprintf(stderr, "stashing %zu overlapping blocks to %s\n", src_blocks,
-                    srchash.c_str());
+            LOG(INFO) << "stashing " << src_blocks << " overlapping blocks to " << srchash;
 
             bool stash_exists = false;
             if (WriteStash(params.stashbase, srchash, src_blocks, params.buffer, true,
                            &stash_exists) != 0) {
-                fprintf(stderr, "failed to stash overlapping source blocks\n");
+                LOG(ERROR) << "failed to stash overlapping source blocks";
                 return -1;
             }
 
@@ -1031,7 +1028,7 @@ static int LoadSrcTgtVersion3(CommandParameters& params, RangeSet& tgt, size_t&
     }
 
     // Valid source data not available, update cannot be resumed
-    fprintf(stderr, "partition has unexpected contents\n");
+    LOG(ERROR) << "partition has unexpected contents";
     params.isunresumable = true;
 
     return -1;
@@ -1053,25 +1050,25 @@ static int PerformCommandMove(CommandParameters& params) {
     }
 
     if (status == -1) {
-        fprintf(stderr, "failed to read blocks for move\n");
+        LOG(ERROR) << "failed to read blocks for move";
         return -1;
     }
 
     if (status == 0) {
         params.foundwrites = true;
     } else if (params.foundwrites) {
-        fprintf(stderr, "warning: commands executed out of order [%s]\n", params.cmdname);
+        LOG(WARNING) << "warning: commands executed out of order [" << params.cmdname << "]";
     }
 
     if (params.canwrite) {
         if (status == 0) {
-            fprintf(stderr, "  moving %zu blocks\n", blocks);
+            LOG(INFO) << "  moving " << blocks << " blocks";
 
             if (WriteBlocks(tgt, params.buffer, params.fd) == -1) {
                 return -1;
             }
         } else {
-            fprintf(stderr, "skipping %zu already moved blocks\n", blocks);
+            LOG(INFO) << "skipping " << blocks << " already moved blocks";
         }
 
     }
@@ -1094,7 +1091,7 @@ static int PerformCommandStash(CommandParameters& params) {
 static int PerformCommandFree(CommandParameters& params) {
     // <stash_id>
     if (params.cpos >= params.tokens.size()) {
-        fprintf(stderr, "missing stash id in free command\n");
+        LOG(ERROR) << "missing stash id in free command";
         return -1;
     }
 
@@ -1115,14 +1112,14 @@ static int PerformCommandFree(CommandParameters& params) {
 static int PerformCommandZero(CommandParameters& params) {
 
     if (params.cpos >= params.tokens.size()) {
-        fprintf(stderr, "missing target blocks for zero\n");
+        LOG(ERROR) << "missing target blocks for zero";
         return -1;
     }
 
     RangeSet tgt;
     parse_range(params.tokens[params.cpos++], tgt);
 
-    fprintf(stderr, "  zeroing %zu blocks\n", tgt.size);
+    LOG(INFO) << "  zeroing " << tgt.size << " blocks";
 
     allocate(BLOCKSIZE, params.buffer);
     memset(params.buffer.data(), 0, BLOCKSIZE);
@@ -1159,7 +1156,7 @@ static int PerformCommandZero(CommandParameters& params) {
 static int PerformCommandNew(CommandParameters& params) {
 
     if (params.cpos >= params.tokens.size()) {
-        fprintf(stderr, "missing target blocks for new\n");
+        LOG(ERROR) << "missing target blocks for new";
         return -1;
     }
 
@@ -1167,7 +1164,7 @@ static int PerformCommandNew(CommandParameters& params) {
     parse_range(params.tokens[params.cpos++], tgt);
 
     if (params.canwrite) {
-        fprintf(stderr, " writing %zu blocks of new data\n", tgt.size);
+        LOG(INFO) << " writing " << tgt.size << " blocks of new data";
 
         RangeSinkState rss(tgt);
         rss.fd = params.fd;
@@ -1203,19 +1200,19 @@ static int PerformCommandDiff(CommandParameters& params) {
 
     // <offset> <length>
     if (params.cpos + 1 >= params.tokens.size()) {
-        fprintf(stderr, "missing patch offset or length for %s\n", params.cmdname);
+        LOG(ERROR) << "missing patch offset or length for " << params.cmdname;
         return -1;
     }
 
     size_t offset;
     if (!android::base::ParseUint(params.tokens[params.cpos++].c_str(), &offset)) {
-        fprintf(stderr, "invalid patch offset\n");
+        LOG(ERROR) << "invalid patch offset";
         return -1;
     }
 
     size_t len;
     if (!android::base::ParseUint(params.tokens[params.cpos++].c_str(), &len)) {
-        fprintf(stderr, "invalid patch offset\n");
+        LOG(ERROR) << "invalid patch len";
         return -1;
     }
 
@@ -1233,24 +1230,22 @@ static int PerformCommandDiff(CommandParameters& params) {
     }
 
     if (status == -1) {
-        fprintf(stderr, "failed to read blocks for diff\n");
+        LOG(ERROR) << "failed to read blocks for diff";
         return -1;
     }
 
     if (status == 0) {
         params.foundwrites = true;
     } else if (params.foundwrites) {
-        fprintf(stderr, "warning: commands executed out of order [%s]\n", params.cmdname);
+        LOG(WARNING) << "warning: commands executed out of order [" << params.cmdname << "]";
     }
 
     if (params.canwrite) {
         if (status == 0) {
-            fprintf(stderr, "patching %zu blocks to %zu\n", blocks, tgt.size);
+            LOG(INFO) << "patching " << blocks << " blocks to " << tgt.size;
 
-            Value patch_value;
-            patch_value.type = VAL_BLOB;
-            patch_value.size = len;
-            patch_value.data = (char*) (params.patch_start + offset);
+            Value patch_value(VAL_BLOB,
+                    std::string(reinterpret_cast<const char*>(params.patch_start + offset), len));
 
             RangeSinkState rss(tgt);
             rss.fd = params.fd;
@@ -1269,24 +1264,24 @@ static int PerformCommandDiff(CommandParameters& params) {
             if (params.cmdname[0] == 'i') {      // imgdiff
                 if (ApplyImagePatch(params.buffer.data(), blocks * BLOCKSIZE, &patch_value,
                         &RangeSinkWrite, &rss, nullptr, nullptr) != 0) {
-                    fprintf(stderr, "Failed to apply image patch.\n");
+                    LOG(ERROR) << "Failed to apply image patch.";
                     return -1;
                 }
             } else {
                 if (ApplyBSDiffPatch(params.buffer.data(), blocks * BLOCKSIZE, &patch_value,
                         0, &RangeSinkWrite, &rss, nullptr) != 0) {
-                    fprintf(stderr, "Failed to apply bsdiff patch.\n");
+                    LOG(ERROR) << "Failed to apply bsdiff patch.";
                     return -1;
                 }
             }
 
             // We expect the output of the patcher to fill the tgt ranges exactly.
             if (rss.p_block != tgt.count || rss.p_remain != 0) {
-                fprintf(stderr, "range sink underrun?\n");
+                LOG(ERROR) << "range sink underrun?";
             }
         } else {
-            fprintf(stderr, "skipping %zu blocks already patched to %zu [%s]\n",
-                blocks, tgt.size, params.cmdline);
+            LOG(INFO) << "skipping " << blocks << " blocks already patched to " << tgt.size
+                      << " [" << params.cmdline << "]";
         }
     }
 
@@ -1307,17 +1302,17 @@ static int PerformCommandErase(CommandParameters& params) {
 
     struct stat sb;
     if (fstat(params.fd, &sb) == -1) {
-        fprintf(stderr, "failed to fstat device to erase: %s\n", strerror(errno));
+        PLOG(ERROR) << "failed to fstat device to erase";
         return -1;
     }
 
     if (!S_ISBLK(sb.st_mode)) {
-        fprintf(stderr, "not a block device; skipping erase\n");
+        LOG(ERROR) << "not a block device; skipping erase";
         return -1;
     }
 
     if (params.cpos >= params.tokens.size()) {
-        fprintf(stderr, "missing target blocks for erase\n");
+        LOG(ERROR) << "missing target blocks for erase";
         return -1;
     }
 
@@ -1325,7 +1320,7 @@ static int PerformCommandErase(CommandParameters& params) {
     parse_range(params.tokens[params.cpos++], tgt);
 
     if (params.canwrite) {
-        fprintf(stderr, " erasing %zu blocks\n", tgt.size);
+        LOG(INFO) << " erasing " << tgt.size << " blocks";
 
         for (size_t i = 0; i < tgt.count; ++i) {
             uint64_t blocks[2];
@@ -1335,7 +1330,7 @@ static int PerformCommandErase(CommandParameters& params) {
             blocks[1] = (tgt.pos[i * 2 + 1] - tgt.pos[i * 2]) * (uint64_t) BLOCKSIZE;
 
             if (ioctl(params.fd, BLKDISCARD, &blocks) == -1) {
-                fprintf(stderr, "BLKDISCARD ioctl failed: %s\n", strerror(errno));
+                PLOG(ERROR) << "BLKDISCARD ioctl failed";
                 return -1;
             }
         }
@@ -1352,28 +1347,6 @@ struct Command {
     CommandFunction f;
 };
 
-// CompareCommands and CompareCommandNames are for the hash table
-
-static int CompareCommands(const void* c1, const void* c2) {
-    return strcmp(((const Command*) c1)->name, ((const Command*) c2)->name);
-}
-
-static int CompareCommandNames(const void* c1, const void* c2) {
-    return strcmp(((const Command*) c1)->name, (const char*) c2);
-}
-
-// HashString is used to hash command names for the hash table
-
-static unsigned int HashString(const char *s) {
-    unsigned int hash = 0;
-    if (s) {
-        while (*s) {
-            hash = hash * 33 + *s++;
-        }
-    }
-    return hash;
-}
-
 // args:
 //    - block device (or file) to modify in-place
 //    - transfer list (blob)
@@ -1382,82 +1355,76 @@ static unsigned int HashString(const char *s) {
 
 static Value* PerformBlockImageUpdate(const char* name, State* state, int /* argc */, Expr* argv[],
         const Command* commands, size_t cmdcount, bool dryrun) {
-    CommandParameters params;
-    memset(&params, 0, sizeof(params));
+    CommandParameters params = {};
     params.canwrite = !dryrun;
 
-    fprintf(stderr, "performing %s\n", dryrun ? "verification" : "update");
+    LOG(INFO) << "performing " << (dryrun ? "verification" : "update");
     if (state->is_retry) {
         is_retry = true;
-        fprintf(stderr, "This update is a retry.\n");
+        LOG(INFO) << "This update is a retry.";
     }
 
-    Value* blockdev_filename = nullptr;
-    Value* transfer_list_value = nullptr;
-    Value* new_data_fn = nullptr;
-    Value* patch_data_fn = nullptr;
-    if (ReadValueArgs(state, argv, 4, &blockdev_filename, &transfer_list_value,
-            &new_data_fn, &patch_data_fn) < 0) {
-        return StringValue(strdup(""));
+    std::vector<std::unique_ptr<Value>> args;
+    if (!ReadValueArgs(state, 4, argv, &args)) {
+        return nullptr;
     }
-    std::unique_ptr<Value, decltype(&FreeValue)> blockdev_filename_holder(blockdev_filename,
-            FreeValue);
-    std::unique_ptr<Value, decltype(&FreeValue)> transfer_list_value_holder(transfer_list_value,
-            FreeValue);
-    std::unique_ptr<Value, decltype(&FreeValue)> new_data_fn_holder(new_data_fn, FreeValue);
-    std::unique_ptr<Value, decltype(&FreeValue)> patch_data_fn_holder(patch_data_fn, FreeValue);
+
+    const Value* blockdev_filename = args[0].get();
+    const Value* transfer_list_value = args[1].get();
+    const Value* new_data_fn = args[2].get();
+    const Value* patch_data_fn = args[3].get();
 
     if (blockdev_filename->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "blockdev_filename argument to %s must be string",
                    name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
     if (transfer_list_value->type != VAL_BLOB) {
         ErrorAbort(state, kArgsParsingFailure, "transfer_list argument to %s must be blob", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
     if (new_data_fn->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "new_data_fn argument to %s must be string", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
     if (patch_data_fn->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "patch_data_fn argument to %s must be string",
                    name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     UpdaterInfo* ui = reinterpret_cast<UpdaterInfo*>(state->cookie);
 
     if (ui == nullptr) {
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     FILE* cmd_pipe = ui->cmd_pipe;
-    ZipArchive* za = ui->package_zip;
+    ZipArchiveHandle za = ui->package_zip;
 
     if (cmd_pipe == nullptr || za == nullptr) {
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
-    const ZipEntry* patch_entry = mzFindZipEntry(za, patch_data_fn->data);
-    if (patch_entry == nullptr) {
-        fprintf(stderr, "%s(): no file \"%s\" in package", name, patch_data_fn->data);
-        return StringValue(strdup(""));
+    ZipString path_data(patch_data_fn->data.c_str());
+    ZipEntry patch_entry;
+    if (FindEntry(za, path_data, &patch_entry) != 0) {
+        LOG(ERROR) << name << "(): no file \"" << patch_data_fn->data << "\" in package";
+        return StringValue("");
     }
 
-    params.patch_start = ui->package_zip_addr + mzGetZipEntryOffset(patch_entry);
-    const ZipEntry* new_entry = mzFindZipEntry(za, new_data_fn->data);
-    if (new_entry == nullptr) {
-        fprintf(stderr, "%s(): no file \"%s\" in package", name, new_data_fn->data);
-        return StringValue(strdup(""));
+    params.patch_start = ui->package_zip_addr + patch_entry.offset;
+    ZipString new_data(new_data_fn->data.c_str());
+    ZipEntry new_entry;
+    if (FindEntry(za, new_data, &new_entry) != 0) {
+        LOG(ERROR) << name << "(): no file \"" << new_data_fn->data << "\" in package";
+        return StringValue("");
     }
 
-    params.fd = TEMP_FAILURE_RETRY(open(blockdev_filename->data, O_RDWR));
-    unique_fd fd_holder(params.fd);
-
+    params.fd.reset(TEMP_FAILURE_RETRY(ota_open(blockdev_filename->data.c_str(), O_RDWR)));
     if (params.fd == -1) {
-        fprintf(stderr, "open \"%s\" failed: %s\n", blockdev_filename->data, strerror(errno));
-        return StringValue(strdup(""));
+        PLOG(ERROR) << "open \"" << blockdev_filename->data << "\" failed";
+        return StringValue("");
     }
 
     if (params.canwrite) {
@@ -1472,38 +1439,35 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
 
         int error = pthread_create(&params.thread, &attr, unzip_new_data, &params.nti);
         if (error != 0) {
-            fprintf(stderr, "pthread_create failed: %s\n", strerror(error));
-            return StringValue(strdup(""));
+            PLOG(ERROR) << "pthread_create failed";
+            return StringValue("");
         }
     }
 
-    // Copy all the lines in transfer_list_value into std::string for
-    // processing.
-    const std::string transfer_list(transfer_list_value->data, transfer_list_value->size);
-    std::vector<std::string> lines = android::base::Split(transfer_list, "\n");
+    std::vector<std::string> lines = android::base::Split(transfer_list_value->data, "\n");
     if (lines.size() < 2) {
         ErrorAbort(state, kArgsParsingFailure, "too few lines in the transfer list [%zd]\n",
                    lines.size());
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     // First line in transfer list is the version number
     if (!android::base::ParseInt(lines[0].c_str(), &params.version, 1, 4)) {
-        fprintf(stderr, "unexpected transfer list version [%s]\n", lines[0].c_str());
-        return StringValue(strdup(""));
+        LOG(ERROR) << "unexpected transfer list version [" << lines[0] << "]";
+        return StringValue("");
     }
 
-    fprintf(stderr, "blockimg version is %d\n", params.version);
+    LOG(INFO) << "blockimg version is " << params.version;
 
     // Second line in transfer list is the total number of blocks we expect to write
     int total_blocks;
     if (!android::base::ParseInt(lines[1].c_str(), &total_blocks, 0)) {
         ErrorAbort(state, kArgsParsingFailure, "unexpected block count [%s]\n", lines[1].c_str());
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     if (total_blocks == 0) {
-        return StringValue(strdup("t"));
+        return StringValue("t");
     }
 
     size_t start = 2;
@@ -1511,23 +1475,23 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
         if (lines.size() < 4) {
             ErrorAbort(state, kArgsParsingFailure, "too few lines in the transfer list [%zu]\n",
                        lines.size());
-            return StringValue(strdup(""));
+            return StringValue("");
         }
 
         // Third line is how many stash entries are needed simultaneously
-        fprintf(stderr, "maximum stash entries %s\n", lines[2].c_str());
+        LOG(INFO) << "maximum stash entries " << lines[2];
 
         // Fourth line is the maximum number of blocks that will be stashed simultaneously
         int stash_max_blocks;
         if (!android::base::ParseInt(lines[3].c_str(), &stash_max_blocks, 0)) {
             ErrorAbort(state, kArgsParsingFailure, "unexpected maximum stash blocks [%s]\n",
                        lines[3].c_str());
-            return StringValue(strdup(""));
+            return StringValue("");
         }
 
-        int res = CreateStash(state, stash_max_blocks, blockdev_filename->data, params.stashbase);
+        int res = CreateStash(state, stash_max_blocks, blockdev_filename->data.c_str(), params.stashbase);
         if (res == -1) {
-            return StringValue(strdup(""));
+            return StringValue("");
         }
 
         params.createdstash = res;
@@ -1535,13 +1499,15 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
         start += 2;
     }
 
-    // Build a hash table of the available commands
-    HashTable* cmdht = mzHashTableCreate(cmdcount, nullptr);
-    std::unique_ptr<HashTable, decltype(&mzHashTableFree)> cmdht_holder(cmdht, mzHashTableFree);
-
+    // Build a map of the available commands
+    std::unordered_map<std::string, const Command*> cmd_map;
     for (size_t i = 0; i < cmdcount; ++i) {
-        unsigned int cmdhash = HashString(commands[i].name);
-        mzHashTableLookup(cmdht, cmdhash, (void*) &commands[i], CompareCommands, true);
+        if (cmd_map.find(commands[i].name) != cmd_map.end()) {
+            LOG(ERROR) << "Error: command [" << commands[i].name
+                       << "] already exists in the cmd map.";
+            return StringValue(strdup(""));
+        }
+        cmd_map[commands[i].name] = &commands[i];
     }
 
     int rc = -1;
@@ -1558,25 +1524,22 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
         params.cmdname = params.tokens[params.cpos++].c_str();
         params.cmdline = line_str.c_str();
 
-        unsigned int cmdhash = HashString(params.cmdname);
-        const Command* cmd = reinterpret_cast<const Command*>(mzHashTableLookup(cmdht, cmdhash,
-                const_cast<char*>(params.cmdname), CompareCommandNames,
-                false));
-
-        if (cmd == nullptr) {
-            fprintf(stderr, "unexpected command [%s]\n", params.cmdname);
+        if (cmd_map.find(params.cmdname) == cmd_map.end()) {
+            LOG(ERROR) << "unexpected command [" << params.cmdname << "]";
             goto pbiudone;
         }
 
+        const Command* cmd = cmd_map[params.cmdname];
+
         if (cmd->f != nullptr && cmd->f(params) == -1) {
-            fprintf(stderr, "failed to execute command [%s]\n", line_str.c_str());
+            LOG(ERROR) << "failed to execute command [" << line_str << "]";
             goto pbiudone;
         }
 
         if (params.canwrite) {
             if (ota_fsync(params.fd) == -1) {
                 failure_type = kFsyncFailure;
-                fprintf(stderr, "fsync failed: %s\n", strerror(errno));
+                PLOG(ERROR) << "fsync failed";
                 goto pbiudone;
             }
             fprintf(cmd_pipe, "set_progress %.4f\n", (double) params.written / total_blocks);
@@ -1587,11 +1550,11 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
     if (params.canwrite) {
         pthread_join(params.thread, nullptr);
 
-        fprintf(stderr, "wrote %zu blocks; expected %d\n", params.written, total_blocks);
-        fprintf(stderr, "stashed %zu blocks\n", params.stashed);
-        fprintf(stderr, "max alloc needed was %zu\n", params.buffer.size());
+        LOG(INFO) << "wrote " << params.written << " blocks; expected " << total_blocks;
+        LOG(INFO) << "stashed " << params.stashed << " blocks";
+        LOG(INFO) << "max alloc needed was " << params.buffer.size();
 
-        const char* partition = strrchr(blockdev_filename->data, '/');
+        const char* partition = strrchr(blockdev_filename->data.c_str(), '/');
         if (partition != nullptr && *(partition+1) != 0) {
             fprintf(cmd_pipe, "log bytes_written_%s: %zu\n", partition + 1,
                     params.written * BLOCKSIZE);
@@ -1603,7 +1566,7 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
         // may contain blocks needed to complete the update later.
         DeleteStash(params.stashbase);
     } else {
-        fprintf(stderr, "verified partition contents; update may be resumed\n");
+        LOG(INFO) << "verified partition contents; update may be resumed";
     }
 
     rc = 0;
@@ -1611,9 +1574,9 @@ static Value* PerformBlockImageUpdate(const char* name, State* state, int /* arg
 pbiudone:
     if (ota_fsync(params.fd) == -1) {
         failure_type = kFsyncFailure;
-        fprintf(stderr, "fsync failed: %s\n", strerror(errno));
+        PLOG(ERROR) << "fsync failed";
     }
-    // params.fd will be automatically closed because of the fd_holder above.
+    // params.fd will be automatically closed because it's a unique_fd.
 
     // Only delete the stash if the update cannot be resumed, or it's
     // a verification run and we created the stash.
@@ -1625,7 +1588,7 @@ pbiudone:
         state->cause_code = failure_type;
     }
 
-    return StringValue(rc == 0 ? strdup("t") : strdup(""));
+    return StringValue(rc == 0 ? "t" : "");
 }
 
 // The transfer list is a text file containing commands to
@@ -1719,32 +1682,29 @@ Value* BlockImageUpdateFn(const char* name, State* state, int argc, Expr* argv[]
 }
 
 Value* RangeSha1Fn(const char* name, State* state, int /* argc */, Expr* argv[]) {
-    Value* blockdev_filename;
-    Value* ranges;
-
-    if (ReadValueArgs(state, argv, 2, &blockdev_filename, &ranges) < 0) {
-        return StringValue(strdup(""));
+    std::vector<std::unique_ptr<Value>> args;
+    if (!ReadValueArgs(state, 2, argv, &args)) {
+        return nullptr;
     }
-    std::unique_ptr<Value, decltype(&FreeValue)> ranges_holder(ranges, FreeValue);
-    std::unique_ptr<Value, decltype(&FreeValue)> blockdev_filename_holder(blockdev_filename,
-            FreeValue);
+
+    const Value* blockdev_filename = args[0].get();
+    const Value* ranges = args[1].get();
 
     if (blockdev_filename->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "blockdev_filename argument to %s must be string",
                    name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
     if (ranges->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "ranges argument to %s must be string", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
-    int fd = open(blockdev_filename->data, O_RDWR);
-    unique_fd fd_holder(fd);
-    if (fd < 0) {
-        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s", blockdev_filename->data,
-                   strerror(errno));
-        return StringValue(strdup(""));
+    android::base::unique_fd fd(ota_open(blockdev_filename->data.c_str(), O_RDWR));
+    if (fd == -1) {
+        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s",
+                   blockdev_filename->data.c_str(), strerror(errno));
+        return StringValue("");
     }
 
     RangeSet rs;
@@ -1756,16 +1716,16 @@ Value* RangeSha1Fn(const char* name, State* state, int /* argc */, Expr* argv[])
     std::vector<uint8_t> buffer(BLOCKSIZE);
     for (size_t i = 0; i < rs.count; ++i) {
         if (!check_lseek(fd, (off64_t)rs.pos[i*2] * BLOCKSIZE, SEEK_SET)) {
-            ErrorAbort(state, kLseekFailure, "failed to seek %s: %s", blockdev_filename->data,
-                       strerror(errno));
-            return StringValue(strdup(""));
+            ErrorAbort(state, kLseekFailure, "failed to seek %s: %s",
+                       blockdev_filename->data.c_str(), strerror(errno));
+            return StringValue("");
         }
 
         for (size_t j = rs.pos[i*2]; j < rs.pos[i*2+1]; ++j) {
             if (read_all(fd, buffer, BLOCKSIZE) == -1) {
-                ErrorAbort(state, kFreadFailure, "failed to read %s: %s", blockdev_filename->data,
-                        strerror(errno));
-                return StringValue(strdup(""));
+                ErrorAbort(state, kFreadFailure, "failed to read %s: %s",
+                           blockdev_filename->data.c_str(), strerror(errno));
+                return StringValue("");
             }
 
             SHA1_Update(&ctx, buffer.data(), BLOCKSIZE);
@@ -1774,7 +1734,7 @@ Value* RangeSha1Fn(const char* name, State* state, int /* argc */, Expr* argv[])
     uint8_t digest[SHA_DIGEST_LENGTH];
     SHA1_Final(digest, &ctx);
 
-    return StringValue(strdup(print_sha1(digest).c_str()));
+    return StringValue(print_sha1(digest));
 }
 
 // This function checks if a device has been remounted R/W prior to an incremental
@@ -1783,33 +1743,32 @@ Value* RangeSha1Fn(const char* name, State* state, int /* argc */, Expr* argv[])
 // if executes successfully and an empty string otherwise.
 
 Value* CheckFirstBlockFn(const char* name, State* state, int argc, Expr* argv[]) {
-    Value* arg_filename;
-
-    if (ReadValueArgs(state, argv, 1, &arg_filename) < 0) {
+    std::vector<std::unique_ptr<Value>> args;
+    if (!ReadValueArgs(state, 1, argv, &args)) {
         return nullptr;
     }
-    std::unique_ptr<Value, decltype(&FreeValue)> filename(arg_filename, FreeValue);
 
-    if (filename->type != VAL_STRING) {
+    const Value* arg_filename = args[0].get();
+
+    if (arg_filename->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "filename argument to %s must be string", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
-    int fd = open(arg_filename->data, O_RDONLY);
-    unique_fd fd_holder(fd);
+    android::base::unique_fd fd(ota_open(arg_filename->data.c_str(), O_RDONLY));
     if (fd == -1) {
-        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s", arg_filename->data,
+        ErrorAbort(state, kFileOpenFailure, "open \"%s\" failed: %s", arg_filename->data.c_str(),
                    strerror(errno));
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     RangeSet blk0 {1 /*count*/, 1/*size*/, std::vector<size_t> {0, 1}/*position*/};
     std::vector<uint8_t> block0_buffer(BLOCKSIZE);
 
     if (ReadBlocks(blk0, block0_buffer, fd) == -1) {
-        ErrorAbort(state, kFreadFailure, "failed to read %s: %s", arg_filename->data,
+        ErrorAbort(state, kFreadFailure, "failed to read %s: %s", arg_filename->data.c_str(),
                 strerror(errno));
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     // https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout
@@ -1827,52 +1786,50 @@ Value* CheckFirstBlockFn(const char* name, State* state, int argc, Expr* argv[])
         uiPrintf(state, "Last remount happened on %s", ctime(&mount_time));
     }
 
-    return StringValue(strdup("t"));
+    return StringValue("t");
 }
 
 
 Value* BlockImageRecoverFn(const char* name, State* state, int argc, Expr* argv[]) {
-    Value* arg_filename;
-    Value* arg_ranges;
-
-    if (ReadValueArgs(state, argv, 2, &arg_filename, &arg_ranges) < 0) {
-        return NULL;
+    std::vector<std::unique_ptr<Value>> args;
+    if (!ReadValueArgs(state, 2, argv, &args)) {
+        return nullptr;
     }
 
-    std::unique_ptr<Value, decltype(&FreeValue)> filename(arg_filename, FreeValue);
-    std::unique_ptr<Value, decltype(&FreeValue)> ranges(arg_ranges, FreeValue);
+    const Value* filename = args[0].get();
+    const Value* ranges = args[1].get();
 
     if (filename->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "filename argument to %s must be string", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
     if (ranges->type != VAL_STRING) {
         ErrorAbort(state, kArgsParsingFailure, "ranges argument to %s must be string", name);
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     // Output notice to log when recover is attempted
-    fprintf(stderr, "%s image corrupted, attempting to recover...\n", filename->data);
+    LOG(INFO) << filename->data << " image corrupted, attempting to recover...";
 
     // When opened with O_RDWR, libfec rewrites corrupted blocks when they are read
-    fec::io fh(filename->data, O_RDWR);
+    fec::io fh(filename->data.c_str(), O_RDWR);
 
     if (!fh) {
-        ErrorAbort(state, kLibfecFailure, "fec_open \"%s\" failed: %s", filename->data,
+        ErrorAbort(state, kLibfecFailure, "fec_open \"%s\" failed: %s", filename->data.c_str(),
                    strerror(errno));
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     if (!fh.has_ecc() || !fh.has_verity()) {
         ErrorAbort(state, kLibfecFailure, "unable to use metadata to correct errors");
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     fec_status status;
 
     if (!fh.get_status(status)) {
         ErrorAbort(state, kLibfecFailure, "failed to read FEC status");
-        return StringValue(strdup(""));
+        return StringValue("");
     }
 
     RangeSet rs;
@@ -1889,8 +1846,8 @@ Value* BlockImageRecoverFn(const char* name, State* state, int argc, Expr* argv[
 
             if (fh.pread(buffer, BLOCKSIZE, (off64_t)j * BLOCKSIZE) != BLOCKSIZE) {
                 ErrorAbort(state, kLibfecFailure, "failed to recover %s (block %zu): %s",
-                           filename->data, j, strerror(errno));
-                return StringValue(strdup(""));
+                           filename->data.c_str(), j, strerror(errno));
+                return StringValue("");
             }
 
             // If we want to be able to recover from a situation where rewriting a corrected
@@ -1905,8 +1862,8 @@ Value* BlockImageRecoverFn(const char* name, State* state, int argc, Expr* argv[
             //     read and check if the errors field value has increased.
         }
     }
-    fprintf(stderr, "...%s image recovered successfully.\n", filename->data);
-    return StringValue(strdup("t"));
+    LOG(INFO) << "..." << filename->data << " image recovered successfully.";
+    return StringValue("t");
 }
 
 void RegisterBlockImageFunctions() {