dump: Propagate errors into qmp_dump_guest_memory()

The code calls dump_error() on error, and even passes it a suitable
message.  However, the message is thrown away, and its callers pass
up only success/failure.  All qmp_dump_guest_memory() can do is set
a generic error.

Propagate the errors properly, so qmp_dump_guest_memory() can return
a more useful error.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 82 insertions, 83 deletions

diff --git a/dump.c b/dump.c
index 71d3e94..07d2300 100644
--- a/dump.c
+++ b/dump.c
@@ -81,9 +81,10 @@ static int dump_cleanup(DumpState *s)
     return 0;
 }
 
-static void dump_error(DumpState *s, const char *reason)
+static void dump_error(DumpState *s, const char *reason, Error **errp)
 {
     dump_cleanup(s);
+    error_setg(errp, "%s", reason);
 }
 
 static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
@@ -99,7 +100,7 @@ static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
     return 0;
 }
 
-static int write_elf64_header(DumpState *s)
+static int write_elf64_header(DumpState *s, Error **errp)
 {
     Elf64_Ehdr elf_header;
     int ret;
@@ -126,14 +127,14 @@ static int write_elf64_header(DumpState *s)
 
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write elf header.\n");
+        dump_error(s, "dump: failed to write elf header", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf32_header(DumpState *s)
+static int write_elf32_header(DumpState *s, Error **errp)
 {
     Elf32_Ehdr elf_header;
     int ret;
@@ -160,7 +161,7 @@ static int write_elf32_header(DumpState *s)
 
     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write elf header.\n");
+        dump_error(s, "dump: failed to write elf header", errp);
         return -1;
     }
 
@@ -169,7 +170,7 @@ static int write_elf32_header(DumpState *s)
 
 static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
-                            hwaddr filesz)
+                            hwaddr filesz, Error **errp)
 {
     Elf64_Phdr phdr;
     int ret;
@@ -186,7 +187,7 @@ static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
@@ -195,7 +196,7 @@ static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 
 static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
-                            hwaddr filesz)
+                            hwaddr filesz, Error **errp)
 {
     Elf32_Phdr phdr;
     int ret;
@@ -212,14 +213,14 @@ static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf64_note(DumpState *s)
+static int write_elf64_note(DumpState *s, Error **errp)
 {
     Elf64_Phdr phdr;
     hwaddr begin = s->memory_offset - s->note_size;
@@ -235,7 +236,7 @@ static int write_elf64_note(DumpState *s)
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
@@ -247,7 +248,8 @@ static inline int cpu_index(CPUState *cpu)
     return cpu->cpu_index + 1;
 }
 
-static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
+static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
+                             Error **errp)
 {
     CPUState *cpu;
     int ret;
@@ -257,7 +259,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(f, cpu, id, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write elf notes.\n");
+            dump_error(s, "dump: failed to write elf notes", errp);
             return -1;
         }
     }
@@ -265,7 +267,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(f, cpu, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write CPU status.\n");
+            dump_error(s, "dump: failed to write CPU status", errp);
             return -1;
         }
     }
@@ -273,7 +275,7 @@ static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
     return 0;
 }
 
-static int write_elf32_note(DumpState *s)
+static int write_elf32_note(DumpState *s, Error **errp)
 {
     hwaddr begin = s->memory_offset - s->note_size;
     Elf32_Phdr phdr;
@@ -289,14 +291,15 @@ static int write_elf32_note(DumpState *s)
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write program header table.\n");
+        dump_error(s, "dump: failed to write program header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
+static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
+                             Error **errp)
 {
     CPUState *cpu;
     int ret;
@@ -306,7 +309,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(f, cpu, id, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write elf notes.\n");
+            dump_error(s, "dump: failed to write elf notes", errp);
             return -1;
         }
     }
@@ -314,7 +317,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(f, cpu, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to write CPU status.\n");
+            dump_error(s, "dump: failed to write CPU status", errp);
             return -1;
         }
     }
@@ -322,7 +325,7 @@ static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
     return 0;
 }
 
-static int write_elf_section(DumpState *s, int type)
+static int write_elf_section(DumpState *s, int type, Error **errp)
 {
     Elf32_Shdr shdr32;
     Elf64_Shdr shdr64;
@@ -344,20 +347,20 @@ static int write_elf_section(DumpState *s, int type)
 
     ret = fd_write_vmcore(&shdr, shdr_size, s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write section header table.\n");
+        dump_error(s, "dump: failed to write section header table", errp);
         return -1;
     }
 
     return 0;
 }
 
-static int write_data(DumpState *s, void *buf, int length)
+static int write_data(DumpState *s, void *buf, int length, Error **errp)
 {
     int ret;
 
     ret = fd_write_vmcore(buf, length, s);
     if (ret < 0) {
-        dump_error(s, "dump: failed to save memory.\n");
+        dump_error(s, "dump: failed to save memory", errp);
         return -1;
     }
 
@@ -366,14 +369,14 @@ static int write_data(DumpState *s, void *buf, int length)
 
 /* write the memroy to vmcore. 1 page per I/O. */
 static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
-                        int64_t size)
+                        int64_t size, Error **errp)
 {
     int64_t i;
     int ret;
 
     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
-                         TARGET_PAGE_SIZE);
+                         TARGET_PAGE_SIZE, errp);
         if (ret < 0) {
             return ret;
         }
@@ -381,7 +384,7 @@ static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
 
     if ((size % TARGET_PAGE_SIZE) != 0) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
-                         size % TARGET_PAGE_SIZE);
+                         size % TARGET_PAGE_SIZE, errp);
         if (ret < 0) {
             return ret;
         }
@@ -452,7 +455,7 @@ static void get_offset_range(hwaddr phys_addr,
     }
 }
 
-static int write_elf_loads(DumpState *s)
+static int write_elf_loads(DumpState *s, Error **errp)
 {
     hwaddr offset, filesz;
     MemoryMapping *memory_mapping;
@@ -472,10 +475,10 @@ static int write_elf_loads(DumpState *s)
                          s, &offset, &filesz);
         if (s->dump_info.d_class == ELFCLASS64) {
             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset,
-                                   filesz);
+                                   filesz, errp);
         } else {
             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset,
-                                   filesz);
+                                   filesz, errp);
         }
 
         if (ret < 0) {
@@ -491,7 +494,7 @@ static int write_elf_loads(DumpState *s)
 }
 
 /* write elf header, PT_NOTE and elf note to vmcore. */
-static int dump_begin(DumpState *s)
+static int dump_begin(DumpState *s, Error **errp)
 {
     int ret;
 
@@ -521,9 +524,9 @@ static int dump_begin(DumpState *s)
 
     /* write elf header to vmcore */
     if (s->dump_info.d_class == ELFCLASS64) {
-        ret = write_elf64_header(s);
+        ret = write_elf64_header(s, errp);
     } else {
-        ret = write_elf32_header(s);
+        ret = write_elf32_header(s, errp);
     }
     if (ret < 0) {
         return -1;
@@ -531,47 +534,47 @@ static int dump_begin(DumpState *s)
 
     if (s->dump_info.d_class == ELFCLASS64) {
         /* write PT_NOTE to vmcore */
-        if (write_elf64_note(s) < 0) {
+        if (write_elf64_note(s, errp) < 0) {
             return -1;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s) < 0) {
+        if (write_elf_loads(s, errp) < 0) {
             return -1;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 1) < 0) {
+            if (write_elf_section(s, 1, errp) < 0) {
                 return -1;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf64_notes(fd_write_vmcore, s) < 0) {
+        if (write_elf64_notes(fd_write_vmcore, s, errp) < 0) {
             return -1;
         }
 
     } else {
         /* write PT_NOTE to vmcore */
-        if (write_elf32_note(s) < 0) {
+        if (write_elf32_note(s, errp) < 0) {
             return -1;
         }
 
         /* write all PT_LOAD to vmcore */
-        if (write_elf_loads(s) < 0) {
+        if (write_elf_loads(s, errp) < 0) {
             return -1;
         }
 
         /* write section to vmcore */
         if (s->have_section) {
-            if (write_elf_section(s, 0) < 0) {
+            if (write_elf_section(s, 0, errp) < 0) {
                 return -1;
             }
         }
 
         /* write notes to vmcore */
-        if (write_elf32_notes(fd_write_vmcore, s) < 0) {
+        if (write_elf32_notes(fd_write_vmcore, s, errp) < 0) {
             return -1;
         }
     }
@@ -614,7 +617,7 @@ static int get_next_block(DumpState *s, GuestPhysBlock *block)
 }
 
 /* write all memory to vmcore */
-static int dump_iterate(DumpState *s)
+static int dump_iterate(DumpState *s, Error **errp)
 {
     GuestPhysBlock *block;
     int64_t size;
@@ -630,7 +633,7 @@ static int dump_iterate(DumpState *s)
                 size -= block->target_end - (s->begin + s->length);
             }
         }
-        ret = write_memory(s, block, s->start, size);
+        ret = write_memory(s, block, s->start, size, errp);
         if (ret == -1) {
             return ret;
         }
@@ -643,16 +646,16 @@ static int dump_iterate(DumpState *s)
     }
 }
 
-static int create_vmcore(DumpState *s)
+static int create_vmcore(DumpState *s, Error **errp)
 {
     int ret;
 
-    ret = dump_begin(s);
+    ret = dump_begin(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = dump_iterate(s);
+    ret = dump_iterate(s, errp);
     if (ret < 0) {
         return -1;
     }
@@ -738,7 +741,7 @@ static int buf_write_note(const void *buf, size_t size, void *opaque)
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header32(DumpState *s)
+static int create_header32(DumpState *s, Error **errp)
 {
     int ret = 0;
     DiskDumpHeader32 *dh = NULL;
@@ -784,7 +787,7 @@ static int create_header32(DumpState *s)
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
-        dump_error(s, "dump: failed to write disk dump header.\n");
+        dump_error(s, "dump: failed to write disk dump header", errp);
         ret = -1;
         goto out;
     }
@@ -804,7 +807,7 @@ static int create_header32(DumpState *s)
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
-        dump_error(s, "dump: failed to write kdump sub header.\n");
+        dump_error(s, "dump: failed to write kdump sub header", errp);
         ret = -1;
         goto out;
     }
@@ -814,14 +817,14 @@ static int create_header32(DumpState *s)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf32_notes(buf_write_note, s) < 0) {
+    if (write_elf32_notes(buf_write_note, s, errp) < 0) {
         ret = -1;
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
-        dump_error(s, "dump: failed to write notes");
+        dump_error(s, "dump: failed to write notes", errp);
         ret = -1;
         goto out;
     }
@@ -843,7 +846,7 @@ out:
 }
 
 /* write common header, sub header and elf note to vmcore */
-static int create_header64(DumpState *s)
+static int create_header64(DumpState *s, Error **errp)
 {
     int ret = 0;
     DiskDumpHeader64 *dh = NULL;
@@ -889,7 +892,7 @@ static int create_header64(DumpState *s)
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
-        dump_error(s, "dump: failed to write disk dump header.\n");
+        dump_error(s, "dump: failed to write disk dump header", errp);
         ret = -1;
         goto out;
     }
@@ -909,7 +912,7 @@ static int create_header64(DumpState *s)
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
-        dump_error(s, "dump: failed to write kdump sub header.\n");
+        dump_error(s, "dump: failed to write kdump sub header", errp);
         ret = -1;
         goto out;
     }
@@ -919,14 +922,14 @@ static int create_header64(DumpState *s)
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
-    if (write_elf64_notes(buf_write_note, s) < 0) {
+    if (write_elf64_notes(buf_write_note, s, errp) < 0) {
         ret = -1;
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
-        dump_error(s, "dump: failed to write notes");
+        dump_error(s, "dump: failed to write notes", errp);
         ret = -1;
         goto out;
     }
@@ -947,12 +950,12 @@ out:
     return ret;
 }
 
-static int write_dump_header(DumpState *s)
+static int write_dump_header(DumpState *s, Error **errp)
 {
     if (s->dump_info.d_class == ELFCLASS32) {
-        return create_header32(s);
+        return create_header32(s, errp);
     } else {
-        return create_header64(s);
+        return create_header64(s, errp);
     }
 }
 
@@ -1066,7 +1069,7 @@ static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
     return true;
 }
 
-static int write_dump_bitmap(DumpState *s)
+static int write_dump_bitmap(DumpState *s, Error **errp)
 {
     int ret = 0;
     uint64_t last_pfn, pfn;
@@ -1087,7 +1090,7 @@ static int write_dump_bitmap(DumpState *s)
     while (get_next_page(&block_iter, &pfn, NULL, s)) {
         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to set dump_bitmap.\n");
+            dump_error(s, "dump: failed to set dump_bitmap", errp);
             ret = -1;
             goto out;
         }
@@ -1105,7 +1108,7 @@ static int write_dump_bitmap(DumpState *s)
         ret = set_dump_bitmap(last_pfn, last_pfn + PFN_BUFBITMAP, false,
                               dump_bitmap_buf, s);
         if (ret < 0) {
-            dump_error(s, "dump: failed to sync dump_bitmap.\n");
+            dump_error(s, "dump: failed to sync dump_bitmap", errp);
             ret = -1;
             goto out;
         }
@@ -1197,7 +1200,7 @@ static inline bool is_zero_page(const uint8_t *buf, size_t page_size)
     return buffer_is_zero(buf, page_size);
 }
 
-static int write_dump_pages(DumpState *s)
+static int write_dump_pages(DumpState *s, Error **errp)
 {
     int ret = 0;
     DataCache page_desc, page_data;
@@ -1241,7 +1244,7 @@ static int write_dump_pages(DumpState *s)
     ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
     g_free(buf);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write page data(zero page).\n");
+        dump_error(s, "dump: failed to write page data (zero page)", errp);
         goto out;
     }
 
@@ -1257,7 +1260,7 @@ static int write_dump_pages(DumpState *s)
             ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
                               false);
             if (ret < 0) {
-                dump_error(s, "dump: failed to write page desc.\n");
+                dump_error(s, "dump: failed to write page desc", errp);
                 goto out;
             }
         } else {
@@ -1282,7 +1285,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #ifdef CONFIG_LZO
@@ -1295,7 +1298,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #endif
@@ -1309,7 +1312,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
 #endif
@@ -1324,7 +1327,7 @@ static int write_dump_pages(DumpState *s)
 
                 ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
                 if (ret < 0) {
-                    dump_error(s, "dump: failed to write page data.\n");
+                    dump_error(s, "dump: failed to write page data", errp);
                     goto out;
                 }
             }
@@ -1336,7 +1339,7 @@ static int write_dump_pages(DumpState *s)
 
             ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
             if (ret < 0) {
-                dump_error(s, "dump: failed to write page desc.\n");
+                dump_error(s, "dump: failed to write page desc", errp);
                 goto out;
             }
         }
@@ -1344,12 +1347,12 @@ static int write_dump_pages(DumpState *s)
 
     ret = write_cache(&page_desc, NULL, 0, true);
     if (ret < 0) {
-        dump_error(s, "dump: failed to sync cache for page_desc.\n");
+        dump_error(s, "dump: failed to sync cache for page_desc", errp);
         goto out;
     }
     ret = write_cache(&page_data, NULL, 0, true);
     if (ret < 0) {
-        dump_error(s, "dump: failed to sync cache for page_data.\n");
+        dump_error(s, "dump: failed to sync cache for page_data", errp);
         goto out;
     }
 
@@ -1366,7 +1369,7 @@ out:
     return ret;
 }
 
-static int create_kdump_vmcore(DumpState *s)
+static int create_kdump_vmcore(DumpState *s, Error **errp)
 {
     int ret;
 
@@ -1394,28 +1397,28 @@ static int create_kdump_vmcore(DumpState *s)
 
     ret = write_start_flat_header(s->fd);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write start flat header.\n");
+        dump_error(s, "dump: failed to write start flat header", errp);
         return -1;
     }
 
-    ret = write_dump_header(s);
+    ret = write_dump_header(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = write_dump_bitmap(s);
+    ret = write_dump_bitmap(s, errp);
     if (ret < 0) {
         return -1;
     }
 
-    ret = write_dump_pages(s);
+    ret = write_dump_pages(s, errp);
     if (ret < 0) {
         return -1;
     }
 
     ret = write_end_flat_header(s->fd);
     if (ret < 0) {
-        dump_error(s, "dump: failed to write end flat header.\n");
+        dump_error(s, "dump: failed to write end flat header", errp);
         return -1;
     }
 
@@ -1699,13 +1702,9 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     }
 
     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
-        if (create_kdump_vmcore(s) < 0) {
-            error_set(errp, QERR_IO_ERROR);
-        }
+        create_kdump_vmcore(s, errp);
     } else {
-        if (create_vmcore(s) < 0) {
-            error_set(errp, QERR_IO_ERROR);
-        }
+        create_vmcore(s, errp);
     }
 
     g_free(s);