[v2,6/9] dump: Introduce dump_is_64bit() helper function

Commit Message

Janosch Frank March 10, 2022, 11:08 a.m. UTC

Checking d_class in dump_info leads to lengthy conditionals so let's
shorten things a bit by introducing a helper function.

Signed-off-by: Janosch Frank <[e-mail]>
---
 dump/dump.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

Comments

Richard Henderson March 11, 2022, 7:47 p.m. UTC | #1

On 3/10/22 03:08, Janosch Frank wrote:
> Checking d_class in dump_info leads to lengthy conditionals so let's
> shorten things a bit by introducing a helper function.
> 
> Signed-off-by: Janosch Frank <[e-mail]>
> ---
>   dump/dump.c | 19 ++++++++++++-------
>   1 file changed, 12 insertions(+), 7 deletions(-)

Reviewed-by: Richard Henderson <[e-mail]>

> @@ -1007,7 +1012,7 @@ out:
>   
>   static void write_dump_header(DumpState *s, Error **errp)
>   {
> -    if (s->dump_info.d_class == ELFCLASS32) {
> +    if (!dump_is_64bit(s)) {
>           create_header32(s, errp);
>       } else {
>           create_header64(s, errp);
> @@ -1697,7 +1702,7 @@ static void dump_init(DumpState *s, int fd, bool has_format,
>           uint32_t size;
>           uint16_t format;
>   
> -        note_head_size = s->dump_info.d_class == ELFCLASS32 ?
> +        note_head_size = !dump_is_64bit(s) ?
>               sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr);

It would be nice to standardize on positive tests, which in this case would reverse these 
two conditionals.


r~

Patch

diff --git a/dump/dump.c b/dump/dump.c
index 12b3a1a83e..8fcd23571f 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -55,6 +55,11 @@  static Error *dump_migration_blocker;
       DIV_ROUND_UP((name_size), 4) +                    \
       DIV_ROUND_UP((desc_size), 4)) * 4)
 
+static inline bool dump_is_64bit(DumpState *s)
+{
+    return s->dump_info.d_class == ELFCLASS64;
+}
+
 uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
 {
     if (s->dump_info.d_endian == ELFDATA2LSB) {
@@ -479,7 +484,7 @@  static void write_elf_loads(DumpState *s, Error **errp)
         get_offset_range(memory_mapping->phys_addr,
                          memory_mapping->length,
                          s, &offset, &filesz);
-        if (s->dump_info.d_class == ELFCLASS64) {
+        if (dump_is_64bit(s)) {
             write_elf64_load(s, memory_mapping, phdr_index++, offset,
                              filesz, errp);
         } else {
@@ -527,7 +532,7 @@  static void dump_begin(DumpState *s, Error **errp)
      */
 
     /* write elf header to vmcore */
-    if (s->dump_info.d_class == ELFCLASS64) {
+    if (dump_is_64bit(s)) {
         write_elf64_header(s, errp);
     } else {
         write_elf32_header(s, errp);
@@ -536,7 +541,7 @@  static void dump_begin(DumpState *s, Error **errp)
         return;
     }
 
-    if (s->dump_info.d_class == ELFCLASS64) {
+    if (dump_is_64bit(s)) {
         /* write PT_NOTE to vmcore */
         write_elf64_note(s, errp);
         if (*errp) {
@@ -747,7 +752,7 @@  static void get_note_sizes(DumpState *s, const void *note,
     uint64_t name_sz;
     uint64_t desc_sz;
 
-    if (s->dump_info.d_class == ELFCLASS64) {
+    if (dump_is_64bit(s)) {
         const Elf64_Nhdr *hdr = note;
         note_head_sz = sizeof(Elf64_Nhdr);
         name_sz = tswap64(hdr->n_namesz);
@@ -1007,7 +1012,7 @@  out:
 
 static void write_dump_header(DumpState *s, Error **errp)
 {
-    if (s->dump_info.d_class == ELFCLASS32) {
+    if (!dump_is_64bit(s)) {
         create_header32(s, errp);
     } else {
         create_header64(s, errp);
@@ -1697,7 +1702,7 @@  static void dump_init(DumpState *s, int fd, bool has_format,
         uint32_t size;
         uint16_t format;
 
-        note_head_size = s->dump_info.d_class == ELFCLASS32 ?
+        note_head_size = !dump_is_64bit(s) ?
             sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr);
 
         format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
@@ -1801,7 +1806,7 @@  static void dump_init(DumpState *s, int fd, bool has_format,
         }
     }
 
-    if (s->dump_info.d_class == ELFCLASS64) {
+    if (dump_is_64bit(s)) {
         s->phdr_offset = sizeof(Elf64_Ehdr);
         s->shdr_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
         s->note_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;