Re: [Qemu-devel] [PATCH v8 11/23] Add symbol table callback interface to load_elf

[Philippe Mathieu-Daudé]

On 03/02/2018 02:51 PM, Michael Clark wrote:
> The RISC-V HTIF (Host Target Interface) console device requires access
> to the symbol table to locate the 'tohost' and 'fromhost' symbols.
> 
> Reviewed-by: Richard Henderson 
> Signed-off-by: Michael Clark 

Reviewed-by: Philippe Mathieu-Daudé 

> ---
>  hw/core/loader.c | 18 --
>  include/hw/elf_ops.h | 34 +-
>  include/hw/loader.h  | 17 -
>  3 files changed, 53 insertions(+), 16 deletions(-)
> 
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index c08f130..1d26c6e 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -450,6 +450,20 @@ int load_elf_ram(const char *filename,
>   int clear_lsb, int data_swab, AddressSpace *as,
>   bool load_rom)
>  {
> +return load_elf_ram_sym(filename, translate_fn, translate_opaque,
> +pentry, lowaddr, highaddr, big_endian,
> +elf_machine, clear_lsb, data_swab, as,
> +load_rom, NULL);
> +}
> +
> +/* return < 0 if error, otherwise the number of bytes loaded in memory */
> +int load_elf_ram_sym(const char *filename,
> + uint64_t (*translate_fn)(void *, uint64_t),
> + void *translate_opaque, uint64_t *pentry,
> + uint64_t *lowaddr, uint64_t *highaddr, int big_endian,
> + int elf_machine, int clear_lsb, int data_swab,
> + AddressSpace *as, bool load_rom, symbol_fn_t sym_cb)
> +{
>  int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
>  uint8_t e_ident[EI_NIDENT];
>  
> @@ -488,11 +502,11 @@ int load_elf_ram(const char *filename,
>  if (e_ident[EI_CLASS] == ELFCLASS64) {
>  ret = load_elf64(filename, fd, translate_fn, translate_opaque, 
> must_swab,
>   pentry, lowaddr, highaddr, elf_machine, clear_lsb,
> - data_swab, as, load_rom);
> + data_swab, as, load_rom, sym_cb);
>  } else {
>  ret = load_elf32(filename, fd, translate_fn, translate_opaque, 
> must_swab,
>   pentry, lowaddr, highaddr, elf_machine, clear_lsb,
> - data_swab, as, load_rom);
> + data_swab, as, load_rom, sym_cb);
>  }
>  
>   fail:
> diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
> index d192e7e..b6e19e3 100644
> --- a/include/hw/elf_ops.h
> +++ b/include/hw/elf_ops.h
> @@ -105,7 +105,7 @@ static int glue(symcmp, SZ)(const void *s0, const void 
> *s1)
>  }
>  
>  static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
> -  int clear_lsb)
> +  int clear_lsb, symbol_fn_t sym_cb)
>  {
>  struct elf_shdr *symtab, *strtab, *shdr_table = NULL;
>  struct elf_sym *syms = NULL;
> @@ -133,10 +133,26 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, 
> int fd, int must_swab,
>  
>  nsyms = symtab->sh_size / sizeof(struct elf_sym);
>  
> +/* String table */
> +if (symtab->sh_link >= ehdr->e_shnum) {
> +goto fail;
> +}
> +strtab = _table[symtab->sh_link];
> +
> +str = load_at(fd, strtab->sh_offset, strtab->sh_size);
> +if (!str) {
> +goto fail;
> +}
> +
>  i = 0;
>  while (i < nsyms) {
> -if (must_swab)
> +if (must_swab) {
>  glue(bswap_sym, SZ)([i]);
> +}
> +if (sym_cb) {
> +sym_cb(str + syms[i].st_name, syms[i].st_info,
> +   syms[i].st_value, syms[i].st_size);
> +}
>  /* We are only interested in function symbols.
> Throw everything else away.  */
>  if (syms[i].st_shndx == SHN_UNDEF ||
> @@ -163,15 +179,6 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, 
> int fd, int must_swab,
>  }
>  }
>  
> -/* String table */
> -if (symtab->sh_link >= ehdr->e_shnum)
> -goto fail;
> -strtab = _table[symtab->sh_link];
> -
> -str = load_at(fd, strtab->sh_offset, strtab->sh_size);
> -if (!str)
> -goto fail;
> -
>  /* Commit */
>  s = g_malloc0(sizeof(*s));
>  s->lookup_symbol = glue(lookup_symbol, SZ);
> @@ -264,7 +271,8 @@ static int glue(load_elf, SZ)(const char *name, int fd,
>int must_swab, uint64_t *pentry,
>uint64_t *lowaddr, uint64_t *highaddr,
>int elf_machine, int clear_lsb, int data_swab,
> -  AddressSpace *as, bool load_rom)
> +  AddressSpace *as, bool load_rom,
> +  symbol_fn_t sym_cb)
>  {
>  struct elfhdr ehdr;
>  struct elf_phdr *phdr = NULL, *ph;
> @@ -329,7 +337,7 @@ static int 

[Qemu-devel] [PATCH v8 11/23] Add symbol table callback interface to load_elf

[Michael Clark]

The RISC-V HTIF (Host Target Interface) console device requires access
to the symbol table to locate the 'tohost' and 'fromhost' symbols.

Reviewed-by: Richard Henderson 
Signed-off-by: Michael Clark 
---
 hw/core/loader.c | 18 --
 include/hw/elf_ops.h | 34 +-
 include/hw/loader.h  | 17 -
 3 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index c08f130..1d26c6e 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -450,6 +450,20 @@ int load_elf_ram(const char *filename,
  int clear_lsb, int data_swab, AddressSpace *as,
  bool load_rom)
 {
+return load_elf_ram_sym(filename, translate_fn, translate_opaque,
+pentry, lowaddr, highaddr, big_endian,
+elf_machine, clear_lsb, data_swab, as,
+load_rom, NULL);
+}
+
+/* return < 0 if error, otherwise the number of bytes loaded in memory */
+int load_elf_ram_sym(const char *filename,
+ uint64_t (*translate_fn)(void *, uint64_t),
+ void *translate_opaque, uint64_t *pentry,
+ uint64_t *lowaddr, uint64_t *highaddr, int big_endian,
+ int elf_machine, int clear_lsb, int data_swab,
+ AddressSpace *as, bool load_rom, symbol_fn_t sym_cb)
+{
 int fd, data_order, target_data_order, must_swab, ret = ELF_LOAD_FAILED;
 uint8_t e_ident[EI_NIDENT];
 
@@ -488,11 +502,11 @@ int load_elf_ram(const char *filename,
 if (e_ident[EI_CLASS] == ELFCLASS64) {
 ret = load_elf64(filename, fd, translate_fn, translate_opaque, 
must_swab,
  pentry, lowaddr, highaddr, elf_machine, clear_lsb,
- data_swab, as, load_rom);
+ data_swab, as, load_rom, sym_cb);
 } else {
 ret = load_elf32(filename, fd, translate_fn, translate_opaque, 
must_swab,
  pentry, lowaddr, highaddr, elf_machine, clear_lsb,
- data_swab, as, load_rom);
+ data_swab, as, load_rom, sym_cb);
 }
 
  fail:
diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
index d192e7e..b6e19e3 100644
--- a/include/hw/elf_ops.h
+++ b/include/hw/elf_ops.h
@@ -105,7 +105,7 @@ static int glue(symcmp, SZ)(const void *s0, const void *s1)
 }
 
 static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
-  int clear_lsb)
+  int clear_lsb, symbol_fn_t sym_cb)
 {
 struct elf_shdr *symtab, *strtab, *shdr_table = NULL;
 struct elf_sym *syms = NULL;
@@ -133,10 +133,26 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, 
int fd, int must_swab,
 
 nsyms = symtab->sh_size / sizeof(struct elf_sym);
 
+/* String table */
+if (symtab->sh_link >= ehdr->e_shnum) {
+goto fail;
+}
+strtab = _table[symtab->sh_link];
+
+str = load_at(fd, strtab->sh_offset, strtab->sh_size);
+if (!str) {
+goto fail;
+}
+
 i = 0;
 while (i < nsyms) {
-if (must_swab)
+if (must_swab) {
 glue(bswap_sym, SZ)([i]);
+}
+if (sym_cb) {
+sym_cb(str + syms[i].st_name, syms[i].st_info,
+   syms[i].st_value, syms[i].st_size);
+}
 /* We are only interested in function symbols.
Throw everything else away.  */
 if (syms[i].st_shndx == SHN_UNDEF ||
@@ -163,15 +179,6 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int 
fd, int must_swab,
 }
 }
 
-/* String table */
-if (symtab->sh_link >= ehdr->e_shnum)
-goto fail;
-strtab = _table[symtab->sh_link];
-
-str = load_at(fd, strtab->sh_offset, strtab->sh_size);
-if (!str)
-goto fail;
-
 /* Commit */
 s = g_malloc0(sizeof(*s));
 s->lookup_symbol = glue(lookup_symbol, SZ);
@@ -264,7 +271,8 @@ static int glue(load_elf, SZ)(const char *name, int fd,
   int must_swab, uint64_t *pentry,
   uint64_t *lowaddr, uint64_t *highaddr,
   int elf_machine, int clear_lsb, int data_swab,
-  AddressSpace *as, bool load_rom)
+  AddressSpace *as, bool load_rom,
+  symbol_fn_t sym_cb)
 {
 struct elfhdr ehdr;
 struct elf_phdr *phdr = NULL, *ph;
@@ -329,7 +337,7 @@ static int glue(load_elf, SZ)(const char *name, int fd,
 if (pentry)
*pentry = (uint64_t)(elf_sword)ehdr.e_entry;
 
-glue(load_symbols, SZ)(, fd, must_swab, clear_lsb);
+glue(load_symbols, SZ)(, fd, must_swab, clear_lsb, sym_cb);
 
 size = ehdr.e_phnum * sizeof(phdr[0]);
 if (lseek(fd, ehdr.e_phoff, SEEK_SET) != ehdr.e_phoff) {
diff --git