elf: Add optional function ptr to load_elf() to parse ELF notes

This patch adds an optional function pointer, 'elf_note_fn', to
load_elf() which causes load_elf() to additionally parse any
ELF program headers of type PT_NOTE and check to see if the ELF
Note is of the type specified by the 'translate_opaque' arg.
If a matching ELF Note is found then the specfied function pointer
is called to process the ELF note.

Passing a NULL function pointer results in ELF Notes being skipped.

The first consumer of this functionality is the PVHboot support
which needs to read the XEN_ELFNOTE_PHYS32_ENTRY ELF Note while
loading the uncompressed kernel binary in order to discover the
boot entry address for the x86/HVM direct boot ABI.

Signed-off-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Liam Merwick 2019-01-15 12:18:03 +00:00 committed by Paolo Bonzini
parent d455ebc4f8
commit 4366e1db16
41 changed files with 113 additions and 70 deletions

View file

@ -396,37 +396,42 @@ fail:
}
/* return < 0 if error, otherwise the number of bytes loaded in memory */
int load_elf(const char *filename, uint64_t (*translate_fn)(void *, uint64_t),
int load_elf(const char *filename,
uint64_t (*elf_note_fn)(void *, void *, bool),
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)
{
return load_elf_as(filename, translate_fn, translate_opaque, pentry,
lowaddr, highaddr, big_endian, elf_machine, clear_lsb,
data_swab, NULL);
return load_elf_as(filename, elf_note_fn, translate_fn, translate_opaque,
pentry, lowaddr, highaddr, big_endian, elf_machine,
clear_lsb, data_swab, NULL);
}
/* return < 0 if error, otherwise the number of bytes loaded in memory */
int load_elf_as(const char *filename,
uint64_t (*elf_note_fn)(void *, void *, bool),
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)
{
return load_elf_ram(filename, translate_fn, translate_opaque,
return load_elf_ram(filename, elf_note_fn, translate_fn, translate_opaque,
pentry, lowaddr, highaddr, big_endian, elf_machine,
clear_lsb, data_swab, as, true);
}
/* return < 0 if error, otherwise the number of bytes loaded in memory */
int load_elf_ram(const char *filename,
uint64_t (*elf_note_fn)(void *, void *, bool),
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)
{
return load_elf_ram_sym(filename, translate_fn, translate_opaque,
return load_elf_ram_sym(filename, elf_note_fn,
translate_fn, translate_opaque,
pentry, lowaddr, highaddr, big_endian,
elf_machine, clear_lsb, data_swab, as,
load_rom, NULL);
@ -434,6 +439,7 @@ int load_elf_ram(const char *filename,
/* return < 0 if error, otherwise the number of bytes loaded in memory */
int load_elf_ram_sym(const char *filename,
uint64_t (*elf_note_fn)(void *, void *, bool),
uint64_t (*translate_fn)(void *, uint64_t),
void *translate_opaque, uint64_t *pentry,
uint64_t *lowaddr, uint64_t *highaddr, int big_endian,
@ -476,11 +482,13 @@ int load_elf_ram_sym(const char *filename,
lseek(fd, 0, SEEK_SET);
if (e_ident[EI_CLASS] == ELFCLASS64) {
ret = load_elf64(filename, fd, translate_fn, translate_opaque, must_swab,
ret = load_elf64(filename, fd, elf_note_fn,
translate_fn, translate_opaque, must_swab,
pentry, lowaddr, highaddr, elf_machine, clear_lsb,
data_swab, as, load_rom, sym_cb);
} else {
ret = load_elf32(filename, fd, translate_fn, translate_opaque, must_swab,
ret = load_elf32(filename, fd, elf_note_fn,
translate_fn, translate_opaque, must_swab,
pentry, lowaddr, highaddr, elf_machine, clear_lsb,
data_swab, as, load_rom, sym_cb);
}