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Generalize ELF parse_notes().

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Remove the knowledge of the ABI note type and brandnote from it,
instead provide it with a callback to do note-specific matching and
data fetching.  Implement callback to match against ELF brand.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
This commit is contained in:
Konstantin Belousov 2018-11-23 23:29:14 +00:00
parent eda8fe63c9
commit 92328a3251
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=340863
1 changed files with 41 additions and 21 deletions
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62
sys/kern/imgact_elf.c
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@ -2341,8 +2341,9 @@ __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
}
static boolean_t
__elfN(parse_notes)(struct image_params *imgp, Elf_Brandnote *checknote,
int32_t *osrel, const Elf_Phdr *pnote)
__elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote,
const char *note_vendor, const Elf_Phdr *pnote,
boolean_t (*cb)(const Elf_Note *, void *, boolean_t *), void *cb_arg)
{
const Elf_Note *note, *note0, *note_end;
const char *note_name;
@ -2380,27 +2381,18 @@ __elfN(parse_notes)(struct image_params *imgp, Elf_Brandnote *checknote,
(const char *)note < sizeof(Elf_Note)) {
goto retf;
}
if (note->n_namesz != checknote->hdr.n_namesz ||
note->n_descsz != checknote->hdr.n_descsz ||
note->n_type != checknote->hdr.n_type)
if (note->n_namesz != checknote->n_namesz ||
note->n_descsz != checknote->n_descsz ||
note->n_type != checknote->n_type)
goto nextnote;
note_name = (const char *)(note + 1);
if (note_name + checknote->hdr.n_namesz >=
(const char *)note_end || strncmp(checknote->vendor,
note_name, checknote->hdr.n_namesz) != 0)
if (note_name + checknote->n_namesz >=
(const char *)note_end || strncmp(note_vendor,
note_name, checknote->n_namesz) != 0)
goto nextnote;
/*
* Fetch the osreldate for binary
* from the ELF OSABI-note if necessary.
*/
if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
checknote->trans_osrel != NULL) {
res = checknote->trans_osrel(note, osrel);
if (cb(note, cb_arg, &res))
goto ret;
}
res = TRUE;
goto ret;
nextnote:
note = (const Elf_Note *)((const char *)(note + 1) +
roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) +
@ -2413,26 +2405,54 @@ __elfN(parse_notes)(struct image_params *imgp, Elf_Brandnote *checknote,
return (res);
}
struct brandnote_cb_arg {
Elf_Brandnote *brandnote;
int32_t *osrel;
};
static boolean_t
brandnote_cb(const Elf_Note *note, void *arg0, boolean_t *res)
{
struct brandnote_cb_arg *arg;
arg = arg0;
/*
* Fetch the osreldate for binary from the ELF OSABI-note if
* necessary.
*/
*res = (arg->brandnote->flags & BN_TRANSLATE_OSREL) != 0 &&
arg->brandnote->trans_osrel != NULL ?
arg->brandnote->trans_osrel(note, arg->osrel) : TRUE;
return (TRUE);
}
/*
* Try to find the appropriate ABI-note section for checknote,
* fetch the osreldate for binary from the ELF OSABI-note. Only the
* first page of the image is searched, the same as for headers.
*/
static boolean_t
__elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
__elfN(check_note)(struct image_params *imgp, Elf_Brandnote *brandnote,
int32_t *osrel)
{
const Elf_Phdr *phdr;
const Elf_Ehdr *hdr;
struct brandnote_cb_arg b_arg;
int i;
hdr = (const Elf_Ehdr *)imgp->image_header;
phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
b_arg.brandnote = brandnote;
b_arg.osrel = osrel;
for (i = 0; i < hdr->e_phnum; i++) {
if (phdr[i].p_type == PT_NOTE &&
__elfN(parse_notes)(imgp, checknote, osrel, &phdr[i]))
if (phdr[i].p_type == PT_NOTE && __elfN(parse_notes)(imgp,
&brandnote->hdr, brandnote->vendor, &phdr[i], brandnote_cb,
&b_arg)) {
return (TRUE);
}
}
return (FALSE);