| Message ID | 1545422632-24444-3-git-send-email-liam.merwick@oracle.com |
|---|---|
| State | New |
| Headers | show |
| Series | QEMU changes to do PVH boot | expand |
On Fri, Dec 21, 2018 at 08:03:50PM +0000, Liam Merwick wrote: > + while (note_type != elf_note_type) { > + nhdr_namesz = nhdr->n_namesz; > + nhdr_descsz = nhdr->n_descsz; > + > + elf_note_entry_offset = nhdr_size + > + QEMU_ALIGN_UP(nhdr_namesz, phdr_align) + > + QEMU_ALIGN_UP(nhdr_descsz, phdr_align); > + > + /* If the offset calculated in this iteration exceeds the > + * supplied size, we are done and no matching note was found. > + */ Indentation is off here. QEMU uses 4-space indentation. > + if (elf_note_entry_offset > note_size) { > + return NULL; > + } > + > + /* skip to the next ELF Note entry */ > + nhdr = (void *)nhdr + elf_note_entry_offset; > + note_type = nhdr->n_type; > + } > + > + return nhdr; > +} > + > static int glue(load_elf, SZ)(const char *name, int fd, > uint64_t (*elf_note_fn)(void *, void *, bool), > uint64_t (*translate_fn)(void *, uint64_t), > @@ -512,6 +555,13 @@ static int glue(load_elf, SZ)(const char *name, int fd, > } > } > > + /* Search the ELF notes to find one with a type matching the > + * value passed in via 'translate_opaque' > + */ > + nhdr = (struct elf_note *)data; Ah, I see data gets used here! It would be clearer to move loading of data into this patch. > + assert(translate_opaque != NULL); > + nhdr = glue(get_elf_note_type, SZ)(nhdr, file_size, ph->p_align, > + *(uint64_t *)translate_opaque); Indentation is off in this hunk. QEMU uses 4-space indentation.
On 02/01/2019 13:12, Stefan Hajnoczi wrote: > On Fri, Dec 21, 2018 at 08:03:50PM +0000, Liam Merwick wrote: >> + while (note_type != elf_note_type) { >> + nhdr_namesz = nhdr->n_namesz; >> + nhdr_descsz = nhdr->n_descsz; >> + >> + elf_note_entry_offset = nhdr_size + >> + QEMU_ALIGN_UP(nhdr_namesz, phdr_align) + >> + QEMU_ALIGN_UP(nhdr_descsz, phdr_align); >> + >> + /* If the offset calculated in this iteration exceeds the >> + * supplied size, we are done and no matching note was found. >> + */ > > Indentation is off here. QEMU uses 4-space indentation. > >> + if (elf_note_entry_offset > note_size) { >> + return NULL; >> + } >> + >> + /* skip to the next ELF Note entry */ >> + nhdr = (void *)nhdr + elf_note_entry_offset; >> + note_type = nhdr->n_type; >> + } >> + >> + return nhdr; >> +} >> + >> static int glue(load_elf, SZ)(const char *name, int fd, >> uint64_t (*elf_note_fn)(void *, void *, bool), >> uint64_t (*translate_fn)(void *, uint64_t), >> @@ -512,6 +555,13 @@ static int glue(load_elf, SZ)(const char *name, int fd, >> } >> } >> >> + /* Search the ELF notes to find one with a type matching the >> + * value passed in via 'translate_opaque' >> + */ >> + nhdr = (struct elf_note *)data; > > Ah, I see data gets used here! It would be clearer to move loading of > data into this patch. Moved. > >> + assert(translate_opaque != NULL); >> + nhdr = glue(get_elf_note_type, SZ)(nhdr, file_size, ph->p_align, >> + *(uint64_t *)translate_opaque); > > Indentation is off in this hunk. QEMU uses 4-space indentation. > A few stray tabs had snuck in - I've fixed all those. Regards, Liam
diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h index 37d20a3800c1..ffbdfbe9c2d8 100644 --- a/include/hw/elf_ops.h +++ b/include/hw/elf_ops.h @@ -265,6 +265,49 @@ fail: return ret; } +/* Given 'nhdr', a pointer to a range of ELF Notes, search through them + * for a note matching type 'elf_note_type' and return a pointer to + * the matching ELF note. + */ +static struct elf_note *glue(get_elf_note_type, SZ)(struct elf_note *nhdr, + elf_word note_size, + elf_word phdr_align, + elf_word elf_note_type) +{ + elf_word nhdr_size = sizeof(struct elf_note); + elf_word elf_note_entry_offset = 0; + elf_word note_type; + elf_word nhdr_namesz; + elf_word nhdr_descsz; + + if (nhdr == NULL) { + return NULL; + } + + note_type = nhdr->n_type; + while (note_type != elf_note_type) { + nhdr_namesz = nhdr->n_namesz; + nhdr_descsz = nhdr->n_descsz; + + elf_note_entry_offset = nhdr_size + + QEMU_ALIGN_UP(nhdr_namesz, phdr_align) + + QEMU_ALIGN_UP(nhdr_descsz, phdr_align); + + /* If the offset calculated in this iteration exceeds the + * supplied size, we are done and no matching note was found. + */ + if (elf_note_entry_offset > note_size) { + return NULL; + } + + /* skip to the next ELF Note entry */ + nhdr = (void *)nhdr + elf_note_entry_offset; + note_type = nhdr->n_type; + } + + return nhdr; +} + static int glue(load_elf, SZ)(const char *name, int fd, uint64_t (*elf_note_fn)(void *, void *, bool), uint64_t (*translate_fn)(void *, uint64_t), @@ -512,6 +555,13 @@ static int glue(load_elf, SZ)(const char *name, int fd, } } + /* Search the ELF notes to find one with a type matching the + * value passed in via 'translate_opaque' + */ + nhdr = (struct elf_note *)data; + assert(translate_opaque != NULL); + nhdr = glue(get_elf_note_type, SZ)(nhdr, file_size, ph->p_align, + *(uint64_t *)translate_opaque); if (nhdr != NULL) { bool is64 = sizeof(struct elf_note) == sizeof(struct elf64_note);
Introduce a routine which, given a pointer to a range of ELF Notes, searches through them looking for a note matching the type specified and returns a pointer to the matching ELF note. Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com> --- include/hw/elf_ops.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)