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author | Timm Bäder <tbaeder@redhat.com> | 2021-01-08 09:09:56 +0100 |
---|---|---|
committer | Mark Wielaard <mark@klomp.org> | 2021-01-28 23:57:06 +0100 |
commit | 9c15e1e06eb088d6b632403a41a9e47b91f58b5f (patch) | |
tree | f49301a9e43762b14a6e1ae817549fc5ac1fdb9b | |
parent | 67a912f0b81047d42881be3c40c8404c2711711c (diff) | |
download | elfutils-9c15e1e06eb088d6b632403a41a9e47b91f58b5f.tar.gz |
elf-from-memory: Refactor to get rid of nested function
Try to unify the 32/64 bit code paths and get rid of the nested
handle_segment() this way.
Signed-off-by: Timm Bäder <tbaeder@redhat.com>
-rw-r--r-- | libdwfl/ChangeLog | 6 | ||||
-rw-r--r-- | libdwfl/elf-from-memory.c | 115 |
2 files changed, 56 insertions, 65 deletions
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index f17eafe7..5058f5f8 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,5 +1,11 @@ 2021-01-08 Timm Bäder <tbaeder@redhat.com> + * elf-from-memory.c (elf_from_remote_memory): Add for loop over + switch. inline handle_segment call, set vaddr, offset and filesz + directly based on class. + +2021-01-08 Timm Bäder <tbaeder@redhat.com> + * elf-from-memory.c (elf_from_remote_memory): Use if instead of switch on class. Set new vaddr, memsz, offset and filesz variables. Inline handle_segment function check and set loadbase, diff --git a/libdwfl/elf-from-memory.c b/libdwfl/elf-from-memory.c index 933ab864..a0ef0014 100644 --- a/libdwfl/elf-from-memory.c +++ b/libdwfl/elf-from-memory.c @@ -292,80 +292,65 @@ elf_from_remote_memory (GElf_Addr ehdr_vma, goto no_memory; } - switch (ehdr.e32.e_ident[EI_CLASS]) + for (uint_fast16_t i = 0; i < phnum; ++i) { - /* Reads the given segment. Returns true if reading fails, - false otherwise. */ - inline bool handle_segment (GElf_Addr vaddr, GElf_Off offset, - GElf_Xword filesz) - { - GElf_Off start = offset & -pagesize; - GElf_Off end = (offset + filesz + pagesize - 1) & -pagesize; - if (end > (GElf_Off) contents_size) - end = contents_size; - nread = (*read_memory) (arg, buffer + start, - (loadbase + vaddr) & -pagesize, - end - start, end - start); - return nread <= 0; - } + GElf_Word type = class32 ? (*p32)[i].p_type : (*p64)[i].p_type; - case ELFCLASS32: - for (uint_fast16_t i = 0; i < phnum; ++i) - if ((*p32)[i].p_type == PT_LOAD) - if (handle_segment ((*p32)[i].p_vaddr, (*p32)[i].p_offset, - (*p32)[i].p_filesz)) - goto read_error; - - /* If the segments visible in memory didn't include the section - headers, then clear them from the file header. */ - if (contents_size < shdrs_end) - { - ehdr.e32.e_shoff = 0; - ehdr.e32.e_shnum = 0; - ehdr.e32.e_shstrndx = 0; - } + if (type != PT_LOAD) + continue; + + GElf_Addr vaddr = class32 ? (*p32)[i].p_vaddr : (*p64)[i].p_vaddr; + GElf_Off offset = class32 ? (*p32)[i].p_offset : (*p64)[i].p_offset; + GElf_Xword filesz = class32 ? (*p32)[i].p_filesz : (*p64)[i].p_filesz; + + GElf_Off start = offset & -pagesize; + GElf_Off end = (offset + filesz + pagesize - 1) & -pagesize; + if (end > (GElf_Off) contents_size) + end = contents_size; + nread = (*read_memory) (arg, buffer + start, + (loadbase + vaddr) & -pagesize, + end - start, end - start); + if (nread <= 0) + goto read_error; + } + + /* If the segments visible in memory didn't include the section + headers, then clear them from the file header. */ + if (contents_size < shdrs_end) + { + if (class32) + { + ehdr.e32.e_shoff = 0; + ehdr.e32.e_shnum = 0; + ehdr.e32.e_shstrndx = 0; + } + else + { + ehdr.e64.e_shoff = 0; + ehdr.e64.e_shnum = 0; + ehdr.e64.e_shstrndx = 0; + } + } - /* This will normally have been in the first PT_LOAD segment. But it - conceivably could be missing, and we might have just changed it. */ - xlatefrom.d_type = xlateto.d_type = ELF_T_EHDR; + /* This will normally have been in the first PT_LOAD segment. But it + conceivably could be missing, and we might have just changed it. */ + xlatefrom.d_type = xlateto.d_type = ELF_T_EHDR; + xlateto.d_buf = buffer; + if (class32) + { xlatefrom.d_size = xlateto.d_size = sizeof ehdr.e32; xlatefrom.d_buf = &ehdr.e32; - xlateto.d_buf = buffer; if (elf32_xlatetof (&xlateto, &xlatefrom, - ehdr.e32.e_ident[EI_DATA]) == NULL) - goto libelf_error; - break; - - case ELFCLASS64: - for (uint_fast16_t i = 0; i < phnum; ++i) - if ((*p64)[i].p_type == PT_LOAD) - if (handle_segment ((*p64)[i].p_vaddr, (*p64)[i].p_offset, - (*p64)[i].p_filesz)) - goto read_error; - - /* If the segments visible in memory didn't include the section - headers, then clear them from the file header. */ - if (contents_size < shdrs_end) - { - ehdr.e64.e_shoff = 0; - ehdr.e64.e_shnum = 0; - ehdr.e64.e_shstrndx = 0; - } - - /* This will normally have been in the first PT_LOAD segment. But it - conceivably could be missing, and we might have just changed it. */ - xlatefrom.d_type = xlateto.d_type = ELF_T_EHDR; + ehdr.e32.e_ident[EI_DATA]) == NULL) + goto libelf_error; + } + else + { xlatefrom.d_size = xlateto.d_size = sizeof ehdr.e64; xlatefrom.d_buf = &ehdr.e64; - xlateto.d_buf = buffer; if (elf64_xlatetof (&xlateto, &xlatefrom, - ehdr.e64.e_ident[EI_DATA]) == NULL) - goto libelf_error; - break; - - default: - abort (); - break; + ehdr.e64.e_ident[EI_DATA]) == NULL) + goto libelf_error; } free (phdrsp); |