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author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-11-24 11:08:33 +0000 |
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committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-12-15 10:13:12 +0000 |
commit | cb5648b00f1f6f883d0d1691abc0d2fad2fcafd7 (patch) | |
tree | a1f85665bfbbb67a6a686090a0a5d1ce71f4a2a3 | |
parent | e182654151a0f6ebbe628c8f2f6b041c69adbac1 (diff) | |
download | glibc-cb5648b00f1f6f883d0d1691abc0d2fad2fcafd7.zip glibc-cb5648b00f1f6f883d0d1691abc0d2fad2fcafd7.tar.gz glibc-cb5648b00f1f6f883d0d1691abc0d2fad2fcafd7.tar.bz2 |
elf: inline lose for error handling
_dl_map_object_from_fd has complex error handling with cleanups.
It was managed by a separate function to avoid code bloat at
every failure case, but since the code was changed to use gotos
there is no longer such code bloat from inlining.
Maintaining a separate error handling function is harder as it
needs to access local state which has to be passed down. And the
same lose function was used in open_verify which is error prone.
The goto labels are changed since there is no longer a call.
The new code generates slightly smaller binary.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
-rw-r--r-- | elf/dl-load.c | 87 |
1 files changed, 39 insertions, 48 deletions
diff --git a/elf/dl-load.c b/elf/dl-load.c index 755e92e..b1865a1 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -838,30 +838,6 @@ _dl_init_paths (const char *llp, const char *source, } -static void -__attribute__ ((noreturn, noinline)) -lose (int code, int fd, const char *name, char *realname, struct link_map *l, - const char *msg, struct r_debug *r, Lmid_t nsid) -{ - /* The file might already be closed. */ - if (fd != -1) - (void) __close_nocancel (fd); - if (l != NULL && l->l_origin != (char *) -1l) - free ((char *) l->l_origin); - free (l); - free (realname); - - if (r != NULL) - { - r->r_state = RT_CONSISTENT; - _dl_debug_state (); - LIBC_PROBE (map_failed, 2, nsid, r); - } - - _dl_signal_error (code, name, NULL, msg); -} - - /* Process PT_GNU_PROPERTY program header PH in module L after PT_LOAD segments are mapped. Only one NT_GNU_PROPERTY_TYPE_0 note is handled which contains processor specific properties. @@ -973,11 +949,25 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, if (__glibc_unlikely (!_dl_get_file_id (fd, &id))) { errstring = N_("cannot stat shared object"); - call_lose_errno: + lose_errno: errval = errno; - call_lose: - lose (errval, fd, name, realname, l, errstring, - make_consistent ? r : NULL, nsid); + lose: + /* The file might already be closed. */ + if (fd != -1) + __close_nocancel (fd); + if (l != NULL && l->l_origin != (char *) -1l) + free ((char *) l->l_origin); + free (l); + free (realname); + + if (make_consistent && r != NULL) + { + r->r_state = RT_CONSISTENT; + _dl_debug_state (); + LIBC_PROBE (map_failed, 2, nsid, r); + } + + _dl_signal_error (errval, name, NULL, errstring); } /* Look again to see if the real name matched another already loaded. */ @@ -1084,7 +1074,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, fail_new: #endif errstring = N_("cannot create shared object descriptor"); - goto call_lose_errno; + goto lose_errno; } /* Extract the remaining details we need from the ELF header @@ -1103,7 +1093,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, header->e_phoff) != maplength) { errstring = N_("cannot read file data"); - goto call_lose_errno; + goto lose_errno; } } @@ -1149,14 +1139,14 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, if (__glibc_unlikely ((ph->p_align & (GLRO(dl_pagesize) - 1)) != 0)) { errstring = N_("ELF load command alignment not page-aligned"); - goto call_lose; + goto lose; } if (__glibc_unlikely (((ph->p_vaddr - ph->p_offset) & (ph->p_align - 1)) != 0)) { errstring = N_("ELF load command address/offset not properly aligned"); - goto call_lose; + goto lose; } struct loadcmd *c = &loadcmds[nloadcmds++]; @@ -1235,7 +1225,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, another error below. But we don't want to go through the calculations below using NLOADCMDS - 1. */ errstring = N_("object file has no loadable segments"); - goto call_lose; + goto lose; } /* dlopen of an executable is not valid because it is not possible @@ -1248,7 +1238,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, /* This object is loaded at a fixed address. This must never happen for objects loaded with dlopen. */ errstring = N_("cannot dynamically load executable"); - goto call_lose; + goto lose; } /* Length of the sections to be loaded. */ @@ -1261,7 +1251,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds, maplength, has_holes, loader); if (__glibc_unlikely (errstring != NULL)) - goto call_lose; + goto lose; } if (l->l_ld == 0) @@ -1269,7 +1259,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, if (__glibc_unlikely (type == ET_DYN)) { errstring = N_("object file has no dynamic section"); - goto call_lose; + goto lose; } } else @@ -1298,7 +1288,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, = N_("cannot dynamically load position-independent executable"); else errstring = N_("shared object cannot be dlopen()ed"); - goto call_lose; + goto lose; } if (l->l_phdr == NULL) @@ -1311,7 +1301,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, if (newp == NULL) { errstring = N_("cannot allocate memory for program header"); - goto call_lose_errno; + goto lose_errno; } l->l_phdr = memcpy (newp, phdr, @@ -1344,7 +1334,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, if (__mprotect ((void *) p, s, PROT_READ|PROT_WRITE) < 0) { errstring = N_("cannot change memory protections"); - goto call_lose_errno; + goto lose_errno; } __stack_prot |= PROT_READ|PROT_WRITE|PROT_EXEC; __mprotect ((void *) p, s, PROT_READ); @@ -1365,7 +1355,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, { errstring = N_("\ cannot enable executable stack as shared object requires"); - goto call_lose; + goto lose; } } @@ -1392,7 +1382,7 @@ cannot enable executable stack as shared object requires"); if (__glibc_unlikely (__close_nocancel (fd) != 0)) { errstring = N_("cannot close file descriptor"); - goto call_lose_errno; + goto lose_errno; } /* Signal that we closed the file. */ fd = -1; @@ -1671,14 +1661,15 @@ open_verify (const char *name, int fd, errval = errno; errstring = (errval == 0 ? N_("file too short") : N_("cannot read file data")); - call_lose: + lose: if (free_name) { char *realname = (char *) name; name = strdupa (realname); free (realname); } - lose (errval, fd, name, NULL, NULL, errstring, NULL, 0); + __close_nocancel (fd); + _dl_signal_error (errval, name, NULL, errstring); } /* See whether the ELF header is what we expect. */ @@ -1738,13 +1729,13 @@ open_verify (const char *name, int fd, /* Otherwise we don't know what went wrong. */ errstring = N_("internal error"); - goto call_lose; + goto lose; } if (__glibc_unlikely (ehdr->e_version != EV_CURRENT)) { errstring = N_("ELF file version does not match current one"); - goto call_lose; + goto lose; } if (! __glibc_likely (elf_machine_matches_host (ehdr))) goto close_and_out; @@ -1752,12 +1743,12 @@ open_verify (const char *name, int fd, && ehdr->e_type != ET_EXEC)) { errstring = N_("only ET_DYN and ET_EXEC can be loaded"); - goto call_lose; + goto lose; } else if (__glibc_unlikely (ehdr->e_phentsize != sizeof (ElfW(Phdr)))) { errstring = N_("ELF file's phentsize not the expected size"); - goto call_lose; + goto lose; } maplength = ehdr->e_phnum * sizeof (ElfW(Phdr)); @@ -1772,7 +1763,7 @@ open_verify (const char *name, int fd, read_error: errval = errno; errstring = N_("cannot read file data"); - goto call_lose; + goto lose; } } |