diff options
Diffstat (limited to 'sysdeps/mips/dl-machine-reject-phdr.h')
| -rw-r--r-- | sysdeps/mips/dl-machine-reject-phdr.h | 326 |
1 files changed, 0 insertions, 326 deletions
diff --git a/sysdeps/mips/dl-machine-reject-phdr.h b/sysdeps/mips/dl-machine-reject-phdr.h deleted file mode 100644 index 3dde936e3b..0000000000 --- a/sysdeps/mips/dl-machine-reject-phdr.h +++ /dev/null @@ -1,326 +0,0 @@ -/* Machine-dependent program header inspection for the ELF loader. - Copyright (C) 2014-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#ifndef _DL_MACHINE_REJECT_PHDR_H -#define _DL_MACHINE_REJECT_PHDR_H 1 - -#include <unistd.h> -#include <sys/prctl.h> - -#if defined PR_GET_FP_MODE && defined PR_SET_FP_MODE -# define HAVE_PRCTL_FP_MODE 1 -#else -# define HAVE_PRCTL_FP_MODE 0 -#endif - -/* Reject an object with a debug message. */ -#define REJECT(str, args...) \ - { \ - if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)) \ - _dl_debug_printf (str, ##args); \ - return true; \ - } - -/* Search the program headers for the ABI Flags. */ - -static inline const ElfW(Phdr) * -find_mips_abiflags (const ElfW(Phdr) *phdr, ElfW(Half) phnum) -{ - const ElfW(Phdr) *ph; - - for (ph = phdr; ph < &phdr[phnum]; ++ph) - if (ph->p_type == PT_MIPS_ABIFLAGS) - return ph; - return NULL; -} - -/* Cache the FP ABI value from the PT_MIPS_ABIFLAGS program header. */ - -static bool -cached_fpabi_reject_phdr_p (struct link_map *l) -{ - if (l->l_mach.fpabi == 0) - { - const ElfW(Phdr) *ph = find_mips_abiflags (l->l_phdr, l->l_phnum); - - if (ph) - { - Elf_MIPS_ABIFlags_v0 * mips_abiflags; - if (ph->p_filesz < sizeof (Elf_MIPS_ABIFlags_v0)) - REJECT (" %s: malformed PT_MIPS_ABIFLAGS found\n", l->l_name); - - mips_abiflags = (Elf_MIPS_ABIFlags_v0 *) (l->l_addr + ph->p_vaddr); - - if (__glibc_unlikely (mips_abiflags->flags2 != 0)) - REJECT (" %s: unknown MIPS.abiflags flags2: %u\n", l->l_name, - mips_abiflags->flags2); - - l->l_mach.fpabi = mips_abiflags->fp_abi; - l->l_mach.odd_spreg = (mips_abiflags->flags1 - & MIPS_AFL_FLAGS1_ODDSPREG) != 0; - } - else - { - l->l_mach.fpabi = -1; - l->l_mach.odd_spreg = true; - } - } - return false; -} - -/* Return a description of the specified floating-point ABI. */ - -static const char * -fpabi_string (int fpabi) -{ - switch (fpabi) - { - case Val_GNU_MIPS_ABI_FP_ANY: - return "Hard or soft float"; - case Val_GNU_MIPS_ABI_FP_DOUBLE: - return "Hard float (double precision)"; - case Val_GNU_MIPS_ABI_FP_SINGLE: - return "Hard float (single precision)"; - case Val_GNU_MIPS_ABI_FP_SOFT: - return "Soft float"; - case Val_GNU_MIPS_ABI_FP_OLD_64: - return "Unsupported FP64"; - case Val_GNU_MIPS_ABI_FP_XX: - return "Hard float (32-bit CPU, Any FPU)"; - case Val_GNU_MIPS_ABI_FP_64: - return "Hard float (32-bit CPU, 64-bit FPU)"; - case Val_GNU_MIPS_ABI_FP_64A: - return "Hard float compat (32-bit CPU, 64-bit FPU)"; - case -1: - return "Double precision, single precision or soft float"; - default: - return "Unknown FP ABI"; - } -} - -/* A structure to describe the requirements of each FP ABI extension. - Each field says whether the ABI can be executed in that mode. The FR0 field - is actually overloaded and means 'default' FR mode for the ABI. I.e. For - O32 it is FR0 and for N32/N64 it is actually FR1. Since this logic is - focussed on the intricacies of mode management for O32 we call the field - FR0. */ - -struct abi_req -{ - bool single; - bool soft; - bool fr0; - bool fr1; - bool fre; -}; - -/* FP ABI requirements for all Val_GNU_MIPS_ABI_FP_* values. */ - -static const struct abi_req reqs[Val_GNU_MIPS_ABI_FP_MAX + 1] = - {{true, true, true, true, true}, /* Any */ - {false, false, true, false, true}, /* Double-float */ - {true, false, false, false, false}, /* Single-float */ - {false, true, false, false, false}, /* Soft-float */ - {false, false, false, false, false}, /* old-FP64 */ - {false, false, true, true, true}, /* FPXX */ - {false, false, false, true, false}, /* FP64 */ - {false, false, false, true, true}}; /* FP64A */ - -/* FP ABI requirements for objects without a PT_MIPS_ABIFLAGS segment. */ - -static const struct abi_req none_req = { true, true, true, false, true }; - -/* Return true iff ELF program headers are incompatible with the running - host. This verifies that floating-point ABIs are compatible and - re-configures the hardware mode if necessary. This code handles both the - DT_NEEDED libraries and the dlopen'ed libraries. It also accounts for the - impact of dlclose. */ - -static bool __attribute_used__ -elf_machine_reject_phdr_p (const ElfW(Phdr) *phdr, uint_fast16_t phnum, - const char *buf, size_t len, struct link_map *map, - int fd) -{ - const ElfW(Phdr) *ph = find_mips_abiflags (phdr, phnum); - struct link_map *l; - Lmid_t nsid; - int in_abi = -1; - struct abi_req in_req; - Elf_MIPS_ABIFlags_v0 *mips_abiflags = NULL; - bool perfect_match = false; -#if _MIPS_SIM == _ABIO32 - unsigned int cur_mode = -1; -# if HAVE_PRCTL_FP_MODE - bool cannot_mode_switch = false; - - /* Get the current hardware mode. */ - cur_mode = __prctl (PR_GET_FP_MODE); -# endif -#endif - - /* Read the attributes section. */ - if (ph != NULL) - { - ElfW(Addr) size = ph->p_filesz; - - if (ph->p_offset + size <= len) - mips_abiflags = (Elf_MIPS_ABIFlags_v0 *) (buf + ph->p_offset); - else - { - mips_abiflags = alloca (size); - __lseek (fd, ph->p_offset, SEEK_SET); - if (__libc_read (fd, (void *) mips_abiflags, size) != size) - REJECT (" unable to read PT_MIPS_ABIFLAGS\n"); - } - - if (size < sizeof (Elf_MIPS_ABIFlags_v0)) - REJECT (" contains malformed PT_MIPS_ABIFLAGS\n"); - - if (__glibc_unlikely (mips_abiflags->flags2 != 0)) - REJECT (" unknown MIPS.abiflags flags2: %u\n", mips_abiflags->flags2); - - in_abi = mips_abiflags->fp_abi; - } - - /* ANY is compatible with anything. */ - perfect_match |= (in_abi == Val_GNU_MIPS_ABI_FP_ANY); - - /* Unknown ABIs are rejected. */ - if (in_abi != -1 && in_abi > Val_GNU_MIPS_ABI_FP_MAX) - REJECT (" uses unknown FP ABI: %u\n", in_abi); - - /* Obtain the initial requirements. */ - in_req = (in_abi == -1) ? none_req : reqs[in_abi]; - - /* Check that the new requirement does not conflict with any currently - loaded object. */ - for (nsid = 0; nsid < DL_NNS; ++nsid) - for (l = GL(dl_ns)[nsid]._ns_loaded; l != NULL; l = l->l_next) - { - struct abi_req existing_req; - - if (cached_fpabi_reject_phdr_p (l)) - return true; - -#if _MIPS_SIM == _ABIO32 - /* A special case arises for O32 FP64 and FP64A where the kernel - pre-dates PT_MIPS_ABIFLAGS. These ABIs will be blindly loaded even - if the hardware mode is unavailable or disabled. In this - circumstance the prctl call to obtain the current mode will fail. - Detect this situation here and reject everything. This will - effectively prevent dynamically linked applications from failing in - unusual ways but there is nothing we can do to help static - applications. */ - if ((l->l_mach.fpabi == Val_GNU_MIPS_ABI_FP_64A - || l->l_mach.fpabi == Val_GNU_MIPS_ABI_FP_64) - && cur_mode == -1) - REJECT (" found %s running in the wrong mode\n", - fpabi_string (l->l_mach.fpabi)); -#endif - - /* Found a perfect match, success. */ - perfect_match |= (in_abi == l->l_mach.fpabi); - - /* Unknown ABIs are rejected. */ - if (l->l_mach.fpabi != -1 && l->l_mach.fpabi > Val_GNU_MIPS_ABI_FP_MAX) - REJECT (" found unknown FP ABI: %u\n", l->l_mach.fpabi); - - existing_req = (l->l_mach.fpabi == -1 ? none_req - : reqs[l->l_mach.fpabi]); - - /* Merge requirements. */ - in_req.soft &= existing_req.soft; - in_req.single &= existing_req.single; - in_req.fr0 &= existing_req.fr0; - in_req.fr1 &= existing_req.fr1; - in_req.fre &= existing_req.fre; - - /* If there is at least one mode which is still usable then the new - object can be loaded. */ - if (in_req.single || in_req.soft || in_req.fr1 || in_req.fr0 - || in_req.fre) - { -#if _MIPS_SIM == _ABIO32 && HAVE_PRCTL_FP_MODE - /* Account for loaded ABIs which prohibit mode switching. */ - if (l->l_mach.fpabi == Val_GNU_MIPS_ABI_FP_XX) - cannot_mode_switch |= l->l_mach.odd_spreg; -#endif - } - else - REJECT (" uses %s, already loaded %s\n", - fpabi_string (in_abi), - fpabi_string (l->l_mach.fpabi)); - } - -#if _MIPS_SIM == _ABIO32 - /* At this point we know that the newly loaded object is compatible with all - existing objects but the hardware mode may not be correct. */ - if ((in_req.fr1 || in_req.fre || in_req.fr0) - && !perfect_match) - { - if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)) - _dl_debug_printf (" needs %s%s mode\n", in_req.fr0 ? "FR0 or " : "", - (in_req.fre && !in_req.fr1) ? "FRE" : "FR1"); - - /* If the PR_GET_FP_MODE is not supported then only FR0 is available. - If the overall requirements cannot be met by FR0 then reject the - object. */ - if (cur_mode == -1) - return !in_req.fr0; - -# if HAVE_PRCTL_FP_MODE - { - unsigned int fr1_mode = PR_FP_MODE_FR; - - /* It is not possible to change the mode of a thread which may be - executing FPXX code with odd-singles. If an FPXX object with - odd-singles is loaded then just check the current mode is OK. This - can be either the FR1 mode or FR0 if the requirements are met by - FR0. */ - if (cannot_mode_switch) - return (!(in_req.fre && cur_mode == (PR_FP_MODE_FR | PR_FP_MODE_FRE)) - && !(in_req.fr1 && cur_mode == PR_FP_MODE_FR) - && !(in_req.fr0 && cur_mode == 0)); - - /* If the overall requirements can be satisfied by FRE but not FR1 then - fr1_mode must become FRE. */ - if (in_req.fre && !in_req.fr1) - fr1_mode |= PR_FP_MODE_FRE; - - /* Set the new mode. Use fr1_mode if the requirements cannot be met by - FR0. */ - if (!in_req.fr0) - return __prctl (PR_SET_FP_MODE, fr1_mode) != 0; - else if (__prctl (PR_SET_FP_MODE, /* fr0_mode */ 0) != 0) - { - /* Setting FR0 can validly fail on an R6 core so retry with the FR1 - mode as a fall back. */ - if (errno != ENOTSUP) - return true; - - return __prctl (PR_SET_FP_MODE, fr1_mode) != 0; - } - } -# endif /* HAVE_PRCTL_FP_MODE */ - } -#endif /* _MIPS_SIM == _ABIO32 */ - - return false; -} - -#endif /* dl-machine-reject-phdr.h */ |