MIPS supports PC32 relocations like most other architectures, which will
be used by kallsyms to make its symbol references visible to the linker.
Given that these are place-relative, they can be ignored by the 'relocs'
tool, just like other PC type relocations.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://patch.msgid.link/20260116093359.2442297-5-ardb+git@google.com
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Like amd64, mips has two 32bit ABIs - o32 and n32. Unlike amd64,
it does not use compat_binfmt_elf.c for either of those; each
of those ABIs has a binfmt handler of its own, both very similar
to fs/compat_binfmt_elf.c. And the same technics as we use on
amd64 can be used to make fs/compat_binfmt_elf.c handle both.
* merge elfo32_check_arch() with elfn32_check_arch(),
make that serve as compat_elf_check_arch(). Note that
SET_PERSONALITY2() is already the same for all ABI variants -
it looks at the elf header to choose the flags to set.
* add asm/elfcore-compat.h, using the bigger (n32) variant
of elf32_prstatus as compat_elf_prstatus there.
* make PRSTATUS_SIZE() and SET_PR_FPVALID() choose the
right layout, same as done for amd64. test_thread_flag(TIF_32BIT_REGS)
is used as the predicate.
Voila - we are rid of binfmt_elf{n,o}32.c; fs/compat_binfmt_elf.c is
used, same as for all other ELF-supporting 64bit architectures that
need 32bit compat.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
normal mips one is just fine - it's only used after we'd done
SET_PERSONALITY2() and by that point TASK_SIZE will yield the
right value
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the MIPS architecture, we should clear the security-relevant
flag READ_IMPLIES_EXEC in the function SET_PERSONALITY2() of the
file arch/mips/include/asm/elf.h.
Otherwise, with this flag set, PROT_READ implies PROT_EXEC for
mmap to make memory executable that is not safe, because this
condition allows an attacker to simply jump to and execute bytes
that are considered to be just data [1].
In mm/mmap.c:
unsigned long do_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flags, vm_flags_t vm_flags,
unsigned long pgoff, unsigned long *populate,
struct list_head *uf)
{
[...]
if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
if (!(file && path_noexec(&file->f_path)))
prot |= PROT_EXEC;
[...]
}
By the way, x86 and ARM64 have done the similar thing.
After commit 250c22777f ("x86_64: move kernel"), in the file
arch/x86/kernel/process_64.c:
void set_personality_64bit(void)
{
[...]
current->personality &= ~READ_IMPLIES_EXEC;
}
After commit 48f99c8ec0 ("arm64: Preventing READ_IMPLIES_EXEC
propagation"), in the file arch/arm64/include/asm/elf.h:
#define SET_PERSONALITY(ex) \
({ \
clear_thread_flag(TIF_32BIT); \
current->personality &= ~READ_IMPLIES_EXEC; \
})
[1] https://insights.sei.cmu.edu/cert/2014/02/feeling-insecure-blame-your-parent.html
Reported-by: Juxin Gao <gaojuxin@loongson.cn>
Co-developed-by: Juxin Gao <gaojuxin@loongson.cn>
Signed-off-by: Juxin Gao <gaojuxin@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Some userland application/program runtime/dynamic loaded need to
know about the current ISA level to use the best runtime.
While kernel doesn't provides this info.
ELF_PLATFORM only provides some info about the CPU, with very few info,
for example, the value is "mips" for both 24Kc and P6600.
Currently ELF_BASE_PLATFORM is not used by MIPS (only by powerpc).
So we cant set its value as:
mips2, mips3, mips4, mips5,
mips32, mips32r2, mips32r6
mips64, mips64r2, mips64r6
Then in userland, we can get it by:
getauxval(AT_BASE_PLATFORM)
The only problem is that it seems has different defination than ppc:
on ppc, it is the mircoarchitecture
while now we use it as ISA level on MIPS.
Signed-off-by: YunQiang Su <syq@debian.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we can
avoid needless checks of ELF headers specifying the FP ABI or NaN
encoding to use. Deselect CONFIG_ARCH_BINFMT_ELF_STATE in this case to
avoid the need for our arch_elf_pt_proc() & arch_check_elf() functions,
and stub out the mips_set_personality_nan() & mips_set_personality_fp()
functions such that SET_PERSONALITY() doesn't need to worry about any of
this.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21011/
Cc: linux-mips@linux-mips.org
MIPS does not currently define ELF_CORE_COPY_REGS macros and as a result
the generic implementation is used. The generic version attempts to do
directly map (struct pt_regs) into (elf_gregset_t), which isn't correct
for MIPS platforms and also triggers a BUG() at runtime in
include/linux/elfcore.h:16 (BUG_ON(sizeof(*elfregs) != sizeof(*regs)))
[ralf@linux-mips.org: Add semicolons to the macro definitions as I do not
apply https://patchwork.linux-mips.org/patch/14588/ for now.]
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14586/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The stack and heap have both been executable by default on MIPS until
now. This patch changes the default to be non-executable, but only for
ELF binaries with a non-executable PT_GNU_STACK header present. This
does apply to both the heap & the stack, despite the name PT_GNU_STACK,
and this matches the behaviour of other architectures like ARM & x86.
Current MIPS toolchains do not produce the PT_GNU_STACK header, which
means that we can rely upon this patch not changing the behaviour of
existing binaries. The new default will only take effect for newly
compiled binaries once toolchains are updated to support PT_GNU_STACK,
and since those binaries are newly compiled they can be compiled
expecting the change in default behaviour. Again this matches the way in
which the ARM & x86 architectures handled their implementations of
non-executable memory.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13765/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
AT_VECTOR_SIZE_ARCH should be defined with the maximum number of
NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined
for MIPS at all even though ARCH_DLINFO will contain one NEW_AUX_ENT for
the VDSO address.
This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for
AT_BASE_PLATFORM which MIPS doesn't use, but lets define it now and add
the comment above ARCH_DLINFO as found in several other architectures to
remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to
date.
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13823/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Depending on the configuration either the 32 or 64 bit version of
elf_check_arch() is defined. parse_crash_elf{32|64}_headers() does
some basic verification of the ELF header via
vmcore_elf{32|64}_check_arch() which happen to map to elf_check_arch().
Since the implementation 32 and 64 bit version of elf_check_arch()
differ, we use the wrong type:
In file included from include/linux/elf.h:4:0,
from fs/proc/vmcore.c:13:
fs/proc/vmcore.c: In function 'parse_crash_elf64_headers':
>> arch/mips/include/asm/elf.h:228:23: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
struct elfhdr *__h = (hdr); \
^
include/linux/crash_dump.h:41:37: note: in expansion of macro 'elf_check_arch'
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
^
fs/proc/vmcore.c:1015:4: note: in expansion of macro 'vmcore_elf64_check_arch'
!vmcore_elf64_check_arch(&ehdr) ||
^
Therefore, we rather define vmcore_elf{32|64}_check_arch() as a
basic machine check and use it also in binfm_elf?32.c as well.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Suggested-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: Maciej W. Rozycki <macro@imgtec.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12529/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add an `ieee754=' kernel parameter to control IEEE Std 754 conformance
mode.
Use separate flags copied from the respective CPU feature flags, and
adjusted according to the conformance mode selected, to make binaries
requesting individual NaN encoding modes accepted or rejected as needed.
Update the initial setting for FCSR and, in the full FPU emulation mode,
its read-only mask accordingly. Accept the mode selection requested for
legacy processors as well.
As with the EF_MIPS_NAN2008 ELF file header flag adjust both ABS2008 and
NAN2008 bits at the same time, to match the choice made for hardware
currently implemented.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11481/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Handle the EF_MIPS_NAN2008 ELF file header flag and refuse execution
where there is no support in the FPU for the NaN encoding mode requested
by a binary invoked. Ensure that the setting of the bit in the binary
matches one in any intepreter used. Set the thread's initial FCSR
contents according to the value of the EF_MIPS_NAN2008.
Set the values of the FCSR ABS2008 and NAN2008 bits both to the same
value if possible, to take the approach taken with existing FPU hardware
into account. As of now all implementations have both bits hardwired to
the same value, that is both are fixed at 0 or both are fixed at 1, even
though the architecture allows for implementations where the amount of
control implemented with each of these two individual bits is
independent of each other.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11479/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add an initial implementation of a proper (i.e. an ELF shared library)
VDSO. With this commit it does not export any symbols, it only replaces
the current signal return trampoline page. A later commit will add user
implementations of gettimeofday()/clock_gettime().
To support both new toolchains and old ones which don't generate ABI
flags section, we define its content manually and then use a tool
(genvdso) to patch up the section to have the correct name and type.
genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the
kernel, and generates a C file containing a "struct mips_vdso_image"
containing both the VDSO data and these offsets. This C file is
compiled into the kernel.
On 64-bit kernels we require a different VDSO for each supported ABI,
so we may build up to 3 different VDSOs. The VDSO to use is selected by
the mips_abi structure.
A kernel/user shared data page is created and mapped below the VDSO
image. This is currently empty, but will be used by the user time
function implementations which are added later.
[markos.chandras@imgtec.com:
- Add more comments
- Move abi detection in genvdso.h since it's the get_symbol function
that needs it.
- Add an R6 specific way to calculate the base address of VDSO in order
to avoid the branch instruction which affects performance.
- Do not patch .gnu.attributes since it's not needed for dynamic linking.
- Simplify Makefile a little bit.
- checkpatch fixes
- Restrict VDSO support for binutils < 2.25 for pre-R6
- Include atomic64.h for O32 variant on MIPS64]
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11337/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix "BUG: using smp_processor_id() in preemptible" reported in accesses
to thread's FPU defaults: the value to initialise FSCR to at program
startup, the FCSR r/w mask and the contents of FIR in full FPU
emulation, removing a regression introduced with 9b26616c [MIPS: Respect
the ISA level in FCSR handling] and f6843626 [MIPS: math-emu: Set FIR
feature flags for full emulation].
Use `boot_cpu_data' to obtain the data from, following the approach that
`cpu_has_*' macros take and avoiding the call to `smp_processor_id' made
in the reference to `current_cpu_data'. The contents of FSCR have to be
consistent across processors in an SMP system, the settings there must
not change as a thread is migrated across processors. And the contents
of FIR are guaranteed to be consistent in FPU emulation, by definition.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Tested-by: Paul Martin <paul.martin@codethink.co.uk>
Cc: Markos Chandras <Markos.Chandras@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10030/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for Linux 4.1. Most
noteworthy:
- Add more Octeon-optimized crypto functions
- Octeon crypto preemption and locking fixes
- Little endian support for Octeon
- Use correct CSR to soft reset Octeons
- Support LEDs on the Octeon-based DSR-1000N
- Fix PCI interrupt mapping for the Octeon-based DSR-1000N
- Mark prom_free_prom_memory() as __init for a number of systems
- Support for Imagination's Pistachio SOC. This includes arch and
CLK bits. I'd like to merge pinctrl bits later
- Improve parallelism of csum_partial for certain pipelines
- Organize DTB files in subdirs like other architectures
- Implement read_sched_clock for all MIPS platforms other than
Octeon
- Massive series of 38 fixes and cleanups for the FPU emulator /
kernel
- Further FPU remulator work to support new features. This sits on a
separate branch which also has been pulled into the 4.1 KVM branch
- Clean up and fixes for the SEAD3 eval board; remove unused file
- Various updates for Netlogic platforms
- A number of small updates for Loongson 3 platforms
- Increase the memory limit for ATH79 platforms to 256MB
- A fair number of fixes and updates for BCM47xx platforms
- Finish the implementation of XPA support
- MIPS FDC support. No, not floppy controller but Fast Debug Channel :)
- Detect the R16000 used in SGI legacy platforms
- Fix Kconfig dependencies for the SSB bus support"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (265 commits)
MIPS: Makefile: Fix MIPS ASE detection code
MIPS: asm: elf: Set O32 default FPU flags
MIPS: BCM47XX: Fix detecting Microsoft MN-700 & Asus WL500G
MIPS: Kconfig: Disable SMP/CPS for 64-bit
MIPS: Hibernate: flush TLB entries earlier
MIPS: smp-cps: cpu_set FPU mask if FPU present
MIPS: lose_fpu(): Disable FPU when MSA enabled
MIPS: ralink: add missing symbol for RALINK_ILL_ACC
MIPS: ralink: Fix bad config symbol in PCI makefile.
SSB: fix Kconfig dependencies
MIPS: Malta: Detect and fix bad memsize values
Revert "MIPS: Avoid pipeline stalls on some MIPS32R2 cores."
MIPS: Octeon: Delete override of cpu_has_mips_r2_exec_hazard.
MIPS: Fix cpu_has_mips_r2_exec_hazard.
MIPS: kernel: entry.S: Set correct ISA level for mips_ihb
MIPS: asm: spinlock: Fix addiu instruction for R10000_LLSC_WAR case
MIPS: r4kcache: Use correct base register for MIPS R6 cache flushes
MIPS: Kconfig: Fix typo for the r2-to-r6 emulator kernel parameter
MIPS: unaligned: Fix regular load/store instruction emulation for EVA
MIPS: unaligned: Surround load/store macros in do {} while statements
...
