linux-stable.git/arch/mips, branch v6.6.26 Linux kernel stable tree MIPS: Clear Cause.BD in instruction_pointer_set 2024-03-26T22:19:10+00:00 Jiaxun Yang jiaxun.yang@flygoat.com 2024-02-02T12:30:27+00:00 ab63a80996d7ba33c759335444b18c3b54b46cb0 [ Upstream commit 9d6e21ddf20293b3880ae55b9d14de91c5891c59 ] Clear Cause.BD after we use instruction_pointer_set to override EPC. This can prevent exception_epc check against instruction code at new return address. It won't be considered as "in delay slot" after epc being overridden anyway. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9d6e21ddf20293b3880ae55b9d14de91c5891c59 ]

Clear Cause.BD after we use instruction_pointer_set to override
EPC.

This can prevent exception_epc check against instruction code at
new return address.
It won't be considered as "in delay slot" after epc being overridden
anyway.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
MIPS: reserve exception vector space ONLY ONCE 2024-03-01T12:34:50+00:00 Huang Pei huangpei@loongson.cn 2024-01-23T01:47:57+00:00 f778a45784d34355b481b16b8348374fa2e585eb [ Upstream commit abcabb9e30a1f9a69c76776f8abffc31c377b542 ] "cpu_probe" is called both by BP and APs, but reserving exception vector (like 0x0-0x1000) called by "cpu_probe" need once and calling on APs is too late since memblock is unavailable at that time. So, reserve exception vector ONLY by BP. Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Huang Pei <huangpei@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit abcabb9e30a1f9a69c76776f8abffc31c377b542 ]

"cpu_probe" is called both by BP and APs, but reserving exception vector
(like 0x0-0x1000) called by "cpu_probe" need once and calling on APs is
too late since memblock is unavailable at that time.

So, reserve exception vector ONLY by BP.

Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ptrace: Introduce exception_ip arch hook 2024-02-23T08:24:53+00:00 Jiaxun Yang jiaxun.yang@flygoat.com 2024-02-02T12:30:26+00:00 fdd12a80f64fbe68307619f3e83ed17e12118de3 [ Upstream commit 11ba1728be3edb6928791f4c622f154ebe228ae6 ] On architectures with delay slot, architecture level instruction pointer (or program counter) in pt_regs may differ from where exception was triggered. Introduce exception_ip hook to invoke architecture code and determine actual instruction pointer to the exception. Link: https://lore.kernel.org/lkml/00d1b813-c55f-4365-8d81-d70258e10b16@app.fastmail.com/ Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Stable-dep-of: 8fa507083388 ("mm/memory: Use exception ip to search exception tables") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 11ba1728be3edb6928791f4c622f154ebe228ae6 ]

On architectures with delay slot, architecture level instruction
pointer (or program counter) in pt_regs may differ from where
exception was triggered.

Introduce exception_ip hook to invoke architecture code and determine
actual instruction pointer to the exception.

Link: https://lore.kernel.org/lkml/00d1b813-c55f-4365-8d81-d70258e10b16@app.fastmail.com/
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Stable-dep-of: 8fa507083388 ("mm/memory: Use exception ip to search exception tables")
Signed-off-by: Sasha Levin <sashal@kernel.org>
MIPS: Add 'memory' clobber to csum_ipv6_magic() inline assembler 2024-02-23T08:24:53+00:00 Guenter Roeck linux@roeck-us.net 2024-02-11T16:08:37+00:00 2252913f156fffb0b5bec3a88e266104b69f3c9b [ Upstream commit d55347bfe4e66dce2e1e7501e5492f4af3e315f8 ] After 'lib: checksum: Use aligned accesses for ip_fast_csum and csum_ipv6_magic tests' was applied, the test_csum_ipv6_magic unit test started failing for all mips platforms, both little and bit endian. Oddly enough, adding debug code into test_csum_ipv6_magic() made the problem disappear. The gcc manual says: "The "memory" clobber tells the compiler that the assembly code performs memory reads or writes to items other than those listed in the input and output operands (for example, accessing the memory pointed to by one of the input parameters) " This is definitely the case for csum_ipv6_magic(). Indeed, adding the 'memory' clobber fixes the problem. Cc: Charlie Jenkins <charlie@rivosinc.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit d55347bfe4e66dce2e1e7501e5492f4af3e315f8 ]

After 'lib: checksum: Use aligned accesses for ip_fast_csum and
csum_ipv6_magic tests' was applied, the test_csum_ipv6_magic unit test
started failing for all mips platforms, both little and bit endian.
Oddly enough, adding debug code into test_csum_ipv6_magic() made the
problem disappear.

The gcc manual says:

"The "memory" clobber tells the compiler that the assembly code performs
 memory reads or writes to items other than those listed in the input
 and output operands (for example, accessing the memory pointed to by one
 of the input parameters)
"

This is definitely the case for csum_ipv6_magic(). Indeed, adding the
'memory' clobber fixes the problem.

Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
work around gcc bugs with 'asm goto' with outputs 2024-02-23T08:24:47+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-02-09T20:39:31+00:00 aaff74d886d08d0708f8d316ef09b5b4bd9dd7c1 commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream. We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. but the same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Andrew Pinski <quic_apinski@quicinc.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4356e9f841f7fbb945521cef3577ba394c65f3fc upstream.

We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f53 ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422

     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: Introduce flush_cache_vmap_early() 2024-02-16T18:10:52+00:00 Alexandre Ghiti alexghiti@rivosinc.com 2023-12-12T21:34:56+00:00 c4a05cf0ed782588cb3a2d9b2f5b539027108d06 [ Upstream commit 7a92fc8b4d20680e4c20289a670d8fca2d1f2c1b ] The pcpu setup when using the page allocator sets up a new vmalloc mapping very early in the boot process, so early that it cannot use the flush_cache_vmap() function which may depend on structures not yet initialized (for example in riscv, we currently send an IPI to flush other cpus TLB). But on some architectures, we must call flush_cache_vmap(): for example, in riscv, some uarchs can cache invalid TLB entries so we need to flush the new established mapping to avoid taking an exception. So fix this by introducing a new function flush_cache_vmap_early() which is called right after setting the new page table entry and before accessing this new mapping. This new function implements a local flush tlb on riscv and is no-op for other architectures (same as today). Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dennis Zhou <dennis@kernel.org> Stable-dep-of: d9807d60c145 ("riscv: mm: execute local TLB flush after populating vmemmap") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7a92fc8b4d20680e4c20289a670d8fca2d1f2c1b ]

The pcpu setup when using the page allocator sets up a new vmalloc
mapping very early in the boot process, so early that it cannot use the
flush_cache_vmap() function which may depend on structures not yet
initialized (for example in riscv, we currently send an IPI to flush
other cpus TLB).

But on some architectures, we must call flush_cache_vmap(): for example,
in riscv, some uarchs can cache invalid TLB entries so we need to flush
the new established mapping to avoid taking an exception.

So fix this by introducing a new function flush_cache_vmap_early() which
is called right after setting the new page table entry and before
accessing this new mapping. This new function implements a local flush
tlb on riscv and is no-op for other architectures (same as today).

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Stable-dep-of: d9807d60c145 ("riscv: mm: execute local TLB flush after populating vmemmap")
Signed-off-by: Sasha Levin <sashal@kernel.org>
mips: Call lose_fpu(0) before initializing fcr31 in mips_set_personality_nan 2024-02-01T00:19:13+00:00 Xi Ruoyao xry111@xry111.site 2024-01-26T21:05:57+00:00 33f49a68352dcd15b7b32ee5c3e954cad7bb21f6 commit 59be5c35850171e307ca5d3d703ee9ff4096b948 upstream. If we still own the FPU after initializing fcr31, when we are preempted the dirty value in the FPU will be read out and stored into fcr31, clobbering our setting. This can cause an improper floating-point environment after execve(). For example: zsh% cat measure.c #include <fenv.h> int main() { return fetestexcept(FE_INEXACT); } zsh% cc measure.c -o measure -lm zsh% echo $((1.0/3)) # raising FE_INEXACT 0.33333333333333331 zsh% while ./measure; do ; done (stopped in seconds) Call lose_fpu(0) before setting fcr31 to prevent this. Closes: https://lore.kernel.org/linux-mips/7a6aa1bbdbbe2e63ae96ff163fab0349f58f1b9e.camel@xry111.site/ Fixes: 9b26616c8d9d ("MIPS: Respect the ISA level in FCSR handling") Cc: stable@vger.kernel.org Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 59be5c35850171e307ca5d3d703ee9ff4096b948 upstream.

If we still own the FPU after initializing fcr31, when we are preempted
the dirty value in the FPU will be read out and stored into fcr31,
clobbering our setting.  This can cause an improper floating-point
environment after execve().  For example:

    zsh% cat measure.c
    #include <fenv.h>
    int main() { return fetestexcept(FE_INEXACT); }
    zsh% cc measure.c -o measure -lm
    zsh% echo $((1.0/3)) # raising FE_INEXACT
    0.33333333333333331
    zsh% while ./measure; do ; done
    (stopped in seconds)

Call lose_fpu(0) before setting fcr31 to prevent this.

Closes: https://lore.kernel.org/linux-mips/7a6aa1bbdbbe2e63ae96ff163fab0349f58f1b9e.camel@xry111.site/
Fixes: 9b26616c8d9d ("MIPS: Respect the ISA level in FCSR handling")
Cc: stable@vger.kernel.org
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: lantiq: register smp_ops on non-smp platforms 2024-02-01T00:19:13+00:00 Aleksander Jan Bajkowski olek2@wp.pl 2024-01-22T18:47:09+00:00 d21fbe290c3339324a8611be2889508fab37a73a [ Upstream commit 4bf2a626dc4bb46f0754d8ac02ec8584ff114ad5 ] Lantiq uses a common kernel config for devices with 24Kc and 34Kc cores. The changes made previously to add support for interrupts on all cores work on 24Kc platforms with SMP disabled and 34Kc platforms with SMP enabled. This patch fixes boot issues on Danube (single core 24Kc) with SMP enabled. Fixes: 730320fd770d ("MIPS: lantiq: enable all hardware interrupts on second VPE") Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4bf2a626dc4bb46f0754d8ac02ec8584ff114ad5 ]

Lantiq uses a common kernel config for devices with 24Kc and 34Kc cores.
The changes made previously to add support for interrupts on all cores
work on 24Kc platforms with SMP disabled and 34Kc platforms with SMP
enabled. This patch fixes boot issues on Danube (single core 24Kc) with
SMP enabled.

Fixes: 730320fd770d ("MIPS: lantiq: enable all hardware interrupts on second VPE")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mips: Fix max_mapnr being uninitialized on early stages 2024-02-01T00:18:52+00:00 Serge Semin fancer.lancer@gmail.com 2023-12-02T11:14:20+00:00 4a5a77c92bac9f1e90e6c360bb6b5e71b004ef7f commit e1a9ae45736989c972a8d1c151bc390678ae6205 upstream. max_mapnr variable is utilized in the pfn_valid() method in order to determine the upper PFN space boundary. Having it uninitialized effectively makes any PFN passed to that method invalid. That in its turn causes the kernel mm-subsystem occasion malfunctions even after the max_mapnr variable is actually properly updated. For instance, pfn_valid() is called in the init_unavailable_range() method in the framework of the calls-chain on MIPS: setup_arch() +-> paging_init() +-> free_area_init() +-> memmap_init() +-> memmap_init_zone_range() +-> init_unavailable_range() Since pfn_valid() always returns "false" value before max_mapnr is initialized in the mem_init() method, any flatmem page-holes will be left in the poisoned/uninitialized state including the IO-memory pages. Thus any further attempts to map/remap the IO-memory by using MMU may fail. In particular it happened in my case on attempt to map the SRAM region. The kernel bootup procedure just crashed on the unhandled unaligned access bug raised in the __update_cache() method: > Unhandled kernel unaligned access[#1]: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc1-XXX-dirty #2056 > ... > Call Trace: > [<8011ef9c>] __update_cache+0x88/0x1bc > [<80385944>] ioremap_page_range+0x110/0x2a4 > [<80126948>] ioremap_prot+0x17c/0x1f4 > [<80711b80>] __devm_ioremap+0x8c/0x120 > [<80711e0c>] __devm_ioremap_resource+0xf4/0x218 > [<808bf244>] sram_probe+0x4f4/0x930 > [<80889d20>] platform_probe+0x68/0xec > ... Let's fix the problem by initializing the max_mapnr variable as soon as the required data is available. In particular it can be done right in the paging_init() method before free_area_init() is called since all the PFN zone boundaries have already been calculated by that time. Cc: stable@vger.kernel.org Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e1a9ae45736989c972a8d1c151bc390678ae6205 upstream.

max_mapnr variable is utilized in the pfn_valid() method in order to
determine the upper PFN space boundary. Having it uninitialized
effectively makes any PFN passed to that method invalid. That in its turn
causes the kernel mm-subsystem occasion malfunctions even after the
max_mapnr variable is actually properly updated. For instance,
pfn_valid() is called in the init_unavailable_range() method in the
framework of the calls-chain on MIPS:
setup_arch()
+-> paging_init()
    +-> free_area_init()
        +-> memmap_init()
            +-> memmap_init_zone_range()
                +-> init_unavailable_range()

Since pfn_valid() always returns "false" value before max_mapnr is
initialized in the mem_init() method, any flatmem page-holes will be left
in the poisoned/uninitialized state including the IO-memory pages. Thus
any further attempts to map/remap the IO-memory by using MMU may fail.
In particular it happened in my case on attempt to map the SRAM region.
The kernel bootup procedure just crashed on the unhandled unaligned access
bug raised in the __update_cache() method:

> Unhandled kernel unaligned access[#1]:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc1-XXX-dirty #2056
> ...
> Call Trace:
> [<8011ef9c>] __update_cache+0x88/0x1bc
> [<80385944>] ioremap_page_range+0x110/0x2a4
> [<80126948>] ioremap_prot+0x17c/0x1f4
> [<80711b80>] __devm_ioremap+0x8c/0x120
> [<80711e0c>] __devm_ioremap_resource+0xf4/0x218
> [<808bf244>] sram_probe+0x4f4/0x930
> [<80889d20>] platform_probe+0x68/0xec
> ...

Let's fix the problem by initializing the max_mapnr variable as soon as
the required data is available. In particular it can be done right in the
paging_init() method before free_area_init() is called since all the PFN
zone boundaries have already been calculated by that time.

Cc: stable@vger.kernel.org
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: Alchemy: Fix an out-of-bound access in db1550_dev_setup() 2024-01-25T23:35:50+00:00 Christophe JAILLET christophe.jaillet@wanadoo.fr 2024-01-10T18:09:46+00:00 69bec5f534caac2d59d2146b5042d18688616eee [ Upstream commit 3c1e5abcda64bed0c7bffa65af2316995f269a61 ] When calling spi_register_board_info(), Fixes: f869d42e580f ("MIPS: Alchemy: Improved DB1550 support, with audio and serial busses.") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3c1e5abcda64bed0c7bffa65af2316995f269a61 ]

When calling spi_register_board_info(),

Fixes: f869d42e580f ("MIPS: Alchemy: Improved DB1550 support, with audio and serial busses.")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>