powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API

When creating a kprobe on function entry through tracefs, enable
arguments to be recorded to be specified using $argN syntax.

Signed-off-

powerpc/trace: Add support for HAVE_FUNCTION_ARG_ACCESS_API

When creating a kprobe on function entry through tracefs, enable
arguments to be recorded to be specified using $argN syntax.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230614085926.2176641-1-naveen@kernel.org

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powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid

Checks to see if the [H]SRR registers have been clobbered by (soft)
NMI interrupts imply the possibility for a data race on the
[h]srr_

powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid

Checks to see if the [H]SRR registers have been clobbered by (soft)
NMI interrupts imply the possibility for a data race on the
[h]srr_valid entries in the PACA. Annotate accesses to these fields with
READ_ONCE, removing the need for the barrier.

The diagnostic can use plain-access reads and writes, but annotate with
data_race.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-5-rmclure@linux.ibm.com

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powerpc: remove STACK_FRAME_OVERHEAD

This is equal to STACK_FRAME_MIN_SIZE on 32-bit and 64-bit ELFv1, and no
longer used in 64-bit ELFv2, so replace STACK_FRAME_OVERHEAD occurrences
with STACK_FRAM

powerpc: remove STACK_FRAME_OVERHEAD

This is equal to STACK_FRAME_MIN_SIZE on 32-bit and 64-bit ELFv1, and no
longer used in 64-bit ELFv2, so replace STACK_FRAME_OVERHEAD occurrences
with STACK_FRAME_MIN_SIZE.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-18-npiggin@gmail.com

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powerpc/64: ELFv2 use minimal stack frames in int and switch frame sizes

Adjust the ELFv2 interrupt and switch frames to the minimum C ABI size,
plus pt_regs, plus 16 bytes for the aligned regs mark

powerpc/64: ELFv2 use minimal stack frames in int and switch frame sizes

Adjust the ELFv2 interrupt and switch frames to the minimum C ABI size,
plus pt_regs, plus 16 bytes for the aligned regs marker for the int
frame (and the switch frame needs to match that because it uses the same
regs offset as the int frame).

This saves 80 bytes of kernel stack per interrupt. It's the principle of
getting our accounting right that's more important than the practical
saving.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-17-npiggin@gmail.com

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powerpc: add a define for the switch frame size and regs offset

This is open-coded in process.c, ppc32 uses a different define with the
same value, and the C definition is name differently which mak

powerpc: add a define for the switch frame size and regs offset

This is open-coded in process.c, ppc32 uses a different define with the
same value, and the C definition is name differently which makes it an
extra indirection to grep for.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-12-npiggin@gmail.com

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powerpc: add a define for the user interrupt frame size

The user interrupt frame is a different size from the kernel frame, so
give it its own name.

Signed-off-by: Nicholas Piggin <npiggin@gmail.co

powerpc: add a define for the user interrupt frame size

The user interrupt frame is a different size from the kernel frame, so
give it its own name.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-11-npiggin@gmail.com

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powerpc: Rename STACK_FRAME_MARKER and derive it from frame offset

This is a count of longs from the stack pointer to the regs marker.
Rename it to make it more distinct from the other byte offsets.

powerpc: Rename STACK_FRAME_MARKER and derive it from frame offset

This is a count of longs from the stack pointer to the regs marker.
Rename it to make it more distinct from the other byte offsets. It
can be derived from the byte offset definitions just added.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-10-npiggin@gmail.com

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powerpc: add a definition for the marker offset within the interrupt frame

Define a constant rather than open-code the offset for the
"regs" marker.

Signed-off-by: Nicholas Piggin <npiggin@gmail.co

powerpc: add a definition for the marker offset within the interrupt frame

Define a constant rather than open-code the offset for the
"regs" marker.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-9-npiggin@gmail.com

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powerpc: add definition for pt_regs offset within an interrupt frame

This is a common offset that currently uses the overloaded
STACK_FRAME_OVERHEAD constant. It's easier to read and more
flexible t

powerpc: add definition for pt_regs offset within an interrupt frame

This is a common offset that currently uses the overloaded
STACK_FRAME_OVERHEAD constant. It's easier to read and more
flexible to use a specific regs offset for this.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221127124942.1665522-8-npiggin@gmail.com

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powerpc: Reverse stack frame marker on little endian

On little endian the stack frame marker appears reversed when dumping
memory sequentially, as is typical in xmon or gdb, eg:

c000000004733e40

powerpc: Reverse stack frame marker on little endian

On little endian the stack frame marker appears reversed when dumping
memory sequentially, as is typical in xmon or gdb, eg:

c000000004733e40 0000000000000000 0000000000000000 |................|
c000000004733e50 0000000000000000 0000000000000000 |................|
c000000004733e60 0000000000000000 0000000000000000 |................|
c000000004733e70 5347455200000000 0000000000000000 |SGER............|
c000000004733e80 a700000000000000 708897f7ff7f0000 |........p.......|
c000000004733e90 0073428fff7f0000 208997f7ff7f0000 |.sB..... .......|
c000000004733ea0 0100000000000000 ffffffffffffffff |................|
c000000004733eb0 0000000000000000 0000000000000000 |................|

To make it easier to recognise, reverse the value on little endian, so
it always appears as "REGS", eg:

c000000004733e70 5245475300000000 0000000000000000 |REGS............|

Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220927150419.1503001-2-mpe@ellerman.id.au

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powerpc: Make stack frame marker upper case

Now that the stack frame regs marker is only 32-bits it is not as
obvious in memory dumps and easier to miss, eg:

c000000004733e40 0000000000000000 000

powerpc: Make stack frame marker upper case

Now that the stack frame regs marker is only 32-bits it is not as
obvious in memory dumps and easier to miss, eg:

c000000004733e40 0000000000000000 0000000000000000 |................|
c000000004733e50 0000000000000000 0000000000000000 |................|
c000000004733e60 0000000000000000 0000000000000000 |................|
c000000004733e70 7367657200000000 0000000000000000 |sger............|
c000000004733e80 a700000000000000 708897f7ff7f0000 |........p.......|
c000000004733e90 0073428fff7f0000 208997f7ff7f0000 |.sB..... .......|
c000000004733ea0 0100000000000000 ffffffffffffffff |................|
c000000004733eb0 0000000000000000 0000000000000000 |................|

So make it upper case to make it stand out a bit more:

c000000004733e70 5347455200000000 0000000000000000 |SGER............|

Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220927150419.1503001-1-mpe@ellerman.id.au

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powerpc/64: use 32-bit immediate for STACK_FRAME_REGS_MARKER

Using a 32-bit constant for this marker allows it to be loaded with
two ALU instructions, like 32-bit. This avoids a TOC entry and a
TOC

powerpc/64: use 32-bit immediate for STACK_FRAME_REGS_MARKER

Using a 32-bit constant for this marker allows it to be loaded with
two ALU instructions, like 32-bit. This avoids a TOC entry and a
TOC load that depends on the r2 value that has just been loaded from
the PACA.

This changes the value for 32-bit as well, so both have the same
value in the low 4 bytes and 64-bit has 0 in the top bytes.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220926034057.2360083-2-npiggin@gmail.com

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powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}

Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by
resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2.

Signed-of

powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}

Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by
resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu

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powerpc/config: Add CONFIG_BOOKE_OR_40x

We have many functionnalities common to 40x and BOOKE, it leads to
many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x).

We are going to add a f

powerpc/config: Add CONFIG_BOOKE_OR_40x

We have many functionnalities common to 40x and BOOKE, it leads to
many places with #if defined(CONFIG_BOOKE) || defined(CONFIG_40x).

We are going to add a few more with KUAP for booke/40x, so create
a new symbol which is defined when either BOOKE or 40x is defined.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9a3dbd60924cb25c9f944d3d8205ac5a0d15e229.1634627931.git.christophe.leroy@csgroup.eu

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powerpc: Refactor verification of MSR_RI

40x and BOOKE don't have MSR_RI therefore all tests involving
MSR_RI may be problematic on those plateforms.

Create helpers to check or set MSR_RI in regs,

powerpc: Refactor verification of MSR_RI

40x and BOOKE don't have MSR_RI therefore all tests involving
MSR_RI may be problematic on those plateforms.

Create helpers to check or set MSR_RI in regs, and use them
in common code.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c2fb93708196734f4176dda334aaa3055f213b89.1629707037.git.christophe.leroy@csgroup.eu

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powerpc: Add dear as a synonym for pt_regs.dar register

Create an anonymous union for dar and dear regsiters, we can reference
dear to get the effective address when CONFIG_4xx=y or CONFIG_BOOKE=y.

powerpc: Add dear as a synonym for pt_regs.dar register

Create an anonymous union for dar and dear regsiters, we can reference
dear to get the effective address when CONFIG_4xx=y or CONFIG_BOOKE=y.
Otherwise, reference dar. This makes code more clear.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
[mpe: Reword commit title]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210807010239.416055-4-sxwjean@me.com

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powerpc: Add esr as a synonym for pt_regs.dsisr

Create an anonymous union for dsisr and esr regsiters, we can reference
esr to get the exception detail when CONFIG_4xx=y or CONFIG_BOOKE=y.
Otherwise

powerpc: Add esr as a synonym for pt_regs.dsisr

Create an anonymous union for dsisr and esr regsiters, we can reference
esr to get the exception detail when CONFIG_4xx=y or CONFIG_BOOKE=y.
Otherwise, reference dsisr. This makes code more clear.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
[mpe: Reword commit title]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210807010239.416055-2-sxwjean@me.com

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powerpc/ptrace: Make user_mode() common to PPC32 and PPC64

Today we have:

#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
#define user_mode(regs) (((regs

powerpc/ptrace: Make user_mode() common to PPC32 and PPC64

Today we have:

#ifdef __powerpc64__
#define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
#else
#define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
#endif

With ppc64_defconfig, we get:

if (!user_mode(regs))
14b4: e9 3e 01 08 ld r9,264(r30)
14b8: 71 29 40 00 andi. r9,r9,16384
14bc: 41 82 07 a4 beq 1c60 <.emulate_instruction+0x7d0>

If taking the ppc32 definition of user_mode(), the exact same code
is generated for ppc64_defconfig.

So, only keep one version of user_mode(), preferably the one not
using MSR_PR_LG which should be kept internal to reg.h.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/000a28c51808bbd802b505af42d2cb316c2be7d3.1629216000.git.christophe.leroy@csgroup.eu

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powerpc/32: Fix critical and debug interrupts on BOOKE

32 bits BOOKE have special interrupts for debug and other
critical events.

When handling those interrupts, dedicated registers are saved
in th

powerpc/32: Fix critical and debug interrupts on BOOKE

32 bits BOOKE have special interrupts for debug and other
critical events.

When handling those interrupts, dedicated registers are saved
in the stack frame in addition to the standard registers, leading
to a shift of the pt_regs struct.

Since commit db297c3b07af ("powerpc/32: Don't save thread.regs on
interrupt entry"), the pt_regs struct is expected to be at the
same place all the time.

Instead of handling a special struct in addition to pt_regs, just
add those special registers to struct pt_regs.

Fixes: db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry")
Cc: stable@vger.kernel.org
Reported-by: Radu Rendec <radu.rendec@gmail.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/028d5483b4851b01ea4334d0751e7f260419092b.1625637264.git.christophe.leroy@csgroup.eu

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powerpc/ptrace: Refactor regs_set_return_{msr/ip}

regs_set_return_msr() and regs_set_return_ip() have a copy
of the code of set_return_regs_changed().

Call the later instead.

Signed-off-by: Christ

powerpc/ptrace: Refactor regs_set_return_{msr/ip}

regs_set_return_msr() and regs_set_return_ip() have a copy
of the code of set_return_regs_changed().

Call the later instead.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/baf64a91557d3811c155616a6aa23ed7b3b21da4.1624619582.git.christophe.leroy@csgroup.eu

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powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip}

regs_set_return_msr() and regs_set_return_ip() have a copy
of the code of set_return_regs_changed().

Move up set_retur

powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip}

regs_set_return_msr() and regs_set_return_ip() have a copy
of the code of set_return_regs_changed().

Move up set_return_regs_changed() so it can be reused by
regs_set_return_{msr/ip}

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/49f4fb051a3e1cb69f7305d5b6768aec14727c32.1624619582.git.christophe.leroy@csgroup.eu

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powerpc/64: use interrupt restart table to speed up return from interrupt

Use the restart table facility to return from interrupt or system calls
without disabling MSR[EE] or MSR[RI].

Interrupt ret

powerpc/64: use interrupt restart table to speed up return from interrupt

Use the restart table facility to return from interrupt or system calls
without disabling MSR[EE] or MSR[RI].

Interrupt return asm is put into the low soft-masked region, to prevent
interrupts being processed here, although they are still taken as masked
interrupts which causes SRRs to be clobbered, and a pending soft-masked
interrupt to require replaying.

The return code uses restart table regions to redirct to a fixup handler
rather than continue with the exit, if such an interrupt happens. In
this case the interrupt return is redirected to a fixup handler which
reloads r1 for the interrupt stack and reloads registers and sets state
up to replay the soft-masked interrupt and try the exit again.

Some types of security exit fallback flushes and barriers are currently
unable to cope with reentrant interrupts, e.g., because they store some
state in the scratch SPR which would be clobbered even by masked
interrupts. For now the interrupts-enabled exits are disabled when these
flushes are used.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Guard unused exit_must_hard_disable() as reported by lkp]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-13-npiggin@gmail.com

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powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime,

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

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powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls

The scv implementation missed updating syscall return value and error
value get/set functions to deal with the changed register ABI. Th

powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls

The scv implementation missed updating syscall return value and error
value get/set functions to deal with the changed register ABI. This
broke ptrace PTRACE_GET_SYSCALL_INFO as well as some kernel auditing
and tracing functions.

Fix. tools/testing/selftests/ptrace/get_syscall_info now passes when
scv is used.

Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@vger.kernel.org # v5.9+
Reported-by: "Dmitry V. Levin" <ldv@altlinux.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210520111931.2597127-2-npiggin@gmail.com

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powerpc: Only pad struct pt_regs when needed

If neither KUAP nor PPC64 is selected, there is nothing in the second
union of struct pt_regs, so the alignment padding is waste of memory.

Signed-off-b

powerpc: Only pad struct pt_regs when needed

If neither KUAP nor PPC64 is selected, there is nothing in the second
union of struct pt_regs, so the alignment padding is waste of memory.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d536bbc46094f66b24d3017343be25164f232933.1620307840.git.christophe.leroy@csgroup.eu

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