powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is ena

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:

ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484

With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.

Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.

Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is ena

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:

ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484

With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.

Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.

Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is ena

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:

ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484

With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.

Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.

Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is ena

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:

ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484

With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.

Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.

Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is ena

powerpc/ftrace: Ignore ftrace locations in exit text sections

commit ea73179e64131bcd29ba6defd33732abdf8ca14b upstream.

Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:

ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484

With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.

Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.

Fixes: 0f71dcfb4aef ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

powerpc/ftrace: Extend ftrace support for large kernels to ppc32

Commit 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs")
added ftrace support for ppc64 kernel images with a text sectio

powerpc/ftrace: Extend ftrace support for large kernels to ppc32

Commit 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs")
added ftrace support for ppc64 kernel images with a text section larger
than 32MB. The approach itself isn't specific to ppc64, so extend the
same to also work on ppc32.

While at it, reduce the space reserved for the stub from 64 bytes to 32
bytes since the different stub variants are all less than 8
instructions.

To reduce use of #ifdef, a stub implementation is provided for
kernel_toc_address() and -SZ_2G is cast to 'long long' to prevent
errors on ppc32.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/9fa3258cbb9105cf8a0a8135214d44ffbc75fe84.1687166935.git.naveen@kernel.org

show more ...

powerpc/64: vmlinux support building with PCREL addresing

PC-Relative or PCREL addressing is an extension to the ELF ABI which
uses Power ISA v3.1 PC-relative instructions to calculate addresses,
ra

powerpc/64: vmlinux support building with PCREL addresing

PC-Relative or PCREL addressing is an extension to the ELF ABI which
uses Power ISA v3.1 PC-relative instructions to calculate addresses,
rather than the traditional TOC scheme.

Add an option to build vmlinux using pcrel addressing. Modules continue
to use TOC addressing.

- TOC address helpers and r2 are poisoned with -1 when running vmlinux.
r2 could be used for something useful once things are ironed out.

- Assembly must call C functions with @notoc annotation, or the linker
complains aobut a missing nop after the call. This is done with the
CFUNC macro introduced earlier.

- Boot: with the exception of prom_init, the execution branches to the
kernel virtual address early in boot, before any addresses are
generated, which ensures 34-bit pcrel addressing does not miss the
high PAGE_OFFSET bits. TOC relative addressing has a similar
requirement. prom_init does not go to the virtual address and its
addresses should not carry over to the post-prom kernel.

- Ftrace trampolines are converted from TOC addressing to pcrel
addressing, including module ftrace trampolines that currently use the
kernel TOC to find ftrace target functions.

- BPF function prologue and function calling generation are converted
from TOC to pcrel.

- copypage_64.S has an interesting problem, prefixed instructions have
alignment restrictions so the linker can add padding, which makes the
assembler treat the difference between two local labels as
non-constant even if alignment is arranged so padding is not required.
This may need toolchain help to solve nicely, for now move the prefix
instruction out of the alternate patch section to work around it.

This reduces kernel text size by about 6%.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-6-npiggin@gmail.com

show more ...

powerpc/vmlinux.lds: Add .text.asan/tsan sections

When KASAN/KCSAN are enabled clang generates .text.asan/tsan sections.
Because they are not mentioned in the linker script warnings are
generated, a

powerpc/vmlinux.lds: Add .text.asan/tsan sections

When KASAN/KCSAN are enabled clang generates .text.asan/tsan sections.
Because they are not mentioned in the linker script warnings are
generated, and when orphan handling is set to error that becomes a build
error, eg:

ld.lld: error: vmlinux.a(init/main.o):(.text.tsan.module_ctor) is
being placed in '.text.tsan.module_ctor' ld.lld: error:
vmlinux.a(init/version.o):(.text.tsan.module_ctor) is being placed in
'.text.tsan.module_ctor'

Fix it by adding the sections to our linker script, similar to the
generic change made in 848378812e40 ("vmlinux.lds.h: Handle clang's
module.{c,d}tor sections").

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230222060037.2897169-1-mpe@ellerman.id.au

show more ...

objtool/idle: Validate __cpuidle code as noinstr

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infra

objtool/idle: Validate __cpuidle code as noinstr

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org

show more ...

powerpc/vmlinux.lds: Don't discard .comment

Although the powerpc linker script mentions .comment in the DISCARD
section, that has never actually caused it to be discarded, because the
earlier ELF_DE

powerpc/vmlinux.lds: Don't discard .comment

Although the powerpc linker script mentions .comment in the DISCARD
section, that has never actually caused it to be discarded, because the
earlier ELF_DETAILS macro (previously STABS_DEBUG) explicitly includes
.comment.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro. With binutils < 2.36 that causes the DISCARD directives later in
the script to be applied earlier, causing .comment to actually be
discarded.

It's confusing to explicitly include and discard .comment, and even more
so if the behaviour depends on the toolchain version. So don't discard
.comment in order to maintain the existing behaviour in all cases.

Fixes: 83a092cf95f2 ("powerpc: Link warning for orphan sections")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230105132349.384666-3-mpe@ellerman.id.au

show more ...

powerpc/vmlinux.lds: Don't discard .rela* for relocatable builds

Relocatable kernels must not discard relocations, they need to be
processed at runtime. As such they are included for CONFIG_RELOCATA

powerpc/vmlinux.lds: Don't discard .rela* for relocatable builds

Relocatable kernels must not discard relocations, they need to be
processed at runtime. As such they are included for CONFIG_RELOCATABLE
builds in the powerpc linker script (line 340).

However they are also unconditionally discarded later in the
script (line 414). Previously that worked because the earlier inclusion
superseded the discard.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 137). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier, causing .rela* to
actually be discarded at link time, leading to build warnings and a
kernel that doesn't boot:

ld: warning: discarding dynamic section .rela.init.rodata

Fix it by conditionally discarding .rela* only when CONFIG_RELOCATABLE
is disabled.

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20230105132349.384666-2-mpe@ellerman.id.au

show more ...

powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT

The powerpc linker script explicitly includes .exit.text, because
otherwise the link fails due to references from __bug_table and
__ex_table. The cod

powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT

The powerpc linker script explicitly includes .exit.text, because
otherwise the link fails due to references from __bug_table and
__ex_table. The code is freed (discarded) at runtime along with
.init.text and data.

That has worked in the past despite powerpc not defining
RUNTIME_DISCARD_EXIT because DISCARDS appears late in the powerpc linker
script (line 410), and the explicit inclusion of .exit.text
earlier (line 280) supersedes the discard.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 136). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier [1], causing
.exit.text to actually be discarded at link time, leading to build
errors:

'.exit.text' referenced in section '__bug_table' of crypto/algboss.o: defined in
discarded section '.exit.text' of crypto/algboss.o
'.exit.text' referenced in section '__ex_table' of drivers/nvdimm/core.o: defined in
discarded section '.exit.text' of drivers/nvdimm/core.o

Fix it by defining RUNTIME_DISCARD_EXIT, which causes the generic
DISCARDS macro to not include .exit.text at all.

1: https://lore.kernel.org/lkml/87fscp2v7k.fsf@igel.home/

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230105132349.384666-1-mpe@ellerman.id.au

show more ...

powerpc: Fix writable sections being moved into the rodata region

.data.rel.ro* catches .data.rel.root_cpuacct, and the kernel crashes on
a store in css_clear_dir. At least we know read-only data p

powerpc: Fix writable sections being moved into the rodata region

.data.rel.ro* catches .data.rel.root_cpuacct, and the kernel crashes on
a store in css_clear_dir. At least we know read-only data protection is
working...

Fixes: b6adc6d6d3272 ("powerpc/build: move .data.rel.ro, .sdata2 to read-only")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221116043954.3307852-1-npiggin@gmail.com

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powerpc: Drops STABS_DEBUG from linker scripts

No toolchain we support should be generating stabs debug information
anymore. Drop the sections entirely from our linker scripts.

We removed all the m

powerpc: Drops STABS_DEBUG from linker scripts

No toolchain we support should be generating stabs debug information
anymore. Drop the sections entirely from our linker scripts.

We removed all the manual stabs annotations in commit
12318163737c ("powerpc/32: Remove remaining .stabs annotations").

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220928130951.1732983-1-mpe@ellerman.id.au

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powerpc: Remove CONFIG_PPC_FSL_BOOK3E

CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500.

Remove it.

And rename five files accordingly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgr

powerpc: Remove CONFIG_PPC_FSL_BOOK3E

CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500.

Remove it.

And rename five files accordingly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Rename include guards to match new file names]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu

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powerpc: Remove CONFIG_PPC_BOOK3E

CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64.

The later is more explicit about the fact that it's a 64 bits target.

Remove CONFIG_PPC_BOOK3E.

Signed-

powerpc: Remove CONFIG_PPC_BOOK3E

CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64.

The later is more explicit about the fact that it's a 64 bits target.

Remove CONFIG_PPC_BOOK3E.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5d0891490813c19cdcfc04678f512ea68cba3e64.1663606876.git.christophe.leroy@csgroup.eu

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powerpc/64/build: merge .got and .toc input sections

Follow the binutils ld internal linker script and merge .got and .toc
input sections in the .got output section.

Signed-off-by: Nicholas Piggin

powerpc/64/build: merge .got and .toc input sections

Follow the binutils ld internal linker script and merge .got and .toc
input sections in the .got output section.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-7-npiggin@gmail.com

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powerpc/64/build: only include .opd with ELFv1

ELFv2 does not use function descriptors so .opd is not required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <m

powerpc/64/build: only include .opd with ELFv1

ELFv2 does not use function descriptors so .opd is not required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-6-npiggin@gmail.com

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powerpc/build: move .data.rel.ro, .sdata2 to read-only

.sdata2 is a readonly small data section for ppc32, and .data.rel.ro
is data that needs relocating but is read-only after that so these
can bot

powerpc/build: move .data.rel.ro, .sdata2 to read-only

.sdata2 is a readonly small data section for ppc32, and .data.rel.ro
is data that needs relocating but is read-only after that so these
can both be moved to the read only memory region.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-5-npiggin@gmail.com

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powerpc/build: move got, toc, plt, branch_lt sections to read-only

This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protec

powerpc/build: move got, toc, plt, branch_lt sections to read-only

This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protected,
after which there should be no modifications required.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Don't use SPECIAL as reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-4-npiggin@gmail.com

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powerpc/32/build: move got1/got2 sections out of text

Following the example from the binutils default linker script, move
.got1 and .got2 out of .text, to just after RO_DATA.

Signed-off-by: Nichola

powerpc/32/build: move got1/got2 sections out of text

Following the example from the binutils default linker script, move
.got1 and .got2 out of .text, to just after RO_DATA.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-3-npiggin@gmail.com

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powerpc: move __end_rodata to cover arch read-only sections

powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.

powerpc: move __end_rodata to cover arch read-only sections

powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.

Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.

This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com

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powerpc/vmlinux.lds: Add an explicit symbol for the SRWX boundary

Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after

powerpc/vmlinux.lds: Add an explicit symbol for the SRWX boundary

Currently __init_begin is used as the boundary for strict RWX between
executable/read-only text and data, and non-executable (after boot) code
and data.

But that's a little subtle, so add an explicit symbol to document that
the SRWX boundary lies there, and add a comment making it clear that
__init_begin must also begin there.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-2-mpe@ellerman.id.au

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powerpc/vmlinux.lds: Ensure STRICT_ALIGN_SIZE is at least page aligned

Add a check that STRICT_ALIGN_SIZE is aligned to at least PAGE_SIZE.

That then makes the alignment to PAGE_SIZE immediately af

powerpc/vmlinux.lds: Ensure STRICT_ALIGN_SIZE is at least page aligned

Add a check that STRICT_ALIGN_SIZE is aligned to at least PAGE_SIZE.

That then makes the alignment to PAGE_SIZE immediately after the
alignment to STRICT_ALIGN_SIZE redundant, so remove it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916131422.318752-1-mpe@ellerman.id.au

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powerpc/64: Remove unused prom_init_toc symbols

Commit 24d33ac5b8ff ("powerpc/64s: Make prom_init require RELOCATABLE")
made prom_init depend on CONFIG_RELOCATABLE.

But it missed cleaning up a case

powerpc/64: Remove unused prom_init_toc symbols

Commit 24d33ac5b8ff ("powerpc/64s: Make prom_init require RELOCATABLE")
made prom_init depend on CONFIG_RELOCATABLE.

But it missed cleaning up a case in the linker script for RELOCATABLE=n,
and associated symbols. Remove them now.

Fixes: 24d33ac5b8ff ("powerpc/64s: Make prom_init require RELOCATABLE")
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220920131157.1032707-1-mpe@ellerman.id.au

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