linux.git/arch/arm64/kernel/module-plts.c, branch v6.8 Linux kernel source tree Merge branch 'for-next/cpus_have_const_cap' into for-next/core 2023-10-26T16:10:18+00:00 Catalin Marinas catalin.marinas@arm.com 2023-10-26T16:10:18+00:00 14dcf78a6c042dd9421b11485b394c6273568bca * for-next/cpus_have_const_cap: (38 commits) : cpus_have_const_cap() removal arm64: Remove cpus_have_const_cap() arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_REPEAT_TLBI arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_NVIDIA_CARMEL_CNP arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_CAVIUM_23154 arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_2645198 arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1742098 arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1542419 arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_843419 arm64: Avoid cpus_have_const_cap() for ARM64_UNMAP_KERNEL_AT_EL0 arm64: Avoid cpus_have_const_cap() for ARM64_{SVE,SME,SME2,FA64} arm64: Avoid cpus_have_const_cap() for ARM64_SPECTRE_V2 arm64: Avoid cpus_have_const_cap() for ARM64_SSBS arm64: Avoid cpus_have_const_cap() for ARM64_MTE arm64: Avoid cpus_have_const_cap() for ARM64_HAS_TLB_RANGE arm64: Avoid cpus_have_const_cap() for ARM64_HAS_WFXT arm64: Avoid cpus_have_const_cap() for ARM64_HAS_RNG arm64: Avoid cpus_have_const_cap() for ARM64_HAS_EPAN arm64: Avoid cpus_have_const_cap() for ARM64_HAS_PAN arm64: Avoid cpus_have_const_cap() for ARM64_HAS_GIC_PRIO_MASKING arm64: Avoid cpus_have_const_cap() for ARM64_HAS_DIT ... 
* for-next/cpus_have_const_cap: (38 commits)
  : cpus_have_const_cap() removal
  arm64: Remove cpus_have_const_cap()
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_REPEAT_TLBI
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_NVIDIA_CARMEL_CNP
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_CAVIUM_23154
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_2645198
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1742098
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_1542419
  arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_843419
  arm64: Avoid cpus_have_const_cap() for ARM64_UNMAP_KERNEL_AT_EL0
  arm64: Avoid cpus_have_const_cap() for ARM64_{SVE,SME,SME2,FA64}
  arm64: Avoid cpus_have_const_cap() for ARM64_SPECTRE_V2
  arm64: Avoid cpus_have_const_cap() for ARM64_SSBS
  arm64: Avoid cpus_have_const_cap() for ARM64_MTE
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_TLB_RANGE
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_WFXT
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_RNG
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_EPAN
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_PAN
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_GIC_PRIO_MASKING
  arm64: Avoid cpus_have_const_cap() for ARM64_HAS_DIT
  ...
arm64: module: Fix PLT counting when CONFIG_RANDOMIZE_BASE=n 2023-10-24T14:12:48+00:00 Maria Yu quic_aiquny@quicinc.com 2023-10-24T01:09:54+00:00 d35686444fc80950c731e33a2f6ad4a55822be9b The counting of module PLTs has been broken when CONFIG_RANDOMIZE_BASE=n since commit: 3e35d303ab7d22c4 ("arm64: module: rework module VA range selection") Prior to that commit, when CONFIG_RANDOMIZE_BASE=n, the kernel image and all modules were placed within a 128M region, and no PLTs were necessary for B or BL. Hence count_plts() and partition_branch_plt_relas() skipped handling B and BL when CONFIG_RANDOMIZE_BASE=n. After that commit, modules can be placed anywhere within a 2G window regardless of CONFIG_RANDOMIZE_BASE, and hence PLTs may be necessary for B and BL even when CONFIG_RANDOMIZE_BASE=n. Unfortunately that commit failed to update count_plts() and partition_branch_plt_relas() accordingly. Due to this, module_emit_plt_entry() may fail if an insufficient number of PLT entries have been reserved, resulting in modules failing to load with -ENOEXEC. Fix this by counting PLTs regardless of CONFIG_RANDOMIZE_BASE in count_plts() and partition_branch_plt_relas(). Fixes: 3e35d303ab7d ("arm64: module: rework module VA range selection") Signed-off-by: Maria Yu <quic_aiquny@quicinc.com> Cc: <stable@vger.kernel.org> # 6.5.x Acked-by: Ard Biesheuvel <ardb@kernel.org> Fixes: 3e35d303ab7d ("arm64: module: rework module VA range selection") Reviewed-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20231024010954.6768-1-quic_aiquny@quicinc.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
The counting of module PLTs has been broken when CONFIG_RANDOMIZE_BASE=n
since commit:

  3e35d303ab7d22c4 ("arm64: module: rework module VA range selection")

Prior to that commit, when CONFIG_RANDOMIZE_BASE=n, the kernel image and
all modules were placed within a 128M region, and no PLTs were necessary
for B or BL. Hence count_plts() and partition_branch_plt_relas() skipped
handling B and BL when CONFIG_RANDOMIZE_BASE=n.

After that commit, modules can be placed anywhere within a 2G window
regardless of CONFIG_RANDOMIZE_BASE, and hence PLTs may be necessary for
B and BL even when CONFIG_RANDOMIZE_BASE=n. Unfortunately that commit
failed to update count_plts() and partition_branch_plt_relas()
accordingly.

Due to this, module_emit_plt_entry() may fail if an insufficient number
of PLT entries have been reserved, resulting in modules failing to load
with -ENOEXEC.

Fix this by counting PLTs regardless of CONFIG_RANDOMIZE_BASE in
count_plts() and partition_branch_plt_relas().

Fixes: 3e35d303ab7d ("arm64: module: rework module VA range selection")
Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>
Cc: <stable@vger.kernel.org> # 6.5.x
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Fixes: 3e35d303ab7d ("arm64: module: rework module VA range selection")
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231024010954.6768-1-quic_aiquny@quicinc.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: Avoid cpus_have_const_cap() for ARM64_WORKAROUND_843419 2023-10-16T13:17:06+00:00 Mark Rutland mark.rutland@arm.com 2023-10-16T10:24:54+00:00 0a285dfe875d5206da10c3d00564727f9482a9dd In count_plts() and is_forbidden_offset_for_adrp() we use cpus_have_const_cap() to check for ARM64_WORKAROUND_843419, but this is not necessary and cpus_have_final_cap() would be preferable. For historical reasons, cpus_have_const_cap() is more complicated than it needs to be. Before cpucaps are finalized, it will perform a bitmap test of the system_cpucaps bitmap, and once cpucaps are finalized it will use an alternative branch. This used to be necessary to handle some race conditions in the window between cpucap detection and the subsequent patching of alternatives and static branches, where different branches could be out-of-sync with one another (or w.r.t. alternative sequences). Now that we use alternative branches instead of static branches, these are all patched atomically w.r.t. one another, and there are only a handful of cases that need special care in the window between cpucap detection and alternative patching. Due to the above, it would be nice to remove cpus_have_const_cap(), and migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(), or cpus_have_cap() depending on when their requirements. This will remove redundant instructions and improve code generation, and will make it easier to determine how each callsite will behave before, during, and after alternative patching. It's not possible to load a module in the window between detecting the ARM64_WORKAROUND_843419 cpucap and patching alternatives. The module VA range limits are initialized much later in module_init_limits() which is a subsys_initcall, and module loading cannot happen before this. Hence it's not necessary for count_plts() or is_forbidden_offset_for_adrp() to use cpus_have_const_cap(). This patch replaces the use of cpus_have_const_cap() with cpus_have_final_cap() which will avoid generating code to test the system_cpucaps bitmap and should be better for all subsequent calls at runtime. Using cpus_have_final_cap() clearly documents that we do not expect this code to run before cpucaps are finalized, and will make it easier to spot issues if code is changed in future to allow modules to be loaded earlier. The ARM64_WORKAROUND_843419 cpucap is added to cpucap_is_possible() so that code can be elided entirely when this is not possible, and redundant IS_ENABLED() checks are removed. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
In count_plts() and is_forbidden_offset_for_adrp() we use
cpus_have_const_cap() to check for ARM64_WORKAROUND_843419, but this is
not necessary and cpus_have_final_cap() would be preferable.

For historical reasons, cpus_have_const_cap() is more complicated than
it needs to be. Before cpucaps are finalized, it will perform a bitmap
test of the system_cpucaps bitmap, and once cpucaps are finalized it
will use an alternative branch. This used to be necessary to handle some
race conditions in the window between cpucap detection and the
subsequent patching of alternatives and static branches, where different
branches could be out-of-sync with one another (or w.r.t. alternative
sequences). Now that we use alternative branches instead of static
branches, these are all patched atomically w.r.t. one another, and there
are only a handful of cases that need special care in the window between
cpucap detection and alternative patching.

Due to the above, it would be nice to remove cpus_have_const_cap(), and
migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(),
or cpus_have_cap() depending on when their requirements. This will
remove redundant instructions and improve code generation, and will make
it easier to determine how each callsite will behave before, during, and
after alternative patching.

It's not possible to load a module in the window between detecting the
ARM64_WORKAROUND_843419 cpucap and patching alternatives. The module VA
range limits are initialized much later in module_init_limits() which is
a subsys_initcall, and module loading cannot happen before this. Hence
it's not necessary for count_plts() or is_forbidden_offset_for_adrp() to
use cpus_have_const_cap().

This patch replaces the use of cpus_have_const_cap() with
cpus_have_final_cap() which will avoid generating code to test the
system_cpucaps bitmap and should be better for all subsequent calls at
runtime. Using cpus_have_final_cap() clearly documents that we do not
expect this code to run before cpucaps are finalized, and will make it
easier to spot issues if code is changed in future to allow modules to
be loaded earlier. The ARM64_WORKAROUND_843419 cpucap is added to
cpucap_is_possible() so that code can be elided entirely when this is not
possible, and redundant IS_ENABLED() checks are removed.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: module: Use module_init_layout_section() to spot init sections 2023-08-03T20:42:02+00:00 James Morse james.morse@arm.com 2023-08-01T14:54:08+00:00 f928f8b1a2496e7af95b860f9acf553f20f68f16 Today module_frob_arch_sections() spots init sections from their 'init' prefix, and uses this to keep the init PLTs separate from the rest. module_emit_plt_entry() uses within_module_init() to determine if a location is in the init text or not, but this depends on whether core code thought this was an init section. Naturally the logic is different. module_init_layout_section() groups the init and exit text together if module unloading is disabled, as the exit code will never run. The result is kernels with this configuration can't load all their modules because there are not enough PLTs for the combined init+exit section. This results in the following: | WARNING: CPU: 2 PID: 51 at arch/arm64/kernel/module-plts.c:99 module_emit_plt_entry+0x184/0x1cc | Modules linked in: crct10dif_common | CPU: 2 PID: 51 Comm: modprobe Not tainted 6.5.0-rc4-yocto-standard-dirty #15208 | Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 | pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : module_emit_plt_entry+0x184/0x1cc | lr : module_emit_plt_entry+0x94/0x1cc | sp : ffffffc0803bba60 [...] | Call trace: | module_emit_plt_entry+0x184/0x1cc | apply_relocate_add+0x2bc/0x8e4 | load_module+0xe34/0x1bd4 | init_module_from_file+0x84/0xc0 | __arm64_sys_finit_module+0x1b8/0x27c | invoke_syscall.constprop.0+0x5c/0x104 | do_el0_svc+0x58/0x160 | el0_svc+0x38/0x110 | el0t_64_sync_handler+0xc0/0xc4 | el0t_64_sync+0x190/0x194 A previous patch exposed module_init_layout_section(), use that so the logic is the same. Reported-by: Adam Johnston <adam.johnston@arm.com> Tested-by: Adam Johnston <adam.johnston@arm.com> Fixes: 055f23b74b20 ("module: check for exit sections in layout_sections() instead of module_init_section()") Cc: <stable@vger.kernel.org> # 5.15.x: 60a0aab7463ee69 arm64: module-plts: inline linux/moduleloader.h Cc: <stable@vger.kernel.org> # 5.15.x Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> 
Today module_frob_arch_sections() spots init sections from their
'init' prefix, and uses this to keep the init PLTs separate from the rest.

module_emit_plt_entry() uses within_module_init() to determine if a
location is in the init text or not, but this depends on whether
core code thought this was an init section.

Naturally the logic is different.

module_init_layout_section() groups the init and exit text together if
module unloading is disabled, as the exit code will never run. The result
is kernels with this configuration can't load all their modules because
there are not enough PLTs for the combined init+exit section.

This results in the following:
| WARNING: CPU: 2 PID: 51 at arch/arm64/kernel/module-plts.c:99 module_emit_plt_entry+0x184/0x1cc
| Modules linked in: crct10dif_common
| CPU: 2 PID: 51 Comm: modprobe Not tainted 6.5.0-rc4-yocto-standard-dirty #15208
| Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
| pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : module_emit_plt_entry+0x184/0x1cc
| lr : module_emit_plt_entry+0x94/0x1cc
| sp : ffffffc0803bba60
[...]
| Call trace:
|  module_emit_plt_entry+0x184/0x1cc
|  apply_relocate_add+0x2bc/0x8e4
|  load_module+0xe34/0x1bd4
|  init_module_from_file+0x84/0xc0
|  __arm64_sys_finit_module+0x1b8/0x27c
|  invoke_syscall.constprop.0+0x5c/0x104
|  do_el0_svc+0x58/0x160
|  el0_svc+0x38/0x110
|  el0t_64_sync_handler+0xc0/0xc4
|  el0t_64_sync+0x190/0x194

A previous patch exposed module_init_layout_section(), use that so the
logic is the same.

Reported-by: Adam Johnston <adam.johnston@arm.com>
Tested-by: Adam Johnston <adam.johnston@arm.com>
Fixes: 055f23b74b20 ("module: check for exit sections in layout_sections() instead of module_init_section()")
Cc: <stable@vger.kernel.org> # 5.15.x: 60a0aab7463ee69 arm64: module-plts: inline linux/moduleloader.h
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
arm64: module-plts: inline linux/moduleloader.h 2023-05-25T16:44:02+00:00 Arnd Bergmann arnd@arndb.de 2023-05-16T16:06:37+00:00 60a0aab7463ee69296692d980b96510ccce3934e module_frob_arch_sections() is declared in moduleloader.h, but that is not included before the definition: arch/arm64/kernel/module-plts.c:286:5: error: no previous prototype for 'module_frob_arch_sections' [-Werror=missing-prototypes] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20230516160642.523862-11-arnd@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
module_frob_arch_sections() is declared in moduleloader.h, but
that is not included before the definition:

arch/arm64/kernel/module-plts.c:286:5: error: no previous prototype for 'module_frob_arch_sections' [-Werror=missing-prototypes]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230516160642.523862-11-arnd@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
module: replace module_layout with module_memory 2023-03-09T20:55:15+00:00 Song Liu song@kernel.org 2023-02-07T00:28:02+00:00 ac3b43283923440900b4f36ca5f9f0b1ca43b70e module_layout manages different types of memory (text, data, rodata, etc.) in one allocation, which is problematic for some reasons: 1. It is hard to enable CONFIG_STRICT_MODULE_RWX. 2. It is hard to use huge pages in modules (and not break strict rwx). 3. Many archs uses module_layout for arch-specific data, but it is not obvious how these data are used (are they RO, RX, or RW?) Improve the scenario by replacing 2 (or 3) module_layout per module with up to 7 module_memory per module: MOD_TEXT, MOD_DATA, MOD_RODATA, MOD_RO_AFTER_INIT, MOD_INIT_TEXT, MOD_INIT_DATA, MOD_INIT_RODATA, and allocating them separately. This adds slightly more entries to mod_tree (from up to 3 entries per module, to up to 7 entries per module). However, this at most adds a small constant overhead to __module_address(), which is expected to be fast. Various archs use module_layout for different data. These data are put into different module_memory based on their location in module_layout. IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT; data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc. module_memory simplifies quite some of the module code. For example, ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a different allocator for the data. kernel/module/strict_rwx.c is also much cleaner with module_memory. Signed-off-by: Song Liu <song@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> 
module_layout manages different types of memory (text, data, rodata, etc.)
in one allocation, which is problematic for some reasons:

1. It is hard to enable CONFIG_STRICT_MODULE_RWX.
2. It is hard to use huge pages in modules (and not break strict rwx).
3. Many archs uses module_layout for arch-specific data, but it is not
   obvious how these data are used (are they RO, RX, or RW?)

Improve the scenario by replacing 2 (or 3) module_layout per module with
up to 7 module_memory per module:

        MOD_TEXT,
        MOD_DATA,
        MOD_RODATA,
        MOD_RO_AFTER_INIT,
        MOD_INIT_TEXT,
        MOD_INIT_DATA,
        MOD_INIT_RODATA,

and allocating them separately. This adds slightly more entries to
mod_tree (from up to 3 entries per module, to up to 7 entries per
module). However, this at most adds a small constant overhead to
__module_address(), which is expected to be fast.

Various archs use module_layout for different data. These data are put
into different module_memory based on their location in module_layout.
IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT;
data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc.

module_memory simplifies quite some of the module code. For example,
ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a
different allocator for the data. kernel/module/strict_rwx.c is also
much cleaner with module_memory.

Signed-off-by: Song Liu <song@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
arm64: module: Make plt_equals_entry() static 2022-09-29T16:47:18+00:00 Li Huafei lihuafei1@huawei.com 2022-09-29T09:41:32+00:00 3fb420f56cbf06b6ef8c39b886fed8f8f9aedee3 Since commit 4e69ecf4da1e ("arm64/module: ftrace: deal with place relative nature of PLTs"), plt_equals_entry() is not used outside of module-plts.c, so make it static. Signed-off-by: Li Huafei <lihuafei1@huawei.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20220929094134.99512-2-lihuafei1@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Since commit 4e69ecf4da1e ("arm64/module: ftrace: deal with place
relative nature of PLTs"), plt_equals_entry() is not used outside of
module-plts.c, so make it static.

Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220929094134.99512-2-lihuafei1@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: fix typos in comments 2022-04-04T09:32:50+00:00 Julia Lawall Julia.Lawall@inria.fr 2022-03-18T10:37:05+00:00 dd671f16b1cdb188aa64d740a408f7d00e281444 Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Link: https://lore.kernel.org/r/20220318103729.157574-10-Julia.Lawall@inria.fr [will: Squashed in 20220318103729.157574-28-Julia.Lawall@inria.fr] Signed-off-by: Will Deacon <will@kernel.org> 
Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20220318103729.157574-10-Julia.Lawall@inria.fr
[will: Squashed in 20220318103729.157574-28-Julia.Lawall@inria.fr]
Signed-off-by: Will Deacon <will@kernel.org>
arm64: improve whitespace 2021-02-04T13:59:49+00:00 Zhiyuan Dai daizhiyuan@phytium.com.cn 2021-02-04T01:43:49+00:00 d9f1b52afa4012974b3c726ca89ae311f194e83f In a few places we don't have whitespace between macro parameters, which makes them hard to read. This patch adds whitespace to clearly separate the parameters. In a few places we have unnecessary whitespace around unary operators, which is confusing, This patch removes the unnecessary whitespace. Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Link: https://lore.kernel.org/r/1612403029-5011-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Will Deacon <will@kernel.org> 
In a few places we don't have whitespace between macro parameters,
which makes them hard to read. This patch adds whitespace to clearly
separate the parameters.

In a few places we have unnecessary whitespace around unary operators,
which is confusing, This patch removes the unnecessary whitespace.

Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Link: https://lore.kernel.org/r/1612403029-5011-1-git-send-email-daizhiyuan@phytium.com.cn
Signed-off-by: Will Deacon <will@kernel.org>
arm64/module: set trampoline section flags regardless of CONFIG_DYNAMIC_FTRACE 2020-09-02T07:35:33+00:00 Jessica Yu jeyu@kernel.org 2020-09-01T16:00:16+00:00 e0328feda79d9681b3e3245e6e180295550c8ee9 In the arm64 module linker script, the section .text.ftrace_trampoline is specified unconditionally regardless of whether CONFIG_DYNAMIC_FTRACE is enabled (this is simply due to the limitation that module linker scripts are not preprocessed like the vmlinux one). Normally, for .plt and .text.ftrace_trampoline, the section flags present in the module binary wouldn't matter since module_frob_arch_sections() would assign them manually anyway. However, the arm64 module loader only sets the section flags for .text.ftrace_trampoline when CONFIG_DYNAMIC_FTRACE=y. That's only become problematic recently due to a recent change in binutils-2.35, where the .text.ftrace_trampoline section (along with the .plt section) is now marked writable and executable (WAX). We no longer allow writable and executable sections to be loaded due to commit 5c3a7db0c7ec ("module: Harden STRICT_MODULE_RWX"), so this is causing all modules linked with binutils-2.35 to be rejected under arm64. Drop the IS_ENABLED(CONFIG_DYNAMIC_FTRACE) check in module_frob_arch_sections() so that the section flags for .text.ftrace_trampoline get properly set to SHF_EXECINSTR|SHF_ALLOC, without SHF_WRITE. Signed-off-by: Jessica Yu <jeyu@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: http://lore.kernel.org/r/20200831094651.GA16385@linux-8ccs Link: https://lore.kernel.org/r/20200901160016.3646-1-jeyu@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
In the arm64 module linker script, the section .text.ftrace_trampoline
is specified unconditionally regardless of whether CONFIG_DYNAMIC_FTRACE
is enabled (this is simply due to the limitation that module linker
scripts are not preprocessed like the vmlinux one).

Normally, for .plt and .text.ftrace_trampoline, the section flags
present in the module binary wouldn't matter since module_frob_arch_sections()
would assign them manually anyway. However, the arm64 module loader only
sets the section flags for .text.ftrace_trampoline when CONFIG_DYNAMIC_FTRACE=y.
That's only become problematic recently due to a recent change in
binutils-2.35, where the .text.ftrace_trampoline section (along with the
.plt section) is now marked writable and executable (WAX).

We no longer allow writable and executable sections to be loaded due to
commit 5c3a7db0c7ec ("module: Harden STRICT_MODULE_RWX"), so this is
causing all modules linked with binutils-2.35 to be rejected under arm64.
Drop the IS_ENABLED(CONFIG_DYNAMIC_FTRACE) check in module_frob_arch_sections()
so that the section flags for .text.ftrace_trampoline get properly set to
SHF_EXECINSTR|SHF_ALLOC, without SHF_WRITE.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: http://lore.kernel.org/r/20200831094651.GA16385@linux-8ccs
Link: https://lore.kernel.org/r/20200901160016.3646-1-jeyu@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>