arm64: patching: avoid early page_to_phys()

When arm64 is configured with CONFIG_DEBUG_VIRTUAL=y, a warning is
printed from the patching code because patch_map(), e.g.

| ------------[ cut here ]---

arm64: patching: avoid early page_to_phys()

When arm64 is configured with CONFIG_DEBUG_VIRTUAL=y, a warning is
printed from the patching code because patch_map(), e.g.

| ------------[ cut here ]------------
| WARNING: CPU: 0 PID: 0 at arch/arm64/kernel/patching.c:45 patch_map.constprop.0+0x120/0xd00
| CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.13.0-rc1-00002-ge1a5d6c6be55 #1
| Hardware name: linux,dummy-virt (DT)
| pstate: 800003c5 (Nzcv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : patch_map.constprop.0+0x120/0xd00
| lr : patch_map.constprop.0+0x120/0xd00
| sp : ffffa9bb312a79a0
| x29: ffffa9bb312a79a0 x28: 0000000000000001 x27: 0000000000000001
| x26: 0000000000000000 x25: 0000000000000000 x24: 00000000000402e8
| x23: ffffa9bb2c94c1c8 x22: ffffa9bb2c94c000 x21: ffffa9bb222e883c
| x20: 0000000000000002 x19: ffffc1ffc100ba40 x18: ffffa9bb2cf0f21c
| x17: 0000000000000006 x16: 0000000000000000 x15: 0000000000000004
| x14: 1ffff5376625b4ac x13: ffff753766a67fb8 x12: ffff753766919cd1
| x11: 0000000000000003 x10: 1ffff5376625b4c3 x9 : 1ffff5376625b4af
| x8 : ffff753766254f0a x7 : 0000000041b58ab3 x6 : ffff753766254f18
| x5 : ffffa9bb312d9bc0 x4 : 0000000000000000 x3 : ffffa9bb29bd90e4
| x2 : 0000000000000002 x1 : ffffa9bb312d9bc0 x0 : 0000000000000000
| Call trace:
| patch_map.constprop.0+0x120/0xd00 (P)
| patch_map.constprop.0+0x120/0xd00 (L)
| __aarch64_insn_write+0xa8/0x120
| aarch64_insn_patch_text_nosync+0x4c/0xb8
| arch_jump_label_transform_queue+0x7c/0x100
| jump_label_update+0x154/0x460
| static_key_enable_cpuslocked+0x1d8/0x280
| static_key_enable+0x2c/0x48
| early_randomize_kstack_offset+0x104/0x168
| do_early_param+0xe4/0x148
| parse_args+0x3a4/0x838
| parse_early_options+0x50/0x68
| parse_early_param+0x58/0xe0
| setup_arch+0x78/0x1f0
| start_kernel+0xa0/0x530
| __primary_switched+0x8c/0xa0
| irq event stamp: 0
| hardirqs last enabled at (0): [<0000000000000000>] 0x0
| hardirqs last disabled at (0): [<0000000000000000>] 0x0
| softirqs last enabled at (0): [<0000000000000000>] 0x0
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| ---[ end trace 0000000000000000 ]---

The warning has been produced since commit:

3e25d5a49f99b75b ("asm-generic: add an optional pfn_valid check to page_to_phys")

... which added a pfn_valid() check into page_to_phys(), and at this
point in boot pfn_valid() will always return false because the vmemmap
has not yet been initialized and there are no valid mem_sections yet.

Before that commit, the arithmetic performed by page_to_phys() would
give the expected physical address, though it is somewhat dubious to use
vmemmap addresses before the vmemmap has been initialized.

Aside from kernel image addresses, all executable code should be
allocated from execmem (where all allocations will fall within the
vmalloc area), and so there's no need for the fallback case when
CONFIG_EXECMEM=n.

Simplify patch_map() accordingly, directly converting kernel image
addresses and removing the redundant fallback case.

Fixes: 3e25d5a49f99 ("asm-generic: add an optional pfn_valid check to page_to_phys")
Signed-off-by: Mark Rutland <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Thomas Huth <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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asm-generic: introduce text-patching.h

Several architectures support text patching, but they name the header
files that declare patching functions differently.

Make all such headers consistently na

asm-generic: introduce text-patching.h

Several architectures support text patching, but they name the header
files that declare patching functions differently.

Make all such headers consistently named text-patching.h and add an empty
header in asm-generic for architectures that do not support text patching.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]> # m68k
Acked-by: Arnd Bergmann <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Tested-by: kdevops <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Brian Cain <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: John Paul Adrian Glaubitz <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masami Hiramatsu (Google) <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Russell King <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Stafford Horne <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Uladzislau Rezki (Sony) <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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arm64: patching: fix handling of execmem addresses

Klara Modin reported warnings for a kernel configured with BPF_JIT but
without MODULES:

[ 44.131296] Trying to vfree() bad address (000000004a17

arm64: patching: fix handling of execmem addresses

Klara Modin reported warnings for a kernel configured with BPF_JIT but
without MODULES:

[ 44.131296] Trying to vfree() bad address (000000004a17c299)
[ 44.138024] WARNING: CPU: 1 PID: 193 at mm/vmalloc.c:3189 remove_vm_area (mm/vmalloc.c:3189 (discriminator 1))
[ 44.146675] CPU: 1 PID: 193 Comm: kworker/1:2 Tainted: G D W 6.9.0-01786-g2c9e5d4a0082 #25
[ 44.158229] Hardware name: Raspberry Pi 3 Model B (DT)
[ 44.164433] Workqueue: events bpf_prog_free_deferred
[ 44.170492] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 44.178601] pc : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1))
[ 44.183705] lr : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1))
[ 44.188772] sp : ffff800082a13c70
[ 44.193112] x29: ffff800082a13c70 x28: 0000000000000000 x27: 0000000000000000
[ 44.201384] x26: 0000000000000000 x25: ffff00003a44efa0 x24: 00000000d4202000
[ 44.209658] x23: ffff800081223dd0 x22: ffff00003a198a40 x21: ffff8000814dd880
[ 44.217924] x20: 00000000d4202000 x19: ffff8000814dd880 x18: 0000000000000006
[ 44.226206] x17: 0000000000000000 x16: 0000000000000020 x15: 0000000000000002
[ 44.234460] x14: ffff8000811a6370 x13: 0000000020000000 x12: 0000000000000000
[ 44.242710] x11: ffff8000811a6370 x10: 0000000000000144 x9 : ffff8000811fe370
[ 44.250959] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000811fe370
[ 44.259206] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[ 44.267457] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000002203240
[ 44.275703] Call trace:
[ 44.279158] remove_vm_area (mm/vmalloc.c:3189 (discriminator 1))
[ 44.283858] vfree (mm/vmalloc.c:3322)
[ 44.287835] execmem_free (mm/execmem.c:70)
[ 44.292347] bpf_jit_free_exec+0x10/0x1c
[ 44.297283] bpf_prog_pack_free (kernel/bpf/core.c:1006)
[ 44.302457] bpf_jit_binary_pack_free (kernel/bpf/core.c:1195)
[ 44.307951] bpf_jit_free (include/linux/filter.h:1083 arch/arm64/net/bpf_jit_comp.c:2474)
[ 44.312342] bpf_prog_free_deferred (kernel/bpf/core.c:2785)
[ 44.317785] process_one_work (kernel/workqueue.c:3273)
[ 44.322684] worker_thread (kernel/workqueue.c:3342 (discriminator 2) kernel/workqueue.c:3429 (discriminator 2))
[ 44.327292] kthread (kernel/kthread.c:388)
[ 44.331342] ret_from_fork (arch/arm64/kernel/entry.S:861)

The problem is because bpf_arch_text_copy() silently fails to write to the
read-only area as a result of patch_map() faulting and the resulting
-EFAULT being chucked away.

Update patch_map() to use CONFIG_EXECMEM instead of
CONFIG_STRICT_MODULE_RWX to check for vmalloc addresses.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 2c9e5d4a0082 ("bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of")
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Reported-by: Klara Modin <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]
Tested-by: Klara Modin <[email protected]>
Cc: Björn Töpel <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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arm64: patching: implement text_poke API

The text_poke API is used to implement functions like memcpy() and
memset() for instruction memory (RO+X). The implementation is similar to
the x86 version.

arm64: patching: implement text_poke API

The text_poke API is used to implement functions like memcpy() and
memset() for instruction memory (RO+X). The implementation is similar to
the x86 version.

This will be used by the BPF JIT to write and modify BPF programs. There
could be more users of this in the future.

Signed-off-by: Puranjay Mohan <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

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arm64: patching: Add aarch64_insn_write_literal_u64()

In subsequent patches we'll need to atomically write to a
naturally-aligned 64-bit literal embedded within the kernel text.

Add a helper for th

arm64: patching: Add aarch64_insn_write_literal_u64()

In subsequent patches we'll need to atomically write to a
naturally-aligned 64-bit literal embedded within the kernel text.

Add a helper for this. For consistency with other text patching code we
use copy_to_kernel_nofault(), which is atomic for naturally-aligned
accesses up to 64-bits.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Florent Revest <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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arm64: patch_text: Fixup last cpu should be master

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU pat

arm64: patch_text: Fixup last cpu should be master

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Fixes: ae16480785de ("arm64: introduce interfaces to hotpatch kernel and module code")
Signed-off-by: Guo Ren <[email protected]>
Signed-off-by: Guo Ren <[email protected]>
Reviewed-by: Catalin Marinas <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

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arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>

For histroical reasons, we define AARCH64_INSN_SIZE in
<asm/alternative-macros.h>, but it would make more sense to do so in
<asm/insn.h>. Let's

arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>

For histroical reasons, we define AARCH64_INSN_SIZE in
<asm/alternative-macros.h>, but it would make more sense to do so in
<asm/insn.h>. Let's move it into <asm/insn.h>, and add the necessary
include directives for this.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

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arm64: insn: decouple patching from insn code

Currently, <asm/insn.h> includes <asm/patching.h>. We intend that
<asm/insn.h> will be usable from userspace, so it doesn't make sense to
include header

arm64: insn: decouple patching from insn code

Currently, <asm/insn.h> includes <asm/patching.h>. We intend that
<asm/insn.h> will be usable from userspace, so it doesn't make sense to
include headers for kernel-only features such as the patching routines,
and we'd intended to restrict <asm/insn.h> to instruction encoding
details.

Let's decouple the patching code from <asm/insn.h>, and explicitly
include <asm/patching.h> where it is needed. Since <asm/patching.h>
isn't included from assembly, we can drop the __ASSEMBLY__ guards.

At the same time, sort the kprobes includes so that it's easier to see
what is and isn't incldued.

Signed-off-by: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

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arm64: Move patching utilities out of instruction encoding/decoding

Files insn.[c|h] containt some functions used for instruction patching.
In order to reuse the instruction encoder/decoder, move th

arm64: Move patching utilities out of instruction encoding/decoding

Files insn.[c|h] containt some functions used for instruction patching.
In order to reuse the instruction encoder/decoder, move the patching
utilities to their own file.

Signed-off-by: Julien Thierry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[will: Include patching.h in insn.h to fix header mess; add __ASSEMBLY__ guards]
Signed-off-by: Will Deacon <[email protected]>

Signed-off-by: Will Deacon <[email protected]>

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