kernel/linux.git/arch/powerpc/include/asm/kup.h, branch linux-7.0.y

powerpc/uaccess: Remove {allow/prevent}_{read/write/read_write}_{from/to/}_user()

2026-01-07T04:01:04+00:00

The six following functions have become simple single-line fonctions that do not have much added value anymore: - allow_read_from_user() - allow_write_to_user() - allow_read_write_user() - prevent_read_from_user() - prevent_write_to_user() - prevent_read_write_user() Directly call allow_user_access() and prevent_user_access(), it doesn't reduce the readability and it removes unnecessary middle functions. Signed-off-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/70971f0ba81eab742a120e5bfdeff6b42d08fd98.1766574657.git.chleroy@kernel.org

powerpc/uaccess: Remove unused size and from parameters from allow_access_user()

2026-01-07T04:01:04+00:00

Since commit 16132529cee5 ("powerpc/32s: Rework Kernel Userspace Access Protection") the size parameter is unused on all platforms. And the 'from' parameter has never been used. Remove them. Signed-off-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/4552b00707923b71150ee47b925d6eaae1b03261.1766574657.git.chleroy@kernel.org

powerpc/uaccess: Move barrier_nospec() out of allow_read_{from/write}_user()

2026-01-07T04:01:04+00:00

Commit 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") added a redundant barrier_nospec() in copy_from_user(), because powerpc is already calling barrier_nospec() in allow_read_from_user() and allow_read_write_user(). But on other architectures that call to barrier_nospec() was missing. So change powerpc instead of reverting the above commit and having to fix other architectures one by one. This is now possible because barrier_nospec() has also been added in copy_from_user_iter(). Move barrier_nospec() out of allow_read_from_user() and allow_read_write_user(). This will also allow reuse of those functions when implementing masked user access which doesn't require barrier_nospec(). Don't add it back in raw_copy_from_user() as it is already called by copy_from_user() and copy_from_user_iter(). Fixes: 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") Signed-off-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/f29612105c5fcbc8ceb7303808ddc1a781f0f6b5.1766574657.git.chleroy@kernel.org

powerpc: Replace ASSEMBLY with ASSEMBLER in non-uapi headers

2025-09-01T07:53:29+00:00

While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembler code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This is bad since macros starting with two underscores are names that are reserved by the C language. It can also be very confusing for the developers when switching between userspace and kernelspace coding, or when dealing with uapi headers that rather should use __ASSEMBLER__ instead. So let's standardize now on the __ASSEMBLER__ macro that is provided by the compilers. This is almost a completely mechanical patch (done with a simple "sed -i" statement), apart from tweaking two comments manually in arch/powerpc/include/asm/bug.h and arch/powerpc/include/asm/kasan.h (which did not have proper underscores at the end) and fixing a checkpatch error about spaces in arch/powerpc/include/asm/spu_csa.h. Signed-off-by: Thomas Huth Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250801082007.32904-3-thuth@redhat.com

powerpc/4xx: Remove CONFIG_BOOKE_OR_40x

2024-06-28T12:28:48+00:00

Now that 40x is gone, replace CONFIG_BOOKE_OR_40x by CONFIG_BOOKE. Signed-off-by: Michael Ellerman Link: https://msgid.link/20240628121201.130802-5-mpe@ellerman.id.au

powerpc/kuap: Use ASM feature fixups instead of static branches

2023-08-02T12:22:18+00:00

To avoid a useless nop on top of every uaccess enable/disable and make life easier for objtool, replace static branches by ASM feature fixups that will nop KUAP enabling instructions out in the unlikely case KUAP is disabled at boottime. Leave it as is on book3s/64 for now, it will be handled later when objtool is activated on PPC64. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/671948788024fd890ec4ed175bc332dab8664ea5.1689091022.git.christophe.leroy@csgroup.eu

powerpc/kuap: KUAP enabling/disabling functions must be __always_inline

2023-08-02T12:22:18+00:00

Objtool reports following warnings: arch/powerpc/kernel/signal_32.o: warning: objtool: __prevent_user_access.constprop.0+0x4 (.text+0x4): redundant UACCESS disable arch/powerpc/kernel/signal_32.o: warning: objtool: user_access_begin+0x2c (.text+0x4c): return with UACCESS enabled arch/powerpc/kernel/signal_32.o: warning: objtool: handle_rt_signal32+0x188 (.text+0x360): call to __prevent_user_access.constprop.0() with UACCESS enabled arch/powerpc/kernel/signal_32.o: warning: objtool: handle_signal32+0x150 (.text+0x4d4): call to __prevent_user_access.constprop.0() with UACCESS enabled This is due to some KUAP enabling/disabling functions being outline allthough they are marked inline. Use __always_inline instead. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/ca5e50ddbec3867db5146ebddbc9a1dc0e443bc8.1689091022.git.christophe.leroy@csgroup.eu

powerpc/kuap: Use MMU_FTR_KUAP on all and refactor disabling kuap

2023-08-02T12:22:18+00:00

All but book3s/64 use a static branch key for disabling kuap. book3s/64 uses an mmu feature. Refactor all targets to use MMU_FTR_KUAP like book3s/64. For PPC32 that implies updating mmu features fixups once KUAP has been initialised. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/6b3d7c977bad73378ea368bc6818e9c94ea95ab0.1689091022.git.christophe.leroy@csgroup.eu

powerpc/kuap: Avoid useless jump_label on empty function

2023-08-02T12:22:17+00:00

Disassembly of interrupt_enter_prepare() shows a pointless nop before the mftb c000abf0 : c000abf0: 81 23 00 84 lwz r9,132(r3) c000abf4: 71 29 40 00 andi. r9,r9,16384 c000abf8: 41 82 00 28 beq- c000ac20 c000abfc: ===> 60 00 00 00 nop <==== c000ac00: 7d 0c 42 e6 mftb r8 c000ac04: 80 e2 00 08 lwz r7,8(r2) c000ac08: 81 22 00 28 lwz r9,40(r2) c000ac0c: 91 02 00 24 stw r8,36(r2) c000ac10: 7d 29 38 50 subf r9,r9,r7 c000ac14: 7d 29 42 14 add r9,r9,r8 c000ac18: 91 22 00 08 stw r9,8(r2) c000ac1c: 4e 80 00 20 blr c000ac20: 60 00 00 00 nop c000ac24: 7d 5a c2 a6 mfmd_ap r10 c000ac28: 3d 20 de 00 lis r9,-8704 c000ac2c: 91 43 00 b0 stw r10,176(r3) c000ac30: 7d 3a c3 a6 mtspr 794,r9 c000ac34: 4e 80 00 20 blr That comes from the call to kuap_loc(), allthough __kuap_lock() is an empty function on the 8xx. To avoid that, only perform kuap_is_disabled() check when there is something to do with __kuap_lock(). Do the same with __kuap_save_and_lock() and __kuap_get_and_assert_locked(). Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/a854d25bea375d4ba6ca9c2617f9edbba397100a.1689091022.git.christophe.leroy@csgroup.eu

powerpc/kuap: Remove unused inline function __kuap_assert_locked()

2022-05-04T09:37:46+00:00

commit 2341964e27b0 ("powerpc/kuap: Remove __kuap_assert_locked()") left behind this one, remove it. Signed-off-by: YueHaibing Acked-by: Christophe Leroy Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220311130017.22936-1-yuehaibing@huawei.com

kernel/linux.git/arch/powerpc/include/asm/kup.h, branch linux-7.0.y

powerpc/uaccess: Remove {allow/prevent}_{read/write/read_write}_{from/to/}_user()

powerpc/uaccess: Remove unused size and from parameters from allow_access_user()

powerpc/uaccess: Move barrier_nospec() out of allow_read_{from/write}_user()

powerpc: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers

powerpc/4xx: Remove CONFIG_BOOKE_OR_40x

powerpc/kuap: Use ASM feature fixups instead of static branches

powerpc/kuap: KUAP enabling/disabling functions must be __always_inline

powerpc/kuap: Use MMU_FTR_KUAP on all and refactor disabling kuap

powerpc/kuap: Avoid useless jump_label on empty function

powerpc/kuap: Remove unused inline function __kuap_assert_locked()

powerpc: Replace ASSEMBLY with ASSEMBLER in non-uapi headers