linux-stable.git/arch/powerpc/kernel/entry_32.S, branch v6.2 Linux kernel stable tree Merge branch 'topic/objtool' into next 2022-12-08T12:57:47+00:00 Michael Ellerman mpe@ellerman.id.au 2022-12-08T12:57:47+00:00 f24f21c4122e837fa031cc512a7f20eb8c554c5e Merge the powerpc objtool support, which we were keeping in a topic branch in case of any merge conflicts. 
Merge the powerpc objtool support, which we were keeping in a topic
branch in case of any merge conflicts.
powerpc: add a define for the switch frame size and regs offset 2022-12-02T06:54:08+00:00 Nicholas Piggin npiggin@gmail.com 2022-11-27T12:49:36+00:00 6f291a03819e4051ebc870471d26915ef2e6ba31 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 
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
powerpc: add a definition for the marker offset within the interrupt frame 2022-12-02T06:54:08+00:00 Nicholas Piggin npiggin@gmail.com 2022-11-27T12:49:33+00:00 d2e8ff9f1492f44c5a6d93f759eea27574d753de 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 
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
powerpc: add definition for pt_regs offset within an interrupt frame 2022-12-02T06:54:08+00:00 Nicholas Piggin npiggin@gmail.com 2022-11-27T12:49:32+00:00 c03be0a3f3cc656eab5c427b78959b8f1b169a11 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 
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
powerpc/32: Fix objtool unannotated intra-function call warnings 2022-11-18T08:00:06+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2022-11-14T17:57:44+00:00 2da37761671b5bdedbe04e6469cfa57cd6b6ae45 Fix several annotations in assembly files on PPC32. [Sathvika Vasireddy: Changed subject line and removed Kconfig change to enable objtool, as it is a part of "objtool/powerpc: Enable objtool to be built on ppc" patch in this series.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-7-sv@linux.ibm.com 
Fix several annotations in assembly files on PPC32.

[Sathvika Vasireddy: Changed subject line and removed Kconfig change to
 enable objtool, as it is a part of "objtool/powerpc: Enable objtool to
 be built on ppc" patch in this series.]

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-7-sv@linux.ibm.com
powerpc/64: use 32-bit immediate for STACK_FRAME_REGS_MARKER 2022-09-28T09:22:12+00:00 Nicholas Piggin npiggin@gmail.com 2022-09-26T03:40:53+00:00 17773afdcd1589c5925a984f512330410cb2ba4f 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 
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
powerpc: Change system_call_exception calling convention 2022-09-28T09:22:09+00:00 Rohan McLure rmclure@linux.ibm.com 2022-09-21T06:56:00+00:00 f8971c627b14040e533768985a99f4fd6ffa420f Change system_call_exception arguments to pass a pointer to a stack frame container caller state, as well as the original r0, which determines the number of the syscall. This has been observed to yield improved performance to passing them by registers, circumventing the need to allocate a stack frame. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Retain clearing of high bits of args for compat tasks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-21-rmclure@linux.ibm.com 
Change system_call_exception arguments to pass a pointer to a stack
frame container caller state, as well as the original r0, which
determines the number of the syscall. This has been observed to yield
improved performance to passing them by registers, circumventing the
need to allocate a stack frame.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain clearing of high bits of args for compat tasks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-21-rmclure@linux.ibm.com
powerpc/32: Clarify interrupt restores with REST_GPR macro in entry_32.S 2022-09-26T13:00:15+00:00 Rohan McLure rmclure@linux.ibm.com 2022-09-21T06:55:45+00:00 15ba74502ccfd0b34dad0ea022093ccc66b334d6 Restoring the register state of the interrupted thread involves issuing a large number of predictable loads to the kernel stack frame. Issue the REST_GPR{,S} macros to clearly signal when this is happening, and bunch together restores at the end of the interrupt handler where the saved value is not consumed earlier in the handler code. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-6-rmclure@linux.ibm.com 
Restoring the register state of the interrupted thread involves issuing
a large number of predictable loads to the kernel stack frame. Issue the
REST_GPR{,S} macros to clearly signal when this is happening, and bunch
together restores at the end of the interrupt handler where the saved
value is not consumed earlier in the handler code.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-6-rmclure@linux.ibm.com
powerpc: Save caller r3 prior to system_call_exception 2022-09-26T13:00:14+00:00 Rohan McLure rmclure@linux.ibm.com 2022-09-21T06:55:42+00:00 2c27d4a419f627636b8c6038e55acb26df05c391 This reverts commit 8875f47b7681 ("powerpc/syscall: Save r3 in regs->orig_r3 "). Save caller's original r3 state to the kernel stackframe before entering system_call_exception. This allows for user registers to be cleared by the time system_call_exception is entered, reducing the influence of user registers on speculation within the kernel. Prior to this commit, orig_r3 was saved at the beginning of system_call_exception. Instead, save orig_r3 while the user value is still live in r3. Also replicate this early save in 32-bit. A similar save was removed in commit 6f76a01173cc ("powerpc/syscall: implement system call entry/exit logic in C for PPC32") when 32-bit adopted system_call_exception. Revert its removal of orig_r3 saves. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220921065605.1051927-3-rmclure@linux.ibm.com 
This reverts commit 8875f47b7681 ("powerpc/syscall: Save r3 in regs->orig_r3
").

Save caller's original r3 state to the kernel stackframe before entering
system_call_exception. This allows for user registers to be cleared by
the time system_call_exception is entered, reducing the influence of
user registers on speculation within the kernel.

Prior to this commit, orig_r3 was saved at the beginning of
system_call_exception. Instead, save orig_r3 while the user value is
still live in r3.

Also replicate this early save in 32-bit. A similar save was removed in
commit 6f76a01173cc ("powerpc/syscall: implement system call entry/exit
logic in C for PPC32") when 32-bit adopted system_call_exception. Revert
its removal of orig_r3 saves.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-3-rmclure@linux.ibm.com
powerpc: Remove CONFIG_PPC_BOOK3E_MMU 2022-09-26T13:00:14+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2022-09-19T17:01:39+00:00 aa5f59df201dd350f7c291c845ac8b62c0d0edd5 CONFIG_PPC_BOOK3E_MMU is redundant with CONFIG_PPC_E500. Remove it. Also rename mmu-book3e.h to mmu-e500.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/c5549cd59a131204ff94ab909cad2e2dad4ddf2f.1663606876.git.christophe.leroy@csgroup.eu 
CONFIG_PPC_BOOK3E_MMU is redundant with CONFIG_PPC_E500.

Remove it.

Also rename mmu-book3e.h to mmu-e500.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/c5549cd59a131204ff94ab909cad2e2dad4ddf2f.1663606876.git.christophe.leroy@csgroup.eu