2020-05-09 17:07:11

by Christophe Leroy

Subject: [PATCH fixes] powerpc/40x: Make more space for system call exception

When CONFIG_VIRT_CPU_ACCOUNTING is selected, system call exception
handler doesn't fit below 0xd00 and build fails.

As exception 0xd00 doesn't exist and is never generated by 40x,
comment it out in order to get more space for system call exception.

Reported-by: kbuild test robot <[email protected]>
Fixes: 9e27086292aa ("powerpc/32: Warn and return ENOSYS on syscalls from kernel")
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/head_40x.S | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 9bb663977e84..2cec543c38f0 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -344,8 +344,9 @@ _ENTRY(saved_ksp_limit)
/* 0x0C00 - System Call Exception */
START_EXCEPTION(0x0C00, SystemCall)
SYSCALL_ENTRY 0xc00
+/* Trap_0D is commented out to get more space for system call exception */

- EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD)
+/* EXCEPTION(0x0D00, Trap_0D, unknown_exception, EXC_XFER_STD) */
EXCEPTION(0x0E00, Trap_0E, unknown_exception, EXC_XFER_STD)
EXCEPTION(0x0F00, Trap_0F, unknown_exception, EXC_XFER_STD)

--
2.25.0

2020-05-13 20:42:33

by Michael Ellerman

Subject: Re: [PATCH fixes] powerpc/40x: Make more space for system call exception

On Sat, 9 May 2020 17:05:11 +0000 (UTC), Christophe Leroy wrote:
> When CONFIG_VIRT_CPU_ACCOUNTING is selected, system call exception
> handler doesn't fit below 0xd00 and build fails.
>
> As exception 0xd00 doesn't exist and is never generated by 40x,
> comment it out in order to get more space for system call exception.

Applied to powerpc/fixes.

[1/1] powerpc/40x: Make more space for system call exception
https://git.kernel.org/powerpc/c/249c9b0cd193d983c3a0b00f3fd3b92333bfeebe

cheers