This is a note to let you know that I've just added the patch titled
ARM: 9292/1: vfp: Pass thread_info pointer to vfp_support_entry
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-9292-1-vfp-pass-thread_info-pointer-to-vfp_suppo.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d6e65078656a1b7b4b69fb93f36a27eb8226c4a1
Author: Ard Biesheuvel <ardb@xxxxxxxxxx>
Date: Tue Mar 21 12:01:02 2023 +0100
ARM: 9292/1: vfp: Pass thread_info pointer to vfp_support_entry
[ Upstream commit dae904d96ad6a5fa79bd9d99a3decf93685d398b ]
Instead of dereferencing thread_info in do_vfp, pass the thread_info
pointer to vfp_support_entry via R1. That way, we only use a single
caller save register, which makes it easier to convert do_vfp to C code
in a subsequent patch.
Note that, unlike the CPU number, which can change due to preemption,
passing the thread_info pointer can safely be done with preemption
enabled.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Stable-dep-of: c76c6c4ecbec ("ARM: 9294/2: vfp: Fix broken softirq handling with instrumentation enabled")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index 9a89264cdcc0b..cfedc2a3dbd68 100644
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -22,15 +22,12 @@
@ IRQs enabled.
@
ENTRY(do_vfp)
- local_bh_disable r10, r4
+ mov r1, r10
ldr r4, .LCvfp
- ldr r11, [r10, #TI_CPU] @ CPU number
- add r10, r10, #TI_VFPSTATE @ r10 = workspace
ldr pc, [r4] @ call VFP entry point
ENDPROC(do_vfp)
ENTRY(vfp_null_entry)
- local_bh_enable_ti r10, r4
ret lr
ENDPROC(vfp_null_entry)
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index 26c4f61ecfa39..6d056d810e486 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -6,9 +6,9 @@
* Written by Deep Blue Solutions Limited.
*
* This code is called from the kernel's undefined instruction trap.
+ * r1 holds the thread_info pointer
* r9 holds the return address for successful handling.
* lr holds the return address for unrecognised instructions.
- * r10 points at the start of the private FP workspace in the thread structure
* sp points to a struct pt_regs (as defined in include/asm/proc/ptrace.h)
*/
#include <linux/init.h>
@@ -69,13 +69,17 @@
@ VFP hardware support entry point.
@
@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
+@ r1 = thread_info pointer
@ r2 = PC value to resume execution after successful emulation
@ r9 = normal "successful" return address
-@ r10 = vfp_state union
-@ r11 = CPU number
@ lr = unrecognised instruction return address
@ IRQs enabled.
ENTRY(vfp_support_entry)
+ local_bh_disable r1, r4
+
+ ldr r11, [r1, #TI_CPU] @ CPU number
+ add r10, r1, #TI_VFPSTATE @ r10 = workspace
+
DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10
.fpu vfpv2
