runtime,runtime/cgo: save callee-saved FP register on arm
Other GOARCHs already handle their callee-saved FP registers, but
arm was missing. Without this change, code using Cgo and floating
point code might fail in mysterious and hard to debug ways.
There are no floating point registers when GOARM=5, so skip the
registers when runtime.goarm < 6.
darwin/arm doesn't support GOARM=5, so the check is left out of
rt0_darwin_arm.s.
Fixes #14876
Change-Id: I6bcb90a76df3664d8ba1f33123a74b1eb2c9f8b2
Reviewed-on: https://go-review.googlesource.com/23140
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
diff --git a/src/runtime/cgo/asm_arm.s b/src/runtime/cgo/asm_arm.s
index 08472b6..0f35422 100644
--- a/src/runtime/cgo/asm_arm.s
+++ b/src/runtime/cgo/asm_arm.s
@@ -16,8 +16,40 @@
* Additionally, runtime·load_g will clobber R0, so we need to save R0
* nevertheless.
*/
+ SUB $(8*9), R13 // Reserve space for the floating point registers.
MOVM.WP [R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, g, R11, R12, R14], (R13)
+
+ // Skip floating point registers on GOARM < 6.
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfpsave
+ MOVD F8, (14*4+8*1)(R13)
+ MOVD F9, (14*4+8*2)(R13)
+ MOVD F10, (14*4+8*3)(R13)
+ MOVD F11, (14*4+8*4)(R13)
+ MOVD F12, (14*4+8*5)(R13)
+ MOVD F13, (14*4+8*6)(R13)
+ MOVD F14, (14*4+8*7)(R13)
+ MOVD F15, (14*4+8*8)(R13)
+
+skipfpsave:
BL runtime·load_g(SB)
MOVW R15, R14 // R15 is PC.
MOVW 0(R13), R15
- MOVM.IAW (R13), [R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, g, R11, R12, R15]
+
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfprest
+ MOVD (14*4+8*1)(R13), F8
+ MOVD (14*4+8*2)(R13), F9
+ MOVD (14*4+8*3)(R13), F10
+ MOVD (14*4+8*4)(R13), F11
+ MOVD (14*4+8*5)(R13), F12
+ MOVD (14*4+8*6)(R13), F13
+ MOVD (14*4+8*7)(R13), F14
+ MOVD (14*4+8*8)(R13), F15
+
+skipfprest:
+ MOVM.IAW (R13), [R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, g, R11, R12, R14]
+ ADD $(8*9), R13
+ MOVW R14, R15
diff --git a/src/runtime/rt0_darwin_arm.s b/src/runtime/rt0_darwin_arm.s
index 59733d3..526d88f 100644
--- a/src/runtime/rt0_darwin_arm.s
+++ b/src/runtime/rt0_darwin_arm.s
@@ -16,7 +16,7 @@
//
// Note that all currently shipping darwin/arm platforms require
// cgo and do not support c-shared.
-TEXT _rt0_arm_darwin_lib(SB),NOSPLIT,$32
+TEXT _rt0_arm_darwin_lib(SB),NOSPLIT,$104
// Preserve callee-save registers.
MOVW R4, 12(R13)
MOVW R5, 16(R13)
@@ -25,6 +25,15 @@
MOVW R8, 28(R13)
MOVW R11, 32(R13)
+ MOVD F8, (32+8*1)(R13)
+ MOVD F9, (32+8*2)(R13)
+ MOVD F10, (32+8*3)(R13)
+ MOVD F11, (32+8*4)(R13)
+ MOVD F12, (32+8*5)(R13)
+ MOVD F13, (32+8*6)(R13)
+ MOVD F14, (32+8*7)(R13)
+ MOVD F15, (32+8*8)(R13)
+
MOVW R0, _rt0_arm_darwin_lib_argc<>(SB)
MOVW R1, _rt0_arm_darwin_lib_argv<>(SB)
@@ -57,6 +66,14 @@
MOVW 24(R13), R7
MOVW 28(R13), R8
MOVW 32(R13), R11
+ MOVD (32+8*1)(R13), F8
+ MOVD (32+8*2)(R13), F9
+ MOVD (32+8*3)(R13), F10
+ MOVD (32+8*4)(R13), F11
+ MOVD (32+8*5)(R13), F12
+ MOVD (32+8*6)(R13), F13
+ MOVD (32+8*7)(R13), F14
+ MOVD (32+8*8)(R13), F15
RET
diff --git a/src/runtime/rt0_linux_arm.s b/src/runtime/rt0_linux_arm.s
index a4419b8..597e642 100644
--- a/src/runtime/rt0_linux_arm.s
+++ b/src/runtime/rt0_linux_arm.s
@@ -12,7 +12,7 @@
// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
-TEXT _rt0_arm_linux_lib(SB),NOSPLIT,$32
+TEXT _rt0_arm_linux_lib(SB),NOSPLIT,$104
// Preserve callee-save registers. Raspberry Pi's dlopen(), for example,
// actually cares that R11 is preserved.
MOVW R4, 12(R13)
@@ -22,6 +22,19 @@
MOVW R8, 28(R13)
MOVW R11, 32(R13)
+ // Skip floating point registers on GOARM < 6.
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfpsave
+ MOVD F8, (32+8*1)(R13)
+ MOVD F9, (32+8*2)(R13)
+ MOVD F10, (32+8*3)(R13)
+ MOVD F11, (32+8*4)(R13)
+ MOVD F12, (32+8*5)(R13)
+ MOVD F13, (32+8*6)(R13)
+ MOVD F14, (32+8*7)(R13)
+ MOVD F15, (32+8*8)(R13)
+skipfpsave:
// Save argc/argv.
MOVW R0, _rt0_arm_linux_lib_argc<>(SB)
MOVW R1, _rt0_arm_linux_lib_argv<>(SB)
@@ -46,6 +59,18 @@
BL runtime·newosproc0(SB)
rr:
// Restore callee-save registers and return.
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfprest
+ MOVD (32+8*1)(R13), F8
+ MOVD (32+8*2)(R13), F9
+ MOVD (32+8*3)(R13), F10
+ MOVD (32+8*4)(R13), F11
+ MOVD (32+8*5)(R13), F12
+ MOVD (32+8*6)(R13), F13
+ MOVD (32+8*7)(R13), F14
+ MOVD (32+8*8)(R13), F15
+skipfprest:
MOVW 12(R13), R4
MOVW 16(R13), R5
MOVW 20(R13), R6
