From a0c02df519afdb921288df9e57efcd4a7fdb735a Mon Sep 17 00:00:00 2001 From: Cherry Mui Date: Fri, 4 Aug 2023 16:30:40 -0400 Subject: [PATCH] runtime/pprof: correct field alignment in machVMRegionBasicInfoData The type machVMRegionBasicInfoData is generated from C type vm_region_basic_info_data_64_t, which is a packed struct with a 64-bit field at offset 20. We cannot use uint64 as the field type in the Go struct, as that will be aligned at offset 24, which does not match the C struct. Change back to [8]byte (which is what the cgo command generates), but keep the name Offset. Updates #61707. Updates #50891. Change-Id: I2932328d7f9dfe9d79cff89752666c794d4d3788 Reviewed-on: https://go-review.googlesource.com/c/go/+/516156 Reviewed-by: Ian Lance Taylor TryBot-Result: Gopher Robot Run-TryBot: Cherry Mui --- src/runtime/pprof/defs_darwin_amd64.go | 2 +- src/runtime/pprof/defs_darwin_arm64.go | 2 +- src/runtime/pprof/vminfo_darwin.go | 7 ++++++- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/src/runtime/pprof/defs_darwin_amd64.go b/src/runtime/pprof/defs_darwin_amd64.go index 14226495d8..fa428b9386 100644 --- a/src/runtime/pprof/defs_darwin_amd64.go +++ b/src/runtime/pprof/defs_darwin_amd64.go @@ -9,7 +9,7 @@ type machVMRegionBasicInfoData struct { Inheritance uint32 Shared uint32 Reserved uint32 - Offset uint64 // This is hand-edited since godefs generates: Pad_cgo_0 [8]byte + Offset [8]byte // This is hand-edited since godefs generates: Pad_cgo_0 [8]byte. Cannot use uint64 due to alignment. Behavior int32 User_wired_count uint16 Pad_cgo_1 [2]byte diff --git a/src/runtime/pprof/defs_darwin_arm64.go b/src/runtime/pprof/defs_darwin_arm64.go index 2d34a80d80..16c68a2b73 100644 --- a/src/runtime/pprof/defs_darwin_arm64.go +++ b/src/runtime/pprof/defs_darwin_arm64.go @@ -9,7 +9,7 @@ type machVMRegionBasicInfoData struct { Inheritance uint32 Shared int32 Reserved int32 - Offset uint64 // This is hand-edited since godefs generates: Pad_cgo_0 [8]byte + Offset [8]byte // This is hand-edited since godefs generates: Pad_cgo_0 [8]byte. Cannot use uint64 due to alignment. Behavior int32 User_wired_count uint16 Pad_cgo_1 [2]byte diff --git a/src/runtime/pprof/vminfo_darwin.go b/src/runtime/pprof/vminfo_darwin.go index 7ddb0d1c68..35b9e6d487 100644 --- a/src/runtime/pprof/vminfo_darwin.go +++ b/src/runtime/pprof/vminfo_darwin.go @@ -39,7 +39,7 @@ func machVMInfo(addMapping func(lo, hi, offset uint64, file, buildID string)) bo // offset is usually 0. addMapping(addr, addr+memRegionSize, - uint64(info.Offset), + read64(&info.Offset), regionFilename(addr), "") added = true @@ -48,6 +48,11 @@ func machVMInfo(addMapping func(lo, hi, offset uint64, file, buildID string)) bo } } +func read64(p *[8]byte) uint64 { + // all supported darwin platforms are little endian + return uint64(p[0]) | uint64(p[1])<<8 | uint64(p[2])<<16 | uint64(p[3])<<24 | uint64(p[4])<<32 | uint64(p[5])<<40 | uint64(p[6])<<48 | uint64(p[7])<<56 +} + func regionFilename(address uint64) string { buf := make([]byte, _MAXPATHLEN) r := proc_regionfilename( -- 2.48.1