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| author | Ian Lance Taylor <ian@gcc.gnu.org> | 2019-02-27 22:35:10 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2019-02-27 22:35:10 +0000 |
| commit | cba8a572c208078c1c6eb9845b54f960526c53c0 (patch) | |
| tree | 2533982aacf337307ee72ee82ae77f3cb01fbd58 /libgo/go | |
| parent | e6df04c105464436e700013e1f665ebf0f94c9f2 (diff) | |
| download | gcc-cba8a572c208078c1c6eb9845b54f960526c53c0.zip gcc-cba8a572c208078c1c6eb9845b54f960526c53c0.tar.gz gcc-cba8a572c208078c1c6eb9845b54f960526c53c0.tar.bz2 | |
re PR go/89172 (FAIL: runtime/pprof)
PR go/89172
internal/cpu, runtime, runtime/pprof: handle function descriptors
When using PPC64 ELF ABI v1 a function address is not a PC, but is the
address of a function descriptor. The first field in the function
descriptor is the actual PC (see
http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#FUNC-DES).
The libbacktrace library knows about this, and libgo uses actual PC
values consistently except for the helper function funcPC that appears
in both runtime and runtime/pprof.
This patch fixes funcPC by recording, in the internal/cpu package,
whether function descriptors are being used. We have to check for
function descriptors using a C compiler check, because GCC can be
configured using --with-abi to select the ELF ABI to use.
Fixes https://gcc.gnu.org/PR89172
Reviewed-on: https://go-review.googlesource.com/c/162978
From-SVN: r269266
Diffstat (limited to 'libgo/go')
| -rw-r--r-- | libgo/go/runtime/pprof/proto.go | 10 | ||||
| -rw-r--r-- | libgo/go/runtime/proc.go | 9 |
2 files changed, 17 insertions, 2 deletions
diff --git a/libgo/go/runtime/pprof/proto.go b/libgo/go/runtime/pprof/proto.go index b82e738..27cd09e 100644 --- a/libgo/go/runtime/pprof/proto.go +++ b/libgo/go/runtime/pprof/proto.go @@ -8,6 +8,7 @@ import ( "bytes" "compress/gzip" "fmt" + internalcpu "internal/cpu" "io" "io/ioutil" "runtime" @@ -28,7 +29,14 @@ func funcPC(f interface{}) uintptr { data unsafe.Pointer } i := (*iface)(unsafe.Pointer(&f)) - return **(**uintptr)(i.data) + r := **(**uintptr)(i.data) + if internalcpu.FunctionDescriptors { + // With PPC64 ELF ABI v1 function descriptors the + // function address is a pointer to a struct whose + // first field is the actual PC. + r = *(*uintptr)(unsafe.Pointer(r)) + } + return r } // A profileBuilder writes a profile incrementally from a diff --git a/libgo/go/runtime/proc.go b/libgo/go/runtime/proc.go index 1c944d6..0e6c9e1 100644 --- a/libgo/go/runtime/proc.go +++ b/libgo/go/runtime/proc.go @@ -446,7 +446,14 @@ func releaseSudog(s *sudog) { //go:nosplit func funcPC(f interface{}) uintptr { i := (*iface)(unsafe.Pointer(&f)) - return **(**uintptr)(i.data) + r := **(**uintptr)(i.data) + if cpu.FunctionDescriptors { + // With PPC64 ELF ABI v1 function descriptors the + // function address is a pointer to a struct whose + // first field is the actual PC. + r = *(*uintptr)(unsafe.Pointer(r)) + } + return r } func lockedOSThread() bool { |