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author | Austin Clements <austin@google.com> | 2014-10-27 17:12:48 -0400 |
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committer | Austin Clements <austin@google.com> | 2014-10-27 17:12:48 -0400 |
commit | e7797eae182f602d8d08d936f74257a93484d5fd (patch) | |
tree | f107f84fe39f9d479e7b2345fa405490e655c3f5 | |
parent | 71b84afc8f2118f7d8d5ed4293a7e35f4b1cb511 (diff) | |
download | go-e7797eae182f602d8d08d936f74257a93484d5fd.tar.gz |
runtime: fix endianness assumption when decoding ftab
The ftab ends with a half functab record consisting only of
the 'entry' field followed by a uint32 giving the offset of
the next table. Previously, symtabinit assumed it could read
this uint32 as a uintptr. Since this is unsafe on big endian,
explicitly read the offset as a uint32.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/157660043
-rw-r--r-- | src/runtime/symtab.go | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go index 48d4023b9..45d107b77 100644 --- a/src/runtime/symtab.go +++ b/src/runtime/symtab.go @@ -84,10 +84,13 @@ func symtabinit() { } } - // file table follows ftab. + // The ftab ends with a half functab consisting only of + // 'entry', followed by a uint32 giving the pcln-relative + // offset of the file table. sp = (*sliceStruct)(unsafe.Pointer(&filetab)) - p = unsafe.Pointer(add(unsafe.Pointer(pcln), ftab[nftab].funcoff)) - sp.array = unsafe.Pointer(add(unsafe.Pointer(pcln), ftab[nftab].funcoff)) + end := unsafe.Pointer(&ftab[nftab].funcoff) // just beyond ftab + fileoffset := *(*uint32)(end) + sp.array = unsafe.Pointer(&pclntable[fileoffset]) // length is in first element of array. // set len to 1 so we can get first element. sp.len = 1 @@ -224,7 +227,7 @@ func funcline(f *_func, targetpc uintptr, file *string) int32 { func funcspdelta(f *_func, targetpc uintptr) int32 { x := pcvalue(f, f.pcsp, targetpc, true) if x&(ptrSize-1) != 0 { - print("invalid spdelta ", f.pcsp, " ", x, "\n") + print("invalid spdelta ", hex(f.entry), " ", hex(targetpc), " ", hex(f.pcsp), " ", x, "\n") } return x } |