cmd/link: try libssp_nonshared.a when looking for "__stack_chk_fail_local"

Update the code that tries to satisfy unresolved references to
"__stack_chk_fail_local" to look for "libssp_nonshared.a" in addition
to "libc_nonshared.a" (the former archive is the correct place on
Alpine).

Updates golang#52919.
Updates golang#54313.
Updates golang#57261.
Fixes golang#58385.

Change-Id: Id6cd3ebb4d5388df50a838e6efa5e5b683545b01
Reviewed-on: https://go-review.googlesource.com/c/go/+/466936
Run-TryBot: Than McIntosh <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: thanm

src/cmd/link/internal/ld/lib.go

@@ -630,24 +630,30 @@ func (ctxt *Link) loadlib() {
 			}
 			if *flagLibGCC != "none" {
 				hostArchive(ctxt, *flagLibGCC)
-				// For glibc systems, the linker setup used by GCC
-				// looks like
-				//
-				//  GROUP ( /lib/x86_64-linux-gnu/libc.so.6
-				//      /usr/lib/x86_64-linux-gnu/libc_nonshared.a
-				//      AS_NEEDED ( /lib64/ld-linux-x86-64.so.2 ) )
-				//
-				// where libc_nonshared.a contains a small set of
-				// symbols including "__stack_chk_fail_local" and a
-				// few others. Thus if we are doing internal linking
-				// and "__stack_chk_fail_local" is unresolved (most
-				// likely due to the use of -fstack-protector), try
-				// loading libc_nonshared.a to resolve it.
-				isunresolved := symbolsAreUnresolved(ctxt, []string{"__stack_chk_fail_local"})
-				if isunresolved[0] {
-					if p := ctxt.findLibPath("libc_nonshared.a"); p != "none" {
-						hostArchive(ctxt, p)
-					}
+			}
+			// For glibc systems, the linker setup used by GCC
+			// looks like
+			//
+			//  GROUP ( /lib/x86_64-linux-gnu/libc.so.6
+			//      /usr/lib/x86_64-linux-gnu/libc_nonshared.a
+			//      AS_NEEDED ( /lib64/ld-linux-x86-64.so.2 ) )
+			//
+			// where libc_nonshared.a contains a small set of
+			// symbols including "__stack_chk_fail_local" and a
+			// few others. Thus if we are doing internal linking
+			// and "__stack_chk_fail_local" is unresolved (most
+			// likely due to the use of -fstack-protector), try
+			// loading libc_nonshared.a to resolve it.
+			//
+			// On Alpine Linux (musl-based), the library providing
+			// this symbol is called libssp_nonshared.a.
+			isunresolved := symbolsAreUnresolved(ctxt, []string{"__stack_chk_fail_local"})
+			if isunresolved[0] {
+				if p := ctxt.findLibPath("libc_nonshared.a"); p != "none" {
+					hostArchive(ctxt, p)
+				}
+				if p := ctxt.findLibPath("libssp_nonshared.a"); p != "none" {
+					hostArchive(ctxt, p)
 				}
 			}
 		}