[release-branch.go1.17] runtime: set vdsoSP to caller's SP consistently

m.vdsoSP should be set to the SP of the caller of nanotime1,
instead of the SP of nanotime1 itself, which matches m.vdsoPC.
Otherwise the unmatched vdsoPC and vdsoSP would make the stack
trace look like recursive.

We already do it correctly on AMD64, 386, and RISCV64. This CL
fixes the rest.

Also incorporate CL 352509, skipping a flaky test.

Updates #47324, #50772.
Fixes #50781.

Change-Id: I98b6fcfbe9fc6bdd28b8fe2a1299b7c505371dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/337590
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
(cherry picked from commit 217507eb035933bac6c990844f0d71d6000fd339)
Reviewed-on: https://go-review.googlesource.com/c/go/+/380715
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

diff --git a/src/runtime/pprof/pprof_test.go b/src/runtime/pprof/pprof_test.go
index 7c71d8263be8b8e7799ea856f65f0dcbdef1dcce..4d37cdb53c30dce8cc13e6e76d6cb42cfe17c27a 100644 (file)
--- a/src/runtime/pprof/pprof_test.go
+++ b/src/runtime/pprof/pprof_test.go
@@ -1543,3 +1543,38 @@ func TestTryAdd(t *testing.T) {
                })
        }
 }
+
+func TestTimeVDSO(t *testing.T) {
+       // Test that time functions have the right stack trace. In particular,
+       // it shouldn't be recursive.
+
+       if runtime.GOOS == "android" {
+               // Flaky on Android, issue 48655. VDSO may not be enabled.
+               testenv.SkipFlaky(t, 48655)
+       }
+
+       p := testCPUProfile(t, stackContains, []string{"time.now"}, avoidFunctions(), func(dur time.Duration) {
+               t0 := time.Now()
+               for {
+                       t := time.Now()
+                       if t.Sub(t0) >= dur {
+                               return
+                       }
+               }
+       })
+
+       // Check for recursive time.now sample.
+       for _, sample := range p.Sample {
+               var seenNow bool
+               for _, loc := range sample.Location {
+                       for _, line := range loc.Line {
+                               if line.Function.Name == "time.now" {
+                                       if seenNow {
+                                               t.Fatalf("unexpected recursive time.now")
+                                       }
+                                       seenNow = true
+                               }
+                       }
+               }
+       }
+}

diff --git a/src/runtime/sys_linux_arm.s b/src/runtime/sys_linux_arm.s
index 02a5d4a6427402cdc0981364caf157bcd82d77a0..ae99810c10299705add3163ef7e9836139a1d7f2 100644 (file)
--- a/src/runtime/sys_linux_arm.s
+++ b/src/runtime/sys_linux_arm.s
@@ -259,8 +259,9 @@ TEXT runtime·walltime(SB),NOSPLIT,$8-12
        MOVW    R1, 4(R13)
        MOVW    R2, 8(R13)
 
+       MOVW    $ret-4(FP), R2 // caller's SP
        MOVW    LR, m_vdsoPC(R5)
-       MOVW    R13, m_vdsoSP(R5)
+       MOVW    R2, m_vdsoSP(R5)
 
        MOVW    m_curg(R5), R0
 
@@ -351,8 +352,9 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$8-8
        MOVW    R1, 4(R13)
        MOVW    R2, 8(R13)
 
+       MOVW    $ret-4(FP), R2 // caller's SP
        MOVW    LR, m_vdsoPC(R5)
-       MOVW    R13, m_vdsoSP(R5)
+       MOVW    R2, m_vdsoSP(R5)
 
        MOVW    m_curg(R5), R0
 

diff --git a/src/runtime/sys_linux_arm64.s b/src/runtime/sys_linux_arm64.s
index 69ac16027800f3df0e61100b3278ee6357ed9f82..9289ad5028b403a3be8c664512c9eac855a4193c 100644 (file)
--- a/src/runtime/sys_linux_arm64.s
+++ b/src/runtime/sys_linux_arm64.s
@@ -221,8 +221,9 @@ TEXT runtime·walltime(SB),NOSPLIT,$24-12
        MOVD    R2, 8(RSP)
        MOVD    R3, 16(RSP)
 
+       MOVD    $ret-8(FP), R2 // caller's SP
        MOVD    LR, m_vdsoPC(R21)
-       MOVD    R20, m_vdsoSP(R21)
+       MOVD    R2, m_vdsoSP(R21)
 
        MOVD    m_curg(R21), R0
        CMP     g, R0
@@ -304,8 +305,9 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$24-8
        MOVD    R2, 8(RSP)
        MOVD    R3, 16(RSP)
 
+       MOVD    $ret-8(FP), R2 // caller's SP
        MOVD    LR, m_vdsoPC(R21)
-       MOVD    R20, m_vdsoSP(R21)
+       MOVD    R2, m_vdsoSP(R21)
 
        MOVD    m_curg(R21), R0
        CMP     g, R0

diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index e18d29144563fed07dfecfcb859c5f1257de0782..7529a0ed27db35e9d8489ce6f1cccfd5ecfa5538 100644 (file)
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -229,8 +229,9 @@ TEXT runtime·walltime(SB),NOSPLIT,$16-12
        MOVV    R2, 8(R29)
        MOVV    R3, 16(R29)
 
+       MOVV    $ret-8(FP), R2 // caller's SP
        MOVV    R31, m_vdsoPC(R17)
-       MOVV    R29, m_vdsoSP(R17)
+       MOVV    R2, m_vdsoSP(R17)
 
        MOVV    m_curg(R17), R4
        MOVV    g, R5
@@ -298,8 +299,9 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
        MOVV    R2, 8(R29)
        MOVV    R3, 16(R29)
 
+       MOVV    $ret-8(FP), R2 // caller's SP
        MOVV    R31, m_vdsoPC(R17)
-       MOVV    R29, m_vdsoSP(R17)
+       MOVV    R2, m_vdsoSP(R17)
 
        MOVV    m_curg(R17), R4
        MOVV    g, R5

diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index 005fa4d2b4d002acfb2a946ff72b2369580ae08a..33b6a9409c2c5b51eaf8ee0c12fcde74b8819d90 100644 (file)
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -205,8 +205,9 @@ TEXT runtime·walltime(SB),NOSPLIT,$16-12
        MOVD    R5, 40(R1)
 
        MOVD    LR, R14
+       MOVD    $ret-FIXED_FRAME(FP), R5 // caller's SP
        MOVD    R14, m_vdsoPC(R21)
-       MOVD    R15, m_vdsoSP(R21)
+       MOVD    R5, m_vdsoSP(R21)
 
        MOVD    m_curg(R21), R6
        CMP     g, R6
@@ -297,9 +298,10 @@ TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
        MOVD    R4, 32(R1)
        MOVD    R5, 40(R1)
 
-       MOVD    LR, R14         // R14 is unchanged by C code
+       MOVD    LR, R14                         // R14 is unchanged by C code
+       MOVD    $ret-FIXED_FRAME(FP), R5        // caller's SP
        MOVD    R14, m_vdsoPC(R21)
-       MOVD    R15, m_vdsoSP(R21)
+       MOVD    R5, m_vdsoSP(R21)
 
        MOVD    m_curg(R21), R6
        CMP     g, R6