cmd/link, runtime: reserve 48 bytes in stack frame for ppc64

[zte-majiang]

C functions requires 48 bytes of space on caller stack frame for ppc64. Without this fix, a simple cgo program(build with CGO_CFLAGS="-O0") could mess the stack and finally trigger a segmentation fault.

Updates #13192

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here (e.g. I signed it!) and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[laboger]

Should this be linux only? @Helflym

[Helflym]

I don't think you need to change the whole Go stack. The Go stack is relatively independent from the C stack as far as I know. You should be able to directly use cgoCalleeStackSize and asmcgocallSaveOffset constantes as it's done for AIX.
Changing the FIXED_FRAME seems a bit risky and if it's needed anyway, I'll have to check on AIX. But I'm not sure it will work.
@zte-majiang could you try without changing FIXED_FRAME and keep us updated ?

[zte-majiang]

@Helflym Thanks for the advice. I have tried the plan(only adjust the parts of go stack) some days ago, it seemed not working.
A quick search show that there are more than 3 pieces of code that try to set the minimum frame size. So I gave up the plan (which adjust go stack only), and turn to make sure the minimum frame size is always 48 on both side.
In my opinion, it's more clear to keep C and GO stack frames consistent. Or else, there will be two minimum frame sizes, one for GO which is 32, and one for C which is 48. This might make things complex(for example, stack backtrace? I'm not sure).
I will have a try as you suggested tomorrow.

[googlebot]

CLAs look good, thanks!

ℹ️ Googlers: Go here for more info.

[gopherbot]

This PR (HEAD: 3b6ffd0) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/go/+/174317 to see it.

Tip: You can toggle comments from me using the comments slash command (e.g. /comments off)
See the Wiki page for more info

[gopherbot]

Message from Lynn Boger:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Lynn Boger:

Patch Set 1:

(4 comments)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Cherry Zhang:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Clément Chigot:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

This PR (HEAD: 2a9abfc) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/go/+/174317 to see it.

Tip: You can toggle comments from me using the comments slash command (e.g. /comments off)
See the Wiki page for more info

[gopherbot]

Message from Jiang Ma:

Patch Set 1:

(5 comments)

Dear Reviewers:
Thanks for the advices. I have adjusted the patch as you suggested.
Please take a look at the new one. It is ok now?

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Lynn Boger:

Patch Set 2:

Did you run all.bash on this patch? I tried this on a power8 linux/ppc64 RHEL 7 and got failures.

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Lynn Boger:

Patch Set 2:

Patch Set 2:

Did you run all.bash on this patch? I tried this on a power8 linux/ppc64 RHEL 7 and got failures.

Clarification: I ran all.bash against patchset 1 and there were failures. It looks like several changes from patchset 1 were removed in patchset 2. Was that your intention?

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Jiang Ma:

Patch Set 2:

Patch Set 2:

Patch Set 2:

Did you run all.bash on this patch? I tried this on a power8 linux/ppc64 RHEL 7 and got failures.

Clarification: I ran all.bash against patchset 1 and there were failures. It looks like several changes from patchset 1 were removed in patchset 2. Was that your intention?
Yes, Changes about adjusting golang frames were removed as suggested.
Could you try patchset 2? I can not run all.bash as I have no power8 machines...
I ran make.bash(and my cgo test program with the help of the user model qemu) successfully on a linux/amd64 ubuntu18.04.

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Carlos Eduardo Seo:

Patch Set 2:

Could you please rebase this against master? I could run a test on a POWER8 BE system.

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Cherry Mui:

Patch Set 1:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/174317.
After addressing review feedback, remember to publish your drafts!