Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

runtime: add debugger hook for fatal signals

Browse source 
On Go <= 1.20 signals that caused the program to exit would eventually
call runtime.fatal. After the changes made in go.dev/cl/462437 but it
would still be nice if debuggers (eg. Delve) had a function they could
hook to intercept fatal signals.

Change-Id: Icf2b65187f95d52e60825c84f386806a75b38f6e
Reviewed-on: https://go-review.googlesource.com/c/go/+/495736
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
This commit is contained in:
Alessandro Arzilli 2023-05-17 15:33:07 +02:00 • committed by Gopher Robot
parent 587c1c191a
commit d8c9eece28
1 changed files with 43 additions and 38 deletions
Download patch file Download diff file Expand all files Collapse all files

81
src/runtime/signal_unix.go
View file

@ -734,44 +734,7 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
startpanic_m()
}
if sig < uint32(len(sigtable)) {
print(sigtable[sig].name, "\n")
} else {
print("Signal ", sig, "\n")
}
print("PC=", hex(c.sigpc()), " m=", mp.id, " sigcode=", c.sigcode(), "\n")
if mp.incgo && gp == mp.g0 && mp.curg != nil {
print("signal arrived during cgo execution\n")
// Switch to curg so that we get a traceback of the Go code
// leading up to the cgocall, which switched from curg to g0.
gp = mp.curg
}
if sig == _SIGILL || sig == _SIGFPE {
// It would be nice to know how long the instruction is.
// Unfortunately, that's complicated to do in general (mostly for x86
// and s930x, but other archs have non-standard instruction lengths also).
// Opt to print 16 bytes, which covers most instructions.
const maxN = 16
n := uintptr(maxN)
// We have to be careful, though. If we're near the end of
// a page and the following page isn't mapped, we could
// segfault. So make sure we don't straddle a page (even though
// that could lead to printing an incomplete instruction).
// We're assuming here we can read at least the page containing the PC.
// I suppose it is possible that the page is mapped executable but not readable?
pc := c.sigpc()
if n > physPageSize-pc%physPageSize {
n = physPageSize - pc%physPageSize
}
print("instruction bytes:")
b := (*[maxN]byte)(unsafe.Pointer(pc))
for i := uintptr(0); i < n; i++ {
print(" ", hex(b[i]))
}
println()
}
print("\n")
gp = fatalsignal(sig, c, gp, mp)
level, _, docrash := gotraceback()
if level > 0 {
@ -813,6 +776,48 @@ func sighandler(sig uint32, info *siginfo, ctxt unsafe.Pointer, gp *g) {
exit(2)
}
func fatalsignal(sig uint32, c *sigctxt, gp *g, mp *m) *g {
if sig < uint32(len(sigtable)) {
print(sigtable[sig].name, "\n")
} else {
print("Signal ", sig, "\n")
}
print("PC=", hex(c.sigpc()), " m=", mp.id, " sigcode=", c.sigcode(), "\n")
if mp.incgo && gp == mp.g0 && mp.curg != nil {
print("signal arrived during cgo execution\n")
// Switch to curg so that we get a traceback of the Go code
// leading up to the cgocall, which switched from curg to g0.
gp = mp.curg
}
if sig == _SIGILL || sig == _SIGFPE {
// It would be nice to know how long the instruction is.
// Unfortunately, that's complicated to do in general (mostly for x86
// and s930x, but other archs have non-standard instruction lengths also).
// Opt to print 16 bytes, which covers most instructions.
const maxN = 16
n := uintptr(maxN)
// We have to be careful, though. If we're near the end of
// a page and the following page isn't mapped, we could
// segfault. So make sure we don't straddle a page (even though
// that could lead to printing an incomplete instruction).
// We're assuming here we can read at least the page containing the PC.
// I suppose it is possible that the page is mapped executable but not readable?
pc := c.sigpc()
if n > physPageSize-pc%physPageSize {
n = physPageSize - pc%physPageSize
}
print("instruction bytes:")
b := (*[maxN]byte)(unsafe.Pointer(pc))
for i := uintptr(0); i < n; i++ {
print(" ", hex(b[i]))
}
println()
}
print("\n")
return gp
}
// sigpanic turns a synchronous signal into a run-time panic.
// If the signal handler sees a synchronous panic, it arranges the
// stack to look like the function where the signal occurred called