[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
** Changed in: qemu
Status: Fix Committed => Fix Released
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Fix Released
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
A fix has been merged into master.
** Changed in: qemu
Status: Confirmed => Fix Committed
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Fix Committed
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Done (took a while to figure out how...)
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Confirmed
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Can you add a Tested-by: tag to the patch?
--
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devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Confirmed
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Just as a general remark, while this specific problem seems to be
solved, there may still be issues surrounding waitid().
(With this patch applied, in a rather complex environment I see bash
processes hanging in an infinite loop, with waitid involved. I am
working on isolating the problem and providing a simple test case, but
so far I have not even found the code triggering it.)
--
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Confirmed
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
** Changed in: qemu
Status: New => Confirmed
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
Confirmed
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
Re: [Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Great! Thanks for testing that.
Do you mind supplying a Tested-by tag that I can apply to the patch?
Alistair
On Mon, Dec 21, 2020 at 5:36 AM Andreas K. Hüttel
<1906...@bugs.launchpad.net> wrote:
>
> After applying this patch on top of qemu-5.2.0, I can confirm that it
> fixes the problem.
>
> Thank you!!
>
> --
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/1906193
>
> Title:
> riscv32 user mode emulation: fork return values broken
>
> Status in QEMU:
> New
>
> Bug description:
> When running in a chroot with riscv32 (on x86_64; qemu git master as
> of today):
>
> The following short program forks; the child immediately returns with
> exit(42). The parent checks for the return value - and obtains 40!
>
> gcc-10.2
>
> ===
> #include
> #include
> #include
> #include
>
> main(c, v)
>int c;
>char **v;
> {
> pid_t pid, p;
> int s, i, n;
>
> s = 0;
> pid = fork();
> if (pid == 0)
> exit(42);
>
> /* wait for the process */
> p = wait();
> if (p != pid)
> exit (255);
>
> if (WIFEXITED(s))
> {
>int r=WEXITSTATUS(s);
>if (r!=42) {
> printf("child wants to return %i (0x%X), parent received %i (0x%X),
> difference %i\n",42,42,r,r,r-42);
>}
> }
> }
> ===
>
> (riscv-ilp32 chroot) farino /tmp # ./wait-test-short
> child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
>
> ===
> (riscv-ilp32 chroot) farino /tmp # gcc --version
> gcc (Gentoo 10.2.0-r1 p2) 10.2.0
> Copyright (C) 2020 Free Software Foundation, Inc.
> Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
> gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE
> ZWECKE.
>
> (riscv-ilp32 chroot) farino /tmp # ld --version
> GNU ld (Gentoo 2.34 p6) 2.34.0
> Copyright (C) 2020 Free Software Foundation, Inc.
> This program is free software; you may redistribute it under the terms of
> the GNU General Public License version 3 or (at your option) a later
> version.
> This program has absolutely no warranty.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
>
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
After applying this patch on top of qemu-5.2.0, I can confirm that it
fixes the problem.
Thank you!!
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Thanks a lot! Will test and post the result on monday when I'm back
home.
--
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devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
I have sent a patch, you can see it here:
https://patchwork.ozlabs.org/project/qemu-devel/list/?series=221381
It seems like QEMU's waitid implementation has a bug with handling the
status.
--
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devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Here's qemu's own strace log:
farino ~ # /usr/bin/qemu-riscv32 -strace /chroot/riscv-ilp32/tmp/wait-test-short
10123 brk(NULL) = 0x00073000
10123 brk(0x00073880) = 0x00073880
10123 uname(0x407ffed8) = 0
10123 readlinkat(AT_FDCWD,"/proc/self/exe",0x407feff0,4096) = 39
10123 brk(0x00094880) = 0x00094880
10123 brk(0x00095000) = 0x00095000
10123 mprotect(0x0006e000,8192,PROT_READ) = 0
10123
clone(CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|0x11,child_stack=0x,parent_tidptr=0x,tls=0x,child_tidptr=0x00073068)
= 10125
10123
clone(CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|0x11,child_stack=0x,parent_tidptr=0x,tls=0x,child_tidptr=0x00073068)
= 0
10125 exit_group(42)
10123 waitid(0,-1,0x407fff8c,0x4) = 0
10123 statx(1,"",AT_EMPTY_PATH,STATX_BASIC_STATS,0x407ff8e8) = 0
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
10123 write(1,0x73ad0,74) = 74
10123 exit_group(0)
--
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
Here's the (abbreviated) output of strace'ing qemu:
farino ~ # strace -f /usr/bin/qemu-riscv32
/chroot/riscv-ilp32/tmp/wait-test-short
execve("/usr/bin/qemu-riscv32", ["/usr/bin/qemu-riscv32",
"/chroot/riscv-ilp32/tmp/wait-tes"...], 0x7ffd95fb1330 /* 40 vars */) = 0
[...]
[pid 16569] uname({sysname="Linux", nodename="farino", ...}) = 0
[pid 16569] lstat("/chroot", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
[pid 16569] lstat("/chroot/riscv-ilp32", {st_mode=S_IFDIR|S_ISGID|0755,
st_size=4096, ...}) = 0
[pid 16569] lstat("/chroot/riscv-ilp32/tmp", {st_mode=S_IFDIR|S_ISVTX|0777,
st_size=4096, ...}) = 0
[pid 16569] lstat("/chroot/riscv-ilp32/tmp/wait-test-short",
{st_mode=S_IFREG|0755, st_size=445632, ...}) = 0
[pid 16569] mmap(0x413f1000, 135168, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x413f1000
[pid 16569] mprotect(0x413eb000, 8192, PROT_READ) = 0
[pid 16569] rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
[pid 16569] clone(child_stack=NULL,
flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x1339710)
= 16571
strace: Process 16571 attached
[pid 16571] set_robust_list(0x1339720, 24
[pid 16569] rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
[pid 16571] <... set_robust_list resumed>) = 0
[pid 16569] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
[pid 16571] rt_sigprocmask(SIG_SETMASK, ~[ILL FPE SEGV RTMIN RT_1], ~[KILL STOP
RTMIN RT_1], 8) = 0
[pid 16571] rt_sigprocmask(SIG_BLOCK, ~[], ~[ILL FPE KILL SEGV STOP RTMIN
RT_1], 8) = 0
[pid 16571] clone(child_stack=0x7fe5b73871f0,
flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID,
parent_tid=[16572], tls=0x7fe5b7387640, child_tidptr=0x7fe5b7387910) = 16572
[pid 16571] rt_sigprocmask(SIG_SETMASK, ~[ILL FPE KILL SEGV STOP RTMIN RT_1],
NULL, 8) = 0
[pid 16571] rt_sigprocmask(SIG_SETMASK, ~[KILL STOP RTMIN RT_1], NULL, 8) = 0
[pid 16571] gettid()= 16571
[pid 16571] rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], NULL, 8) = 0
[pid 16571] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
[pid 16569] waitid(P_ALL, -1,
[pid 16571] exit_group(42) = ?
strace: Process 16572 attached
[pid 16572] +++ exited with 42 +++
[pid 16571] +++ exited with 42 +++
[pid 16569] <... waitid resumed>{si_signo=SIGCHLD, si_code=CLD_EXITED,
si_pid=16571, si_uid=0, si_status=42, si_utime=3472328296226648184,
si_stime=3475143045726351408}, WEXITED, NULL) = 0
[pid 16569] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16571,
si_uid=0, si_status=42, si_utime=0, si_stime=0} ---
[pid 16569] statx(1, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH,
STATX_BASIC_STATS, {stx_mask=STATX_BASIC_STATS|STATX_MNT_ID, stx_attributes=0,
stx_mode=S_IFCHR|0600, stx_size=0, ...}) = 0
[pid 16569] write(1, "child wants to return 42 (0x2A),"..., 74child wants to
return 42 (0x2A), parent received 40 (0x28), difference -2
) = 74
[pid 16569] brk(0x13c1000) = 0x13c1000
[pid 16569] brk(0x13c) = 0x13c
[pid 16569] exit_group(0) = ?
[pid 16570] <... futex resumed>)= ?
[pid 16570] +++ exited with 0 +++
+++ exited with 0 +++
--
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https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
I can confirm that the same binary works fine with qemu system
emulation:
(riscv-ilp32 qemu) (none) /tmp # ./wait-test-short
(riscv-ilp32 qemu) (none) /tmp #
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
[Bug 1906193] Re: riscv32 user mode emulation: fork return values broken
This is the (statically linked) binary resulting from the source; with
it the problem can be demonstrated "standalone", without any other rv32
libraries or a complete chroot, just running the binary with qemu-
riscv32.
Generated with
(riscv-ilp32 chroot) farino /tmp # gcc -static -o wait-test-short -g
wait-test-short.c
** Attachment added: "wait-test-short"
https://bugs.launchpad.net/qemu/+bug/1906193/+attachment/5441136/+files/wait-test-short
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1906193
Title:
riscv32 user mode emulation: fork return values broken
Status in QEMU:
New
Bug description:
When running in a chroot with riscv32 (on x86_64; qemu git master as
of today):
The following short program forks; the child immediately returns with
exit(42). The parent checks for the return value - and obtains 40!
gcc-10.2
===
#include
#include
#include
#include
main(c, v)
int c;
char **v;
{
pid_t pid, p;
int s, i, n;
s = 0;
pid = fork();
if (pid == 0)
exit(42);
/* wait for the process */
p = wait();
if (p != pid)
exit (255);
if (WIFEXITED(s))
{
int r=WEXITSTATUS(s);
if (r!=42) {
printf("child wants to return %i (0x%X), parent received %i (0x%X),
difference %i\n",42,42,r,r,r-42);
}
}
}
===
(riscv-ilp32 chroot) farino /tmp # ./wait-test-short
child wants to return 42 (0x2A), parent received 40 (0x28), difference -2
===
(riscv-ilp32 chroot) farino /tmp # gcc --version
gcc (Gentoo 10.2.0-r1 p2) 10.2.0
Copyright (C) 2020 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.
(riscv-ilp32 chroot) farino /tmp # ld --version
GNU ld (Gentoo 2.34 p6) 2.34.0
Copyright (C) 2020 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1906193/+subscriptions
