From: "Alex Bennée" <alex.bennee@linaro.org>
To: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>,
Peter Maydell <peter.maydell@linaro.org>,
Bug 1880225 <1880225@bugs.launchpad.net>,
Riku Voipio <riku.voipio@iki.fi>,
Richard Henderson <richard.henderson@linaro.org>,
Laurent Vivier <laurent@vivier.eu>,
qemu-arm@nongnu.org
Subject: Re: [PATCH v1 2/3] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit
Date: Wed, 27 May 2020 17:14:43 +0100 [thread overview]
Message-ID: <87pnap5p8s.fsf@linaro.org> (raw)
In-Reply-To: <CAHiYmc7TYHMcitiG9ELxfz-EC8DSG1b7FeFsxXxTbu-7FSih=Q@mail.gmail.com>
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> writes:
> сре, 27. мај 2020. у 14:05 Aleksandar Markovic
> <aleksandar.qemu.devel@gmail.com> је написао/ла:
>>
>> сре, 27. мај 2020. у 12:07 Alex Bennée <alex.bennee@linaro.org> је написао/ла:
>> >
>> > We rely on the pointer to wrap when accessing the high address of the
>> > COMMPAGE so it lands somewhere reasonable. However on 32 bit hosts we
>> > cannot afford just to map the entire 4gb address range. The old mmap
>> > trial and error code handled this by just checking we could map both
>> > the guest_base and the computed COMMPAGE address.
>> >
>> > We can't just manipulate loadaddr to get what we want so we introduce
>> > an offset which pgb_find_hole can apply when looking for a gap for
>> > guest_base that ensures there is space left to map the COMMPAGE
>> > afterwards.
>> >
>> > This is arguably a little inefficient for the one 32 bit
>> > value (kuser_helper_version) we need to keep there given all the
>> > actual code entries are picked up during the translation phase.
>> >
>> > Fixes: ee94743034b
>> > Bug: https://bugs.launchpad.net/qemu/+bug/1880225
>>
>> For the scenario in this bug report, for today's master, before and after
>> applying this patch:
>>
>
> I am not sure how significant is this info, but I executed the test
> without applying patch 1/3, so only 2/3 was applied in the case
> "AFTER".
That is expected. The other fix only affects binaries run inside a
/proc-less chroot and the final patch is a test case for COMMPAGE
support.
--
Alex Bennée
WARNING: multiple messages have this Message-ID (diff)
From: "Alex Bennée" <alex.bennee@linaro.org>
To: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>,
Bug 1880225 <1880225@bugs.launchpad.net>,
Riku Voipio <riku.voipio@iki.fi>,
Richard Henderson <richard.henderson@linaro.org>,
QEMU Developers <qemu-devel@nongnu.org>,
Laurent Vivier <laurent@vivier.eu>,
qemu-arm@nongnu.org
Subject: Re: [PATCH v1 2/3] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit
Date: Wed, 27 May 2020 17:14:43 +0100 [thread overview]
Message-ID: <87pnap5p8s.fsf@linaro.org> (raw)
In-Reply-To: <CAHiYmc7TYHMcitiG9ELxfz-EC8DSG1b7FeFsxXxTbu-7FSih=Q@mail.gmail.com>
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> writes:
> сре, 27. мај 2020. у 14:05 Aleksandar Markovic
> <aleksandar.qemu.devel@gmail.com> је написао/ла:
>>
>> сре, 27. мај 2020. у 12:07 Alex Bennée <alex.bennee@linaro.org> је написао/ла:
>> >
>> > We rely on the pointer to wrap when accessing the high address of the
>> > COMMPAGE so it lands somewhere reasonable. However on 32 bit hosts we
>> > cannot afford just to map the entire 4gb address range. The old mmap
>> > trial and error code handled this by just checking we could map both
>> > the guest_base and the computed COMMPAGE address.
>> >
>> > We can't just manipulate loadaddr to get what we want so we introduce
>> > an offset which pgb_find_hole can apply when looking for a gap for
>> > guest_base that ensures there is space left to map the COMMPAGE
>> > afterwards.
>> >
>> > This is arguably a little inefficient for the one 32 bit
>> > value (kuser_helper_version) we need to keep there given all the
>> > actual code entries are picked up during the translation phase.
>> >
>> > Fixes: ee94743034b
>> > Bug: https://bugs.launchpad.net/qemu/+bug/1880225
>>
>> For the scenario in this bug report, for today's master, before and after
>> applying this patch:
>>
>
> I am not sure how significant is this info, but I executed the test
> without applying patch 1/3, so only 2/3 was applied in the case
> "AFTER".
That is expected. The other fix only affects binaries run inside a
/proc-less chroot and the final patch is a test case for COMMPAGE
support.
--
Alex Bennée
WARNING: multiple messages have this Message-ID (diff)
From: "Alex Bennée" <1880225@bugs.launchpad.net>
To: qemu-devel@nongnu.org
Subject: [Bug 1880225] Re: [PATCH v1 2/3] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit
Date: Wed, 27 May 2020 16:14:43 -0000 [thread overview]
Message-ID: <87pnap5p8s.fsf@linaro.org> (raw)
Message-ID: <20200527161443.uTeMIhasg3u8eFKg7j4tJ4nttt400HvCd1ODrrwU2xE@z> (raw)
In-Reply-To: CAHiYmc7TYHMcitiG9ELxfz-EC8DSG1b7FeFsxXxTbu-7FSih=Q@mail.gmail.com
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> writes:
> сре, 27. мај 2020. у 14:05 Aleksandar Markovic
> <aleksandar.qemu.devel@gmail.com> је написао/ла:
>>
>> сре, 27. мај 2020. у 12:07 Alex Bennée <alex.bennee@linaro.org> је написао/ла:
>> >
>> > We rely on the pointer to wrap when accessing the high address of the
>> > COMMPAGE so it lands somewhere reasonable. However on 32 bit hosts we
>> > cannot afford just to map the entire 4gb address range. The old mmap
>> > trial and error code handled this by just checking we could map both
>> > the guest_base and the computed COMMPAGE address.
>> >
>> > We can't just manipulate loadaddr to get what we want so we introduce
>> > an offset which pgb_find_hole can apply when looking for a gap for
>> > guest_base that ensures there is space left to map the COMMPAGE
>> > afterwards.
>> >
>> > This is arguably a little inefficient for the one 32 bit
>> > value (kuser_helper_version) we need to keep there given all the
>> > actual code entries are picked up during the translation phase.
>> >
>> > Fixes: ee94743034b
>> > Bug: https://bugs.launchpad.net/qemu/+bug/1880225
>>
>> For the scenario in this bug report, for today's master, before and after
>> applying this patch:
>>
>
> I am not sure how significant is this info, but I executed the test
> without applying patch 1/3, so only 2/3 was applied in the case
> "AFTER".
That is expected. The other fix only affects binaries run inside a
/proc-less chroot and the final patch is a test case for COMMPAGE
support.
--
Alex Bennée
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1880225
Title:
Emulation of some arm programs fail with "Assertion `have_guest_base'
failed."
Status in QEMU:
In Progress
Bug description:
This issue is observer with QEMU ToT, checked out around May 15th (but
I believe it is present in current master too), and wasn't present in
QEMU v5.0.0.
I am using 32-bit Intel(R) Pentium(R) M processor 1.73GHz host.
Arm cross-compiler is a standard cross-compiler that comes with
Debian-based distributions, and gcc version is:
$ arm-linux-gnueabi-gcc --version
arm-linux-gnueabi-gcc (Debian 8.3.0-2) 8.3.0
Compile this program with cross compiler:
$ arm-linux-gnueabi-gcc -O2 -static toupper_string.c -o
toupper_string-arm
Emulation with QEMU v5.0.0 is correct, and gives expected output:
$ ~/Build/qemu-5.0.0/build-gcc/arm-linux-user/qemu-arm ./toupper_string-arm
CONTROL RESULT: (toupper_string)
nwlrbbmqbhcdarz owkkyhiddqscdxr jmowfrxsjybldbe fsarcbynecdyggx xpklorellnmpapq
NWLRBBMQBHCDARZ OWKKYHIDDQSCDXR JMOWFRXSJYBLDBE FSARCBYNECDYGGX XPKLORELLNMPAPQ
While, in case of QEMU master it fails:
$ ~/Build/qemu-master/build-gcc/arm-linux-user/qemu-arm ./toupper_string-arm
qemu-arm: /home/rtrk/Build/qemu-master/linux-user/elfload.c:2294: probe_guest_base: Assertion `have_guest_base' failed.
Aborted
There are many other programs that exibit the same behavior. The
failure is arm-sprecific.
-----------------------------------------------------
source code: (let's call this file toupper_string.c) (similar file is
also in attachment)
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#define MAX_STRING_LENGHT 15
#define NUMBER_OF_RANDOM_STRINGS 100
#define DEFAULT_NUMBER_OF_REPETITIONS 30000
#define MAX_NUMBER_OF_REPETITIONS 1000000000
#define NUMBER_OF_CONTROL_PRINT_ITEMS 5
/* Structure for keeping an array of strings */
struct StringStruct {
char chars[MAX_STRING_LENGHT + 1];
};
/**
* Sets characters of the given string to random small letters a-z.
* @param s String to get random characters.
* @len Length of the input string.
*/
static void gen_random_string(char *chars, const int len)
{
static const char letters[] = "abcdefghijklmnopqrstuvwxyz";
for (size_t i = 0; i < len; i++) {
chars[i] = letters[rand() % (sizeof(letters) - 1)];
}
chars[len] = 0;
}
void main (int argc, char* argv[])
{
struct StringStruct random_strings[NUMBER_OF_RANDOM_STRINGS];
struct StringStruct strings_to_be_uppercased[NUMBER_OF_RANDOM_STRINGS];
int32_t number_of_repetitions = DEFAULT_NUMBER_OF_REPETITIONS;
int32_t option;
/* Parse command line options */
while ((option = getopt(argc, argv, "n:")) != -1) {
if (option == 'n') {
int32_t user_number_of_repetitions = atoi(optarg);
/* Check if the value is a negative number */
if (user_number_of_repetitions < 1) {
fprintf(stderr, "Error ... Value for option '-n' cannot be a "
"negative number.\n");
exit(EXIT_FAILURE);
}
/* Check if the value is a string or zero */
if (user_number_of_repetitions == 0) {
fprintf(stderr, "Error ... Invalid value for option '-n'.\n");
exit(EXIT_FAILURE);
}
/* Check if the value is too large */
if (user_number_of_repetitions > MAX_NUMBER_OF_REPETITIONS) {
fprintf(stderr, "Error ... Value for option '-n' cannot be "
"more than %d.\n", MAX_NUMBER_OF_REPETITIONS);
exit(EXIT_FAILURE);
}
number_of_repetitions = user_number_of_repetitions;
} else {
exit(EXIT_FAILURE);
}
}
/* Create an array of strings with random content */
srand(1);
for (size_t i = 0; i < NUMBER_OF_RANDOM_STRINGS; i++) {
gen_random_string(random_strings[i].chars, MAX_STRING_LENGHT);
}
/* Perform uppercasing of a set of random strings multiple times */
for (size_t j = 0; j < number_of_repetitions; j++) {
/* Copy initial set of random strings to the set to be uppercased */
memcpy(strings_to_be_uppercased, random_strings,
NUMBER_OF_RANDOM_STRINGS * (MAX_STRING_LENGHT + 1));
/* Do actual changing case to uppercase */
for (size_t i = 0; i < NUMBER_OF_RANDOM_STRINGS; i++) {
int k = 0;
while (strings_to_be_uppercased[i].chars[k]) {
char ch = strings_to_be_uppercased[i].chars[k] - 32;
memcpy((void *)strings_to_be_uppercased[i].chars + k,
&ch, 1);
k++;
}
}
}
/* Control printing */
printf("CONTROL RESULT: (toupper_string)\n");
for (size_t i = 0; i < NUMBER_OF_CONTROL_PRINT_ITEMS; i++) {
printf(" %s", random_strings[i].chars);
}
printf("\n");
for (size_t i = 0; i < NUMBER_OF_CONTROL_PRINT_ITEMS; i++) {
printf(" %s", strings_to_be_uppercased[i].chars);
}
printf("\n");
}
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1880225/+subscriptions
next prev parent reply other threads:[~2020-05-27 16:14 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 10:05 [PATCH v1 0/3] some linux-user guest_base fixes Alex Bennée
2020-05-27 10:05 ` [PATCH v1 1/3] linux-user: provide fallback pgd_find_hole for bare chroots Alex Bennée
2020-05-27 10:05 ` Alex Bennée
2020-06-02 0:37 ` Richard Henderson
2020-06-02 0:37 ` Richard Henderson
2020-05-27 10:05 ` [PATCH v1 2/3] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit Alex Bennée
2020-05-27 10:05 ` [Bug 1880225] " Alex Bennée
2020-05-27 10:05 ` Alex Bennée
2020-05-27 12:05 ` Aleksandar Markovic
2020-05-27 12:05 ` [Bug 1880225] " Aleksandar Markovic
2020-05-27 12:05 ` Aleksandar Markovic
2020-05-27 14:47 ` Aleksandar Markovic
2020-05-27 14:47 ` [Bug 1880225] " Aleksandar Markovic
2020-05-27 14:47 ` Aleksandar Markovic
2020-05-27 16:14 ` Alex Bennée [this message]
2020-05-27 16:14 ` [Bug 1880225] " Alex Bennée
2020-05-27 16:14 ` Alex Bennée
2020-06-02 0:28 ` Richard Henderson
2020-06-02 0:28 ` Richard Henderson
2020-06-05 9:45 ` Alex Bennée
2020-06-05 9:45 ` [Bug 1880225] " Alex Bennée
2020-06-05 9:45 ` Alex Bennée
2020-06-05 10:24 ` Alex Bennée
2020-06-05 10:24 ` [Bug 1880225] " Alex Bennée
2020-06-05 10:24 ` Alex Bennée
2020-05-27 10:05 ` [PATCH v1 3/3] tests/tcg: add simple commpage test case Alex Bennée
2020-05-27 10:05 ` Alex Bennée
2020-06-02 0:40 ` Richard Henderson
2020-05-27 14:12 ` [PATCH v1 0/3] some linux-user guest_base fixes no-reply
2020-05-27 14:12 ` no-reply
-- strict thread matches above, loose matches on Subject: below --
2020-06-09 10:37 [PULL 00/17] testing and misc fixes Alex Bennée
2020-06-09 10:37 ` [PULL 01/17] qemu-plugin.h: add missing include <stddef.h> to define size_t Alex Bennée
2020-06-09 10:37 ` [PULL 02/17] scripts/clean-includes: Mark 'qemu/qemu-plugin.h' as special header Alex Bennée
2020-06-09 10:37 ` [PULL 03/17] tests/plugin: correctly honour io_count Alex Bennée
2020-06-09 10:37 ` [PULL 04/17] exec: flush the whole TLB if a watchpoint crosses a page boundary Alex Bennée
2020-06-09 10:37 ` [PULL 05/17] .travis.yml: allow failure for unreliable hosts Alex Bennée
2020-06-09 10:37 ` [PULL 06/17] .shippable: temporaily disable some cross builds Alex Bennée
2020-06-09 10:37 ` [PULL 07/17] tests/docker: fix pre-requisite for debian-tricore-cross Alex Bennée
2020-06-09 10:38 ` [PULL 08/17] docker: update Ubuntu to 20.04 Alex Bennée
2020-06-09 10:38 ` [PULL 09/17] hw/virtio/vhost: re-factor vhost-section and allow DIRTY_MEMORY_CODE Alex Bennée
2020-06-09 10:38 ` [PULL 10/17] linux-user: provide fallback pgd_find_hole for bare chroots Alex Bennée
2020-06-09 10:38 ` [PULL 11/17] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit Alex Bennée
2020-06-09 10:38 ` [Bug 1880225] " Alex Bennée
2020-06-09 10:38 ` [PULL 12/17] tests/tcg: add simple commpage test case Alex Bennée
2020-06-09 10:38 ` Alex Bennée
2020-06-09 10:38 ` [PULL 13/17] linux-user: detect overflow of MAP_FIXED mmap Alex Bennée
2020-06-09 10:38 ` [PULL 14/17] tests/docker: Remove flex/bison packages Alex Bennée
2020-06-09 10:38 ` [PULL 15/17] tests/vm: " Alex Bennée
2020-06-09 10:53 ` Claudio Fontana
2020-06-09 11:08 ` Alex Bennée
2020-06-09 10:38 ` [PULL 16/17] cirrus-ci: " Alex Bennée
2020-06-09 10:38 ` [PULL 17/17] scripts/coverity-scan: " Alex Bennée
2020-06-11 10:20 ` [PULL 00/17] testing and misc fixes Peter Maydell
2020-06-05 15:49 [PATCH v1 00/14] various fixes for next PR (testing, vhost, guest_base fixes) Alex Bennée
2020-06-05 15:49 ` [PATCH v1 01/14] qemu-plugin.h: add missing include <stddef.h> to define size_t Alex Bennée
2020-06-05 15:49 ` [PATCH v1 02/14] scripts/clean-includes: Mark 'qemu/qemu-plugin.h' as special header Alex Bennée
2020-06-05 15:49 ` [PATCH v1 03/14] tests/plugin: correctly honour io_count Alex Bennée
2020-06-05 15:49 ` [PATCH v1 04/14] exec: flush the whole TLB if a watchpoint crosses a page boundary Alex Bennée
2020-06-05 15:49 ` [PATCH v1 05/14] .travis.yml: allow failure for unreliable hosts Alex Bennée
2020-06-05 15:49 ` [PATCH v1 06/14] .shippable: temporaily disable some cross builds Alex Bennée
2020-06-05 16:12 ` Philippe Mathieu-Daudé
2020-06-05 15:49 ` [PATCH v1 07/14] iotests: 194: wait migration completion on target too Alex Bennée
2020-06-05 15:49 ` [PATCH v1 08/14] tests/docker: fix pre-requisite for debian-tricore-cross Alex Bennée
2020-06-05 15:49 ` [PATCH v1 09/14] docker: update Ubuntu to 20.04 Alex Bennée
2020-06-05 15:49 ` [PATCH v1 10/14] hw/virtio/vhost: re-factor vhost-section and allow DIRTY_MEMORY_CODE Alex Bennée
2020-06-05 15:49 ` [PATCH v1 11/14] linux-user: provide fallback pgd_find_hole for bare chroots Alex Bennée
2020-06-05 15:49 ` [PATCH v1 12/14] linux-user: deal with address wrap for ARM_COMMPAGE on 32 bit Alex Bennée
2020-06-05 15:49 ` [Bug 1880225] " Alex Bennée
2020-06-05 15:49 ` [PATCH v1 13/14] tests/tcg: add simple commpage test case Alex Bennée
2020-06-05 15:49 ` Alex Bennée
2020-06-05 15:49 ` [PATCH v1 14/14] linux-user: detect overflow of MAP_FIXED mmap Alex Bennée
2020-06-05 16:16 ` Philippe Mathieu-Daudé
2020-06-05 15:54 ` [PATCH v1 00/14] various fixes for next PR (testing, vhost, guest_base fixes) Eric Blake
2020-06-05 17:46 ` no-reply
2020-06-07 6:55 ` Thomas Huth
2020-06-08 15:58 ` Alex Bennée
2020-05-22 18:43 [Bug 1880225] [NEW] Emulation of some arm programs fail with "Assertion `have_guest_base' failed." Aleksandar Markovic
2020-05-22 19:18 ` Alex Bennée
2020-05-22 19:18 ` Alex Bennée
2020-05-22 19:27 ` [Bug 1880225] " Alex Bennée
2020-05-23 1:07 ` Aleksandar Markovic
2020-05-23 1:14 ` Aleksandar Markovic
2020-05-23 7:40 ` Alex Bennée
2020-05-23 7:40 ` Alex Bennée
2020-05-23 1:31 ` Aleksandar Markovic
2020-05-23 7:50 ` Alex Bennée
2020-05-23 7:52 ` Aleksandar Markovic
2020-05-23 10:14 ` Alex Bennée
2020-08-20 15:08 ` Thomas Huth
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