Re: [PATCH] vasnprintf: Don't use %n on android
On 23.01.19 01:25, Bruno Haible wrote: > Hi Tim and Hugo, > >>> I also don't see much here (Debian unstable): >>> >>> $ grep -A1 -i 'checking.*printf' config.log >>> configure:6305: checking for vasnprintf >>> configure:6305: result: no >>> configure:6305: checking for snprintf >>> configure:6305: result: yes >>> -- >>> configure:8450: checking whether snprintf returns a byte count as in C99 >>> configure:8548: result: yes >>> configure:8559: checking for snprintf >>> configure:8559: result: yes >>> -- >>> configure:8568: checking whether _snprintf is declared >>> configure:8568: result: no >>> >>> What does that grep look for you ? >> >> $ grep -A1 'checking .*printf' config.log >> configure:6326: checking for vasnprintf >> configure:6326: gcc -o conftest -g -O2 conftest.c >&5 >> -- >> configure:6326: checking for snprintf >> configure:6326: gcc -o conftest -g -O2 conftest.c >&5 >> -- >> configure:8471: checking whether snprintf returns a byte count as in C99 >> configure:8558: gcc -o conftest -g -O2 conftest.c >&5 >> -- >> configure:8580: checking for snprintf >> configure:8580: result: yes >> -- >> configure:8589: checking whether _snprintf is declared >> configure:8589: gcc -c -g -O2 conftest.c >&5 > > I did these steps: > 1) Create a testdir >./gnulib-tool --create-testdir --dir=../testdir-printf-posix > --single-configure \ > dprintf-posix fprintf-posix printf-posix snprintf-posix \ > sprintf-posix vasnprintf-posix vasprintf-posix > vdprintf-posix \ > vfprintf-posix vprintf-posix vsnprintf-posix vsprintf-posix > 2) Tarred the resulting directory > 3) Transfered it to the device (Android 4.3 with 'Terminal IDE' app in my > case), > 4) Unpacked it there, > 5) configured it, > 6) Copy&pasted the configure output. > > The configure output contains the lines > > checking whether printf supports size specifiers as in C99... yes > checking whether printf supports 'long double' arguments... yes > checking whether printf supports infinite 'double' arguments... no > checking whether printf supports infinite 'long double' arguments... no > checking whether printf supports the 'a' and 'A' directives... no > checking whether printf supports the 'F' directive... no > checking whether printf supports the 'n' directive... no > checking whether printf supports the 'ls' directive... no > checking whether printf supports POSIX/XSI format strings with positions... > yes > checking whether printf supports the grouping flag... no > checking whether printf supports the left-adjust flag correctly... yes > checking whether printf supports the zero flag correctly... no > checking whether printf supports large precisions... yes > checking whether printf survives out-of-memory conditions... no > checking for snprintf... yes > checking whether snprintf truncates the result as in C99... yes > checking whether snprintf returns a byte count as in C99... yes > checking whether snprintf fully supports the 'n' directive... no > checking whether snprintf respects a size of 1... yes > checking whether vsnprintf respects a zero size as in C99... yes > > With this, I am in the position to update the results in printf.m4, and > even add cross-compilation guesses. > > Since snprintf is behaving well enough, we can disable the use of %n, > like you suggested. > > Done through the attached patches. > > Bruno Thanks you, Bruno and Hugo. Already committed it successfully into GnuTLS :-) Regards, Tim signature.asc Description: OpenPGP digital signature
Re: [PATCH] vasnprintf: Don't use %n on android
Hi Tim and Hugo, > > I also don't see much here (Debian unstable): > > > > $ grep -A1 -i 'checking.*printf' config.log > > configure:6305: checking for vasnprintf > > configure:6305: result: no > > configure:6305: checking for snprintf > > configure:6305: result: yes > > -- > > configure:8450: checking whether snprintf returns a byte count as in C99 > > configure:8548: result: yes > > configure:8559: checking for snprintf > > configure:8559: result: yes > > -- > > configure:8568: checking whether _snprintf is declared > > configure:8568: result: no > > > > What does that grep look for you ? > > $ grep -A1 'checking .*printf' config.log > configure:6326: checking for vasnprintf > configure:6326: gcc -o conftest -g -O2 conftest.c >&5 > -- > configure:6326: checking for snprintf > configure:6326: gcc -o conftest -g -O2 conftest.c >&5 > -- > configure:8471: checking whether snprintf returns a byte count as in C99 > configure:8558: gcc -o conftest -g -O2 conftest.c >&5 > -- > configure:8580: checking for snprintf > configure:8580: result: yes > -- > configure:8589: checking whether _snprintf is declared > configure:8589: gcc -c -g -O2 conftest.c >&5 I did these steps: 1) Create a testdir ./gnulib-tool --create-testdir --dir=../testdir-printf-posix --single-configure \ dprintf-posix fprintf-posix printf-posix snprintf-posix \ sprintf-posix vasnprintf-posix vasprintf-posix vdprintf-posix \ vfprintf-posix vprintf-posix vsnprintf-posix vsprintf-posix 2) Tarred the resulting directory 3) Transfered it to the device (Android 4.3 with 'Terminal IDE' app in my case), 4) Unpacked it there, 5) configured it, 6) Copy&pasted the configure output. The configure output contains the lines checking whether printf supports size specifiers as in C99... yes checking whether printf supports 'long double' arguments... yes checking whether printf supports infinite 'double' arguments... no checking whether printf supports infinite 'long double' arguments... no checking whether printf supports the 'a' and 'A' directives... no checking whether printf supports the 'F' directive... no checking whether printf supports the 'n' directive... no checking whether printf supports the 'ls' directive... no checking whether printf supports POSIX/XSI format strings with positions... yes checking whether printf supports the grouping flag... no checking whether printf supports the left-adjust flag correctly... yes checking whether printf supports the zero flag correctly... no checking whether printf supports large precisions... yes checking whether printf survives out-of-memory conditions... no checking for snprintf... yes checking whether snprintf truncates the result as in C99... yes checking whether snprintf returns a byte count as in C99... yes checking whether snprintf fully supports the 'n' directive... no checking whether snprintf respects a size of 1... yes checking whether vsnprintf respects a zero size as in C99... yes With this, I am in the position to update the results in printf.m4, and even add cross-compilation guesses. Since snprintf is behaving well enough, we can disable the use of %n, like you suggested. Done through the attached patches. Bruno >From 5447f440ef927283e63d5a1290dab292f7af1aea Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Tue, 22 Jan 2019 22:44:49 +0100 Subject: [PATCH 1/2] *printf: Support cross-compilation to Android. * m4/printf.m4: Add cross-compilation guesses for Android. --- ChangeLog| 5 ++ m4/printf.m4 | 190 --- 2 files changed, 120 insertions(+), 75 deletions(-) diff --git a/ChangeLog b/ChangeLog index c496144..e3ec57b 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2019-01-22 Bruno Haible + + *printf: Support cross-compilation to Android. + * m4/printf.m4: Add cross-compilation guesses for Android. + 2019-01-21 Bruno Haible diacrit: Mark deprecated. diff --git a/m4/printf.m4 b/m4/printf.m4 index 1db13bf..cbf6ae4 100644 --- a/m4/printf.m4 +++ b/m4/printf.m4 @@ -1,4 +1,4 @@ -# printf.m4 serial 59 +# printf.m4 serial 60 dnl Copyright (C) 2003, 2007-2019 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -79,6 +79,8 @@ changequote(,)dnl netbsd[1-2]* | netbsdelf[1-2]* | netbsdaout[1-2]* | netbsdcoff[1-2]*) gl_cv_func_printf_sizes_c99="guessing no";; netbsd*) gl_cv_func_printf_sizes_c99="guessing yes";; + # Guess yes on Android. + linux*-android*) gl_cv_func_printf_sizes_c99="guessing yes";; changequote([,])dnl # Guess yes on MSVC, no on mingw. mingw*) AC_EGREP_CPP([Known], [ @@ -132,17 +134,20 @@ int main () [gl_cv_func_printf_long_double=yes], [gl
Re: [PATCH] vasnprintf: Don't use %n on android
On Mon, Jan 21, 2019, at 5:11 PM, Tim Rühsen wrote: > On 1/21/19 5:00 PM, Hugo Beauzée-Luyssen wrote: > > On Mon, Jan 21, 2019, at 4:58 PM, Tim Rühsen wrote: > >> On 1/8/19 2:22 PM, Hugo Beauzée-Luyssen wrote: > >>> On Thu, Dec 20, 2018, at 2:53 AM, Bruno Haible wrote: > Hi, > > Hugo Beauzée-Luyssen wrote: > > 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject > > >>> org.videolan.vlc <<< > > 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), > > fault addr > > 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed > > on Android' > > Indeed, %n in *printf is not allowed on Android, see > https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp > https://android.googlesource.com/platform/bionic/+/master/docs/status.md > > > diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c > > index af3fcd1c7..e41d5f706 100644 > > --- a/lib/vasnprintf.c > > +++ b/lib/vasnprintf.c > > @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, > > # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) > > \ > > && !defined __UCLIBC__) > > \ > > || (defined __APPLE__ && defined __MACH__) > > \ > > -|| (defined _WIN32 && ! defined __CYGWIN__)) > > +|| (defined _WIN32 && ! defined __CYGWIN__) > > \ > > +|| defined __ANDROID__) > > fbp[1] = '%'; > > fbp[2] = 'n'; > > fbp[3] = '\0'; > > The patch looks good at first sight. But when you look at the comments a > couple of lines before it, you see that one can avoid %n only > if snprintf behaves well enough. To this effect, can you please report > the configure results (from a *native* Android compilation, not a cross- > compilation) of these tests: > > 1 = checking whether printf supports size specifiers as in C99... > 2 = checking whether printf supports 'long double' arguments... > 3 = checking whether printf supports infinite 'double' arguments... > 4 = checking whether printf supports infinite 'long double' arguments... > 5 = checking whether printf supports the 'a' and 'A' directives... > 6 = checking whether printf supports the 'F' directive... > 7 = checking whether printf supports the 'n' directive... > 8 = checking whether printf supports the 'ls' directive... > 9 = checking whether printf supports POSIX/XSI format strings with > positions... > 10 = checking whether printf supports the grouping flag... > 11 = checking whether printf supports the left-adjust flag correctly... > 12 = checking whether printf supports the zero flag correctly... > 13 = checking whether printf supports large precisions... > 14 = checking whether printf survives out-of-memory conditions... > 15 = checking for snprintf... > 16 = checking whether snprintf truncates the result as in C99... > 17 = checking whether snprintf returns a byte count as in C99... > 18 = checking whether snprintf fully supports the 'n' directive... > 19 = checking whether snprintf respects a size of 1... > 20 = checking whether vsnprintf respects a zero size as in C99... > > You should find these in the configure output of any package that > uses gnulib's 'vasnprintf' module. If you don't have one at hand, > create one using > ./gnulib-tool --create-testdir --dir=testdir --single-configure > vasnprintf > > Thanks. > > Bruno > > >>> > >>> Hi, > >>> > >>> I'm probably missing something, but for me this only seems to test for > >>> snprintf/printf/vasnprintf availability (including running configure in > >>> the generated test directory) > >> > >> I would really like to see the patch in gnulib as soon as possible. > >> > >> @hugo If it's not too much hassle, could you please provide the > >> requested information ? > >> > >> Regards, Tim > >> > > > > Hi, > > > > I'd love to, but I failed to fetch those so far. The provided command line > > didn't return any valuable information, and simply tested for the presence > > of various printf family function. > > > > Regards, > > So you cd'ed into testdir and run `./configure` !? > Yes > I also don't see much here (Debian unstable): > > $ grep -A1 -i 'checking.*printf' config.log > configure:6305: checking for vasnprintf > configure:6305: result: no > configure:6305: checking for snprintf > configure:6305: result: yes > -- > configure:8450: checking whether snprintf returns a byte count as in C99 > configure:8548: result: yes > configure:8559: checking for snprintf > configure:8559: result: yes > -- > configure:8568: checking whether
Re: [PATCH] vasnprintf: Don't use %n on android
On 1/21/19 5:00 PM, Hugo Beauzée-Luyssen wrote: > On Mon, Jan 21, 2019, at 4:58 PM, Tim Rühsen wrote: >> On 1/8/19 2:22 PM, Hugo Beauzée-Luyssen wrote: >>> On Thu, Dec 20, 2018, at 2:53 AM, Bruno Haible wrote: Hi, Hugo Beauzée-Luyssen wrote: > 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject > >>> org.videolan.vlc <<< > 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), > fault addr > 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on > Android' Indeed, %n in *printf is not allowed on Android, see https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp https://android.googlesource.com/platform/bionic/+/master/docs/status.md > diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c > index af3fcd1c7..e41d5f706 100644 > --- a/lib/vasnprintf.c > +++ b/lib/vasnprintf.c > @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, > # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) >\ > && !defined __UCLIBC__) >\ > || (defined __APPLE__ && defined __MACH__) >\ > -|| (defined _WIN32 && ! defined __CYGWIN__)) > +|| (defined _WIN32 && ! defined __CYGWIN__) >\ > +|| defined __ANDROID__) > fbp[1] = '%'; > fbp[2] = 'n'; > fbp[3] = '\0'; The patch looks good at first sight. But when you look at the comments a couple of lines before it, you see that one can avoid %n only if snprintf behaves well enough. To this effect, can you please report the configure results (from a *native* Android compilation, not a cross- compilation) of these tests: 1 = checking whether printf supports size specifiers as in C99... 2 = checking whether printf supports 'long double' arguments... 3 = checking whether printf supports infinite 'double' arguments... 4 = checking whether printf supports infinite 'long double' arguments... 5 = checking whether printf supports the 'a' and 'A' directives... 6 = checking whether printf supports the 'F' directive... 7 = checking whether printf supports the 'n' directive... 8 = checking whether printf supports the 'ls' directive... 9 = checking whether printf supports POSIX/XSI format strings with positions... 10 = checking whether printf supports the grouping flag... 11 = checking whether printf supports the left-adjust flag correctly... 12 = checking whether printf supports the zero flag correctly... 13 = checking whether printf supports large precisions... 14 = checking whether printf survives out-of-memory conditions... 15 = checking for snprintf... 16 = checking whether snprintf truncates the result as in C99... 17 = checking whether snprintf returns a byte count as in C99... 18 = checking whether snprintf fully supports the 'n' directive... 19 = checking whether snprintf respects a size of 1... 20 = checking whether vsnprintf respects a zero size as in C99... You should find these in the configure output of any package that uses gnulib's 'vasnprintf' module. If you don't have one at hand, create one using ./gnulib-tool --create-testdir --dir=testdir --single-configure vasnprintf Thanks. Bruno >>> >>> Hi, >>> >>> I'm probably missing something, but for me this only seems to test for >>> snprintf/printf/vasnprintf availability (including running configure in the >>> generated test directory) >> >> I would really like to see the patch in gnulib as soon as possible. >> >> @hugo If it's not too much hassle, could you please provide the >> requested information ? >> >> Regards, Tim >> > > Hi, > > I'd love to, but I failed to fetch those so far. The provided command line > didn't return any valuable information, and simply tested for the presence of > various printf family function. > > Regards, So you cd'ed into testdir and run `./configure` !? I also don't see much here (Debian unstable): $ grep -A1 -i 'checking.*printf' config.log configure:6305: checking for vasnprintf configure:6305: result: no configure:6305: checking for snprintf configure:6305: result: yes -- configure:8450: checking whether snprintf returns a byte count as in C99 configure:8548: result: yes configure:8559: checking for snprintf configure:8559: result: yes -- configure:8568: checking whether _snprintf is declared configure:8568: result: no What does that grep look for you ? @Bruno Is there something missing ? Regards, Tim signature.asc Description: OpenPGP digital signature
Re: [PATCH] vasnprintf: Don't use %n on android
On Mon, Jan 21, 2019, at 4:58 PM, Tim Rühsen wrote: > On 1/8/19 2:22 PM, Hugo Beauzée-Luyssen wrote: > > On Thu, Dec 20, 2018, at 2:53 AM, Bruno Haible wrote: > >> Hi, > >> > >> Hugo Beauzée-Luyssen wrote: > >>> 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject > >>> >>> org.videolan.vlc <<< > >>> 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), > >>> fault addr > >>> 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on > >>> Android' > >> > >> Indeed, %n in *printf is not allowed on Android, see > >> https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp > >> https://android.googlesource.com/platform/bionic/+/master/docs/status.md > >> > >>> diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c > >>> index af3fcd1c7..e41d5f706 100644 > >>> --- a/lib/vasnprintf.c > >>> +++ b/lib/vasnprintf.c > >>> @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, > >>> # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) > >>>\ > >>> && !defined __UCLIBC__) > >>>\ > >>> || (defined __APPLE__ && defined __MACH__) > >>>\ > >>> -|| (defined _WIN32 && ! defined __CYGWIN__)) > >>> +|| (defined _WIN32 && ! defined __CYGWIN__) > >>>\ > >>> +|| defined __ANDROID__) > >>> fbp[1] = '%'; > >>> fbp[2] = 'n'; > >>> fbp[3] = '\0'; > >> > >> The patch looks good at first sight. But when you look at the comments a > >> couple of lines before it, you see that one can avoid %n only > >> if snprintf behaves well enough. To this effect, can you please report > >> the configure results (from a *native* Android compilation, not a cross- > >> compilation) of these tests: > >> > >> 1 = checking whether printf supports size specifiers as in C99... > >> 2 = checking whether printf supports 'long double' arguments... > >> 3 = checking whether printf supports infinite 'double' arguments... > >> 4 = checking whether printf supports infinite 'long double' arguments... > >> 5 = checking whether printf supports the 'a' and 'A' directives... > >> 6 = checking whether printf supports the 'F' directive... > >> 7 = checking whether printf supports the 'n' directive... > >> 8 = checking whether printf supports the 'ls' directive... > >> 9 = checking whether printf supports POSIX/XSI format strings with > >> positions... > >> 10 = checking whether printf supports the grouping flag... > >> 11 = checking whether printf supports the left-adjust flag correctly... > >> 12 = checking whether printf supports the zero flag correctly... > >> 13 = checking whether printf supports large precisions... > >> 14 = checking whether printf survives out-of-memory conditions... > >> 15 = checking for snprintf... > >> 16 = checking whether snprintf truncates the result as in C99... > >> 17 = checking whether snprintf returns a byte count as in C99... > >> 18 = checking whether snprintf fully supports the 'n' directive... > >> 19 = checking whether snprintf respects a size of 1... > >> 20 = checking whether vsnprintf respects a zero size as in C99... > >> > >> You should find these in the configure output of any package that > >> uses gnulib's 'vasnprintf' module. If you don't have one at hand, > >> create one using > >> ./gnulib-tool --create-testdir --dir=testdir --single-configure > >> vasnprintf > >> > >> Thanks. > >> > >> Bruno > >> > > > > Hi, > > > > I'm probably missing something, but for me this only seems to test for > > snprintf/printf/vasnprintf availability (including running configure in the > > generated test directory) > > I would really like to see the patch in gnulib as soon as possible. > > @hugo If it's not too much hassle, could you please provide the > requested information ? > > Regards, Tim > Hi, I'd love to, but I failed to fetch those so far. The provided command line didn't return any valuable information, and simply tested for the presence of various printf family function. Regards, -- Hugo Beauzée-Luyssen h...@beauzee.fr
Re: [PATCH] vasnprintf: Don't use %n on android
On 1/8/19 2:22 PM, Hugo Beauzée-Luyssen wrote: > On Thu, Dec 20, 2018, at 2:53 AM, Bruno Haible wrote: >> Hi, >> >> Hugo Beauzée-Luyssen wrote: >>> 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject >>> >>> org.videolan.vlc <<< >>> 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), >>> fault addr >>> 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on >>> Android' >> >> Indeed, %n in *printf is not allowed on Android, see >> https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp >> https://android.googlesource.com/platform/bionic/+/master/docs/status.md >> >>> diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c >>> index af3fcd1c7..e41d5f706 100644 >>> --- a/lib/vasnprintf.c >>> +++ b/lib/vasnprintf.c >>> @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, >>> # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) >>> \ >>> && !defined __UCLIBC__) >>> \ >>> || (defined __APPLE__ && defined __MACH__) >>> \ >>> -|| (defined _WIN32 && ! defined __CYGWIN__)) >>> +|| (defined _WIN32 && ! defined __CYGWIN__) >>> \ >>> +|| defined __ANDROID__) >>> fbp[1] = '%'; >>> fbp[2] = 'n'; >>> fbp[3] = '\0'; >> >> The patch looks good at first sight. But when you look at the comments a >> couple of lines before it, you see that one can avoid %n only >> if snprintf behaves well enough. To this effect, can you please report >> the configure results (from a *native* Android compilation, not a cross- >> compilation) of these tests: >> >> 1 = checking whether printf supports size specifiers as in C99... >> 2 = checking whether printf supports 'long double' arguments... >> 3 = checking whether printf supports infinite 'double' arguments... >> 4 = checking whether printf supports infinite 'long double' arguments... >> 5 = checking whether printf supports the 'a' and 'A' directives... >> 6 = checking whether printf supports the 'F' directive... >> 7 = checking whether printf supports the 'n' directive... >> 8 = checking whether printf supports the 'ls' directive... >> 9 = checking whether printf supports POSIX/XSI format strings with >> positions... >> 10 = checking whether printf supports the grouping flag... >> 11 = checking whether printf supports the left-adjust flag correctly... >> 12 = checking whether printf supports the zero flag correctly... >> 13 = checking whether printf supports large precisions... >> 14 = checking whether printf survives out-of-memory conditions... >> 15 = checking for snprintf... >> 16 = checking whether snprintf truncates the result as in C99... >> 17 = checking whether snprintf returns a byte count as in C99... >> 18 = checking whether snprintf fully supports the 'n' directive... >> 19 = checking whether snprintf respects a size of 1... >> 20 = checking whether vsnprintf respects a zero size as in C99... >> >> You should find these in the configure output of any package that >> uses gnulib's 'vasnprintf' module. If you don't have one at hand, >> create one using >> ./gnulib-tool --create-testdir --dir=testdir --single-configure vasnprintf >> >> Thanks. >> >> Bruno >> > > Hi, > > I'm probably missing something, but for me this only seems to test for > snprintf/printf/vasnprintf availability (including running configure in the > generated test directory) I would really like to see the patch in gnulib as soon as possible. @hugo If it's not too much hassle, could you please provide the requested information ? Regards, Tim signature.asc Description: OpenPGP digital signature
Re: [PATCH] vasnprintf: Don't use %n on android
On Thu, Dec 20, 2018, at 2:53 AM, Bruno Haible wrote: > Hi, > > Hugo Beauzée-Luyssen wrote: > > 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject >>> > > org.videolan.vlc <<< > > 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), > > fault addr > > 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on > > Android' > > Indeed, %n in *printf is not allowed on Android, see > https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp > https://android.googlesource.com/platform/bionic/+/master/docs/status.md > > > diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c > > index af3fcd1c7..e41d5f706 100644 > > --- a/lib/vasnprintf.c > > +++ b/lib/vasnprintf.c > > @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, > > # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) > > \ > > && !defined __UCLIBC__) > > \ > > || (defined __APPLE__ && defined __MACH__) > > \ > > -|| (defined _WIN32 && ! defined __CYGWIN__)) > > +|| (defined _WIN32 && ! defined __CYGWIN__) > > \ > > +|| defined __ANDROID__) > > fbp[1] = '%'; > > fbp[2] = 'n'; > > fbp[3] = '\0'; > > The patch looks good at first sight. But when you look at the comments a > couple of lines before it, you see that one can avoid %n only > if snprintf behaves well enough. To this effect, can you please report > the configure results (from a *native* Android compilation, not a cross- > compilation) of these tests: > > 1 = checking whether printf supports size specifiers as in C99... > 2 = checking whether printf supports 'long double' arguments... > 3 = checking whether printf supports infinite 'double' arguments... > 4 = checking whether printf supports infinite 'long double' arguments... > 5 = checking whether printf supports the 'a' and 'A' directives... > 6 = checking whether printf supports the 'F' directive... > 7 = checking whether printf supports the 'n' directive... > 8 = checking whether printf supports the 'ls' directive... > 9 = checking whether printf supports POSIX/XSI format strings with > positions... > 10 = checking whether printf supports the grouping flag... > 11 = checking whether printf supports the left-adjust flag correctly... > 12 = checking whether printf supports the zero flag correctly... > 13 = checking whether printf supports large precisions... > 14 = checking whether printf survives out-of-memory conditions... > 15 = checking for snprintf... > 16 = checking whether snprintf truncates the result as in C99... > 17 = checking whether snprintf returns a byte count as in C99... > 18 = checking whether snprintf fully supports the 'n' directive... > 19 = checking whether snprintf respects a size of 1... > 20 = checking whether vsnprintf respects a zero size as in C99... > > You should find these in the configure output of any package that > uses gnulib's 'vasnprintf' module. If you don't have one at hand, > create one using > ./gnulib-tool --create-testdir --dir=testdir --single-configure vasnprintf > > Thanks. > > Bruno > Hi, I'm probably missing something, but for me this only seems to test for snprintf/printf/vasnprintf availability (including running configure in the generated test directory) Regards, -- Hugo Beauzée-Luyssen h...@beauzee.fr
Re: [PATCH] vasnprintf: Don't use %n on android
Hi, Hugo Beauzée-Luyssen wrote: > 12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject >>> > org.videolan.vlc <<< > 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault > addr > 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on > Android' Indeed, %n in *printf is not allowed on Android, see https://android.googlesource.com/platform/bionic/+/master/libc/stdio/vfprintf.cpp https://android.googlesource.com/platform/bionic/+/master/docs/status.md > diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c > index af3fcd1c7..e41d5f706 100644 > --- a/lib/vasnprintf.c > +++ b/lib/vasnprintf.c > @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, > # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3))\ > && !defined __UCLIBC__)\ > || (defined __APPLE__ && defined __MACH__) \ > -|| (defined _WIN32 && ! defined __CYGWIN__)) > +|| (defined _WIN32 && ! defined __CYGWIN__) \ > +|| defined __ANDROID__) > fbp[1] = '%'; > fbp[2] = 'n'; > fbp[3] = '\0'; The patch looks good at first sight. But when you look at the comments a couple of lines before it, you see that one can avoid %n only if snprintf behaves well enough. To this effect, can you please report the configure results (from a *native* Android compilation, not a cross- compilation) of these tests: 1 = checking whether printf supports size specifiers as in C99... 2 = checking whether printf supports 'long double' arguments... 3 = checking whether printf supports infinite 'double' arguments... 4 = checking whether printf supports infinite 'long double' arguments... 5 = checking whether printf supports the 'a' and 'A' directives... 6 = checking whether printf supports the 'F' directive... 7 = checking whether printf supports the 'n' directive... 8 = checking whether printf supports the 'ls' directive... 9 = checking whether printf supports POSIX/XSI format strings with positions... 10 = checking whether printf supports the grouping flag... 11 = checking whether printf supports the left-adjust flag correctly... 12 = checking whether printf supports the zero flag correctly... 13 = checking whether printf supports large precisions... 14 = checking whether printf survives out-of-memory conditions... 15 = checking for snprintf... 16 = checking whether snprintf truncates the result as in C99... 17 = checking whether snprintf returns a byte count as in C99... 18 = checking whether snprintf fully supports the 'n' directive... 19 = checking whether snprintf respects a size of 1... 20 = checking whether vsnprintf respects a zero size as in C99... You should find these in the configure output of any package that uses gnulib's 'vasnprintf' module. If you don't have one at hand, create one using ./gnulib-tool --create-testdir --dir=testdir --single-configure vasnprintf Thanks. Bruno
[PATCH] vasnprintf: Don't use %n on android
12-14 19:10:02.633 F DEBUG : pid: 31664, tid: 32389, name: VlcObject >>> org.videolan.vlc <<< 12-14 19:10:02.633 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr 12-14 19:10:02.633 F DEBUG : Abort message: 'FORTIFY: %n not allowed on Android' --- lib/vasnprintf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c index af3fcd1c7..e41d5f706 100644 --- a/lib/vasnprintf.c +++ b/lib/vasnprintf.c @@ -4874,7 +4874,8 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3))\ && !defined __UCLIBC__)\ || (defined __APPLE__ && defined __MACH__) \ -|| (defined _WIN32 && ! defined __CYGWIN__)) +|| (defined _WIN32 && ! defined __CYGWIN__) \ +|| defined __ANDROID__) fbp[1] = '%'; fbp[2] = 'n'; fbp[3] = '\0'; -- 2.19.2
