From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7814) id 77CF33858027; Mon, 15 Nov 2021 22:40:22 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 77CF33858027 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Fangrui Song To: glibc-cvs@sourceware.org Subject: [glibc/google/grte/v5-2.27/master] Use libc_hidden_* for fputs (bug 15105). X-Act-Checkin: glibc X-Git-Author: Joseph Myers X-Git-Refname: refs/heads/google/grte/v5-2.27/master X-Git-Oldrev: 9c29d1a12316038c4586334e6d5e7a9cef12b25e X-Git-Newrev: b8365ac9056e572ef9cbf1e40a2691b7e06f1f2e Message-Id: <20211115224022.77CF33858027@sourceware.org> Date: Mon, 15 Nov 2021 22:40:22 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Nov 2021 22:40:22 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b8365ac9056e572ef9cbf1e40a2691b7e06f1f2e commit b8365ac9056e572ef9cbf1e40a2691b7e06f1f2e Author: Joseph Myers Date: Thu Feb 15 20:58:16 2018 +0000 Use libc_hidden_* for fputs (bug 15105). Among other localplt test failures when building with -Os, there are libc.so PLT references for fputs. fputs calls normally get redirected to _IO_fputs by a macro in include/stdio.h (and _IO_fputs in turn uses libc_hidden_proto), but GCC can convert an fprintf call with a constant string argument into an fputs call, which of course is then unaffected by the macro redirection. (I don't know why this issue only appears with -Os.) This patch duly adds a use of libc_hidden_proto for fputs. I see no obvious reason why the fputs macro redirection is needed at all, but this patch does not change it. Tested for x86_64 (both that it removes this particular localplt failure for -Os - but other such failures remain so the bug can't yet be closed - and that the testsuite continues to pass without -Os). [BZ #15105] * include/stdio.h [!_ISOMAC && IS_IN (libc)] (fputs): Use libc_hidden_proto. * libio/iofputs.c (fputs): Use libc_hidden_weak. (cherry picked from commit 499b315324519f8deb5b42a143a76319934a3ab0) Diff: --- include/stdio.h | 4 ++++ libio/iofputs.c | 1 + 2 files changed, 5 insertions(+) diff --git a/include/stdio.h b/include/stdio.h index 602434509f..820ba5491f 100644 --- a/include/stdio.h +++ b/include/stdio.h @@ -135,6 +135,10 @@ extern int _IO_new_fclose (_IO_FILE*); # define fclose(fp) _IO_new_fclose (fp) extern int _IO_fputs (const char*, _IO_FILE*); libc_hidden_proto (_IO_fputs) +/* The compiler may optimize calls to fprintf into calls to fputs. + Use libc_hidden_proto to ensure that those calls, not redirected by + the fputs macro, also do not go through the PLT. */ +libc_hidden_proto (fputs) # define fputs(str, fp) _IO_fputs (str, fp) extern int _IO_new_fsetpos (_IO_FILE *, const _IO_fpos_t *); # define fsetpos(fp, posp) _IO_new_fsetpos (fp, posp) diff --git a/libio/iofputs.c b/libio/iofputs.c index b4fbeb5e60..176e9ed281 100644 --- a/libio/iofputs.c +++ b/libio/iofputs.c @@ -43,6 +43,7 @@ _IO_fputs (const char *str, _IO_FILE *fp) libc_hidden_def (_IO_fputs) weak_alias (_IO_fputs, fputs) +libc_hidden_weak (fputs) # ifndef _IO_MTSAFE_IO strong_alias (_IO_fputs, __fputs_unlocked)