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From: Florian Weimer <fw@sourceware.org>
To: glibc-cvs@sourceware.org
Subject: [glibc] arm: Guard ucontext _rtld_global_ro access by SHARED, not PIC macro
Date: Fri, 17 Dec 2021 10:49:09 +0000 (GMT) [thread overview]
Message-ID: <20211217104909.08A0B3858410@sourceware.org> (raw)
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ce1e5b11229f19820b86f8b19d651f16009552b0
commit ce1e5b11229f19820b86f8b19d651f16009552b0
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Dec 17 11:48:41 2021 +0100
arm: Guard ucontext _rtld_global_ro access by SHARED, not PIC macro
Due to PIE-by-default, PIC is now defined in more cases. libc.a
does not have _rtld_global_ro, and statically linking setcontext
fails. SHARED is the right condition to use, so that libc.a
references _dl_hwcap instead of _rtld_global_ro.
For static PIE support, the !SHARED case would still have to be made
PIC. This patch does not achieve that.
Fixes commit 23645707f12f2dd9d80b51effb2d9618a7b65565
("Replace --enable-static-pie with --disable-default-pie").
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Diff:
---
sysdeps/unix/sysv/linux/arm/getcontext.S | 4 ++--
sysdeps/unix/sysv/linux/arm/setcontext.S | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/arm/getcontext.S b/sysdeps/unix/sysv/linux/arm/getcontext.S
index 3aa581c4da..11bfcbe5f5 100644
--- a/sysdeps/unix/sysv/linux/arm/getcontext.S
+++ b/sysdeps/unix/sysv/linux/arm/getcontext.S
@@ -50,7 +50,7 @@ ENTRY(__getcontext)
/* Store FP regs. Much of the FP code is copied from arm/setjmp.S. */
-#ifdef PIC
+#ifdef SHARED
ldr r2, 1f
ldr r1, .Lrtld_global_ro
0: add r2, pc, r2
@@ -102,7 +102,7 @@ ENTRY(__getcontext)
END(__getcontext)
-#ifdef PIC
+#ifdef SHARED
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
.Lrtld_global_ro:
.long C_SYMBOL_NAME(_rtld_global_ro)(GOT)
diff --git a/sysdeps/unix/sysv/linux/arm/setcontext.S b/sysdeps/unix/sysv/linux/arm/setcontext.S
index 8be8beefea..4c7c6e5509 100644
--- a/sysdeps/unix/sysv/linux/arm/setcontext.S
+++ b/sysdeps/unix/sysv/linux/arm/setcontext.S
@@ -32,7 +32,7 @@ ENTRY(__setcontext)
add r0, r0, #UCONTEXT_REGSPACE
/* Restore the VFP registers. Copied from arm/__longjmp.S. */
-#ifdef PIC
+#ifdef SHARED
ldr r2, 1f
ldr r1, .Lrtld_global_ro
0: add r2, pc, r2
@@ -101,7 +101,7 @@ ENTRY(__startcontext)
.fnend
END(__startcontext)
-#ifdef PIC
+#ifdef SHARED
1: .long _GLOBAL_OFFSET_TABLE_ - 0b - PC_OFS
.Lrtld_global_ro:
.long C_SYMBOL_NAME(_rtld_global_ro)(GOT)
reply other threads:[~2021-12-17 10:49 UTC|newest]
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