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From: Gabriel Krisman Bertazi <krisman@collabora.com>
To: luto@kernel.org, tglx@linutronix.de
Cc: hpa@zytor.com, bp@alien8.de, rric@kernel.org,
	peterz@infradead.org, mingo@redhat.com, x86@kernel.org,
	linux-kernel@vger.kernel.org,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	kernel@collabora.com
Subject: [PATCH 4/6] x86: elf: Use e_machine to choose DLINFO in compat
Date: Sat, 12 Sep 2020 03:05:51 -0400	[thread overview]
Message-ID: <20200912070553.330622-5-krisman@collabora.com> (raw)
In-Reply-To: <20200912070553.330622-1-krisman@collabora.com>

Since TIF_X32 is going away, avoid using it to find the ELF type on
ARCH_DLINFO.

According to SysV AMD64 ABI Draft, an AMD64 ELF object using ILP32 must
have ELFCLASS32 with (E_MACHINE == EM_X86_64), so use that ELF field to
differentiate a x32 object from a IA32 object when loading ARCH_DLINFO
in compat mode.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 arch/x86/include/asm/elf.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index b9a5d488f1a5..9220efc65d78 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -361,7 +361,7 @@ do {									\
 #define AT_SYSINFO		32
 
 #define COMPAT_ARCH_DLINFO						\
-if (test_thread_flag(TIF_X32))						\
+if (exec->e_machine == EM_X86_64)					\
 	ARCH_DLINFO_X32;						\
 else									\
 	ARCH_DLINFO_IA32
-- 
2.28.0


  parent reply	other threads:[~2020-09-12  7:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-12  7:05 [PATCH 0/6] Prepare for removal of TIF_IA32 and TIF_X32 Gabriel Krisman Bertazi
2020-09-12  7:05 ` [PATCH 1/6] x86: events: Avoid TIF_IA32 when checking 64bit mode Gabriel Krisman Bertazi
2020-09-14 10:33   ` peterz
2020-09-12  7:05 ` [PATCH 2/6] x86: Simplify compat syscall userspace allocation Gabriel Krisman Bertazi
2020-09-12  7:08   ` Christoph Hellwig
2020-09-12  7:54     ` Gabriel Krisman Bertazi
2020-09-12  7:05 ` [PATCH 3/6] x86: oprofile: Avoid TIF_IA32 when checking 64bit mode Gabriel Krisman Bertazi
2020-09-12  7:05 ` Gabriel Krisman Bertazi [this message]
2020-09-12  7:05 ` [PATCH 5/6] x86: elf: Use e_machine to select start_thread for x32 Gabriel Krisman Bertazi
2020-09-12  7:05 ` [PATCH 6/6] x86: elf: Use e_machine to select setup_additional_pages " Gabriel Krisman Bertazi

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