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| author | Gabriel Krisman Bertazi <krisman@collabora.com> | 2020-10-03 23:25:32 -0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-10-26 13:46:46 +0100 |
| commit | 2424b14605c71a7187c14edd525044eb36bdea47 (patch) | |
| tree | ba9a94d548fafade96dddbe8bf64c29ebd7f2332 | |
| parent | bc3d7bf61a9eaecccc84dc2ecc2a9a3fa4f5ec47 (diff) | |
| download | linux-2424b14605c71a7187c14edd525044eb36bdea47.tar.gz linux-2424b14605c71a7187c14edd525044eb36bdea47.tar.bz2 linux-2424b14605c71a7187c14edd525044eb36bdea47.zip | |
x86/elf: Use e_machine to select start_thread for x32
Since TIF_X32 is going away, avoid using it to find the ELF type in
compat_start_thread.
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 executing start_thread()
in compat mode.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20201004032536.1229030-7-krisman@collabora.com
| -rw-r--r-- | arch/x86/include/asm/elf.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 5 |
2 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 9220efc65d78..109697a19eb1 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -186,8 +186,9 @@ static inline void elf_common_init(struct thread_struct *t, #define COMPAT_ELF_PLAT_INIT(regs, load_addr) \ elf_common_init(¤t->thread, regs, __USER_DS) -void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp); -#define compat_start_thread compat_start_thread +void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32); +#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \ + compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64) void set_personality_ia32(bool); #define COMPAT_SET_PERSONALITY(ex) \ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index df342bedea88..5fb4103101f5 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -511,11 +511,10 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) EXPORT_SYMBOL_GPL(start_thread); #ifdef CONFIG_COMPAT -void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp) +void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32) { start_thread_common(regs, new_ip, new_sp, - test_thread_flag(TIF_X32) - ? __USER_CS : __USER32_CS, + x32 ? __USER_CS : __USER32_CS, __USER_DS, __USER_DS); } #endif |