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Commit 16930251 authored by Sami Tolvanen's avatar Sami Tolvanen
Browse files

ANDROID: x86: fix function types in COND_SYSCALL 



Define a weak function for COND_SYSCALL instead of creating a weak
alias to a function with an incompatible type. This fixes indirect
call mismatches with Control-Flow Integrity.

Bug: 138254717
Change-Id: I3effbbf5c86107103cf29a40dfb37b268e59bfd8
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
parent 9a8a0e6f

arch/x86/include/asm/syscall_wrapper.h

+16 −5
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#ifndef _ASM_X86_SYSCALL_WRAPPER_H

#define _ASM_X86_SYSCALL_WRAPPER_H



struct pt_regs;



/* Mapping of registers to parameters for syscalls on x86-64 and x32 */

#define SC_X86_64_REGS_TO_ARGS(x, ...)					\

	__MAP(x,__SC_ARGS						\
@@ -57,8 +59,14 @@ 
	asmlinkage long __x64_sys_##sname(const struct pt_regs *__unused)



#define COND_SYSCALL(name)							\

	cond_syscall(__x64_sys_##name);					\

	cond_syscall(__ia32_sys_##name)

	asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused)	\

	{									\

		return sys_ni_syscall();					\

	}									\

	asmlinkage __weak long __ia32_sys_##name(const struct pt_regs *__unused)\

	{									\

		return sys_ni_syscall();					\

	}



#define SYS_NI(name)							\

	SYSCALL_ALIAS(__x64_sys_##name, sys_ni_posix_timers);		\
@@ -190,7 +198,11 @@ 
#endif



#ifndef COND_SYSCALL

#define COND_SYSCALL(name) cond_syscall(__x64_sys_##name)

#define COND_SYSCALL(name) 							\

	asmlinkage __weak long __x64_sys_##name(const struct pt_regs *__unused)	\

	{									\

		return sys_ni_syscall();					\

	}

#endif



#ifndef SYS_NI
@@ -202,7 +214,6 @@ 
 * For VSYSCALLS, we need to declare these three syscalls with the new

 * pt_regs-based calling convention for in-kernel use.

 */

struct pt_regs;

asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs);

asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs);

asmlinkage long __x64_sys_time(const struct pt_regs *regs);