forked from Minki/linux
b485342bd7
Commita074335a37("x86, um: Mark system call tables readonly") was supposed to mark the sys_call_table in UML as RO by adding the const, but it doesn't have the desired effect as it's nevertheless being placed into the data section since __cacheline_aligned enforces sys_call_table being placed into .data..cacheline_aligned instead. We need to use the ____cacheline_aligned version instead to fix this issue. Before: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 D sys_call_table 0000000000000000 D syscall_table_size After: $ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table" U sys_writev 0000000000000000 R sys_call_table 0000000000000000 D syscall_table_size Fixes:a074335a37("x86, um: Mark system call tables readonly") Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Richard Weinberger <richard@nod.at>
60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
/*
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* System call table for UML/x86-64, copied from arch/x86/kernel/syscall_*.c
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* with some changes for UML.
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*/
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#include <linux/linkage.h>
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#include <linux/sys.h>
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#include <linux/cache.h>
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#include <generated/user_constants.h>
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#define __NO_STUBS
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/*
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* Below you can see, in terms of #define's, the differences between the x86-64
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* and the UML syscall table.
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*/
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/* Not going to be implemented by UML, since we have no hardware. */
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#define stub_iopl sys_ni_syscall
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#define sys_ioperm sys_ni_syscall
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/*
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* The UML TLS problem. Note that x86_64 does not implement this, so the below
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* is needed only for the ia32 compatibility.
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*/
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/* On UML we call it this way ("old" means it's not mmap2) */
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#define sys_mmap old_mmap
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#define stub_clone sys_clone
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#define stub_fork sys_fork
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#define stub_vfork sys_vfork
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#define stub_execve sys_execve
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#define stub_execveat sys_execveat
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#define stub_rt_sigreturn sys_rt_sigreturn
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#define __SYSCALL_COMMON(nr, sym, compat) __SYSCALL_64(nr, sym, compat)
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#define __SYSCALL_X32(nr, sym, compat) /* Not supported */
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#define __SYSCALL_64(nr, sym, compat) extern asmlinkage void sym(void) ;
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#include <asm/syscalls_64.h>
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#undef __SYSCALL_64
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#define __SYSCALL_64(nr, sym, compat) [ nr ] = sym,
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typedef void (*sys_call_ptr_t)(void);
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extern void sys_ni_syscall(void);
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const sys_call_ptr_t sys_call_table[] ____cacheline_aligned = {
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/*
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* Smells like a compiler bug -- it doesn't work
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* when the & below is removed.
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*/
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[0 ... __NR_syscall_max] = &sys_ni_syscall,
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#include <asm/syscalls_64.h>
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};
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int syscall_table_size = sizeof(sys_call_table);
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