mirror of
				git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
				synced 2025-11-01 09:13:37 +00:00 
			
		
		
		
	The direct-call syscall dispatch function doesn't know that the exit()
and exit_group() syscall handlers don't return, so the call sites aren't
optimized accordingly.
Fix that by marking the exit syscall declarations __noreturn.
Fixes the following warnings:
  vmlinux.o: warning: objtool: x64_sys_call+0x2804: __x64_sys_exit() is missing a __noreturn annotation
  vmlinux.o: warning: objtool: ia32_sys_call+0x29b6: __ia32_sys_exit_group() is missing a __noreturn annotation
Fixes: 1e3ad78334 ("x86/syscall: Don't force use of indirect calls for system calls")
Closes: https://lkml.kernel.org/lkml/6dba9b32-db2c-4e6d-9500-7a08852f17a3@paulmck-laptop
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/5d8882bc077d8eadcc7fd1740b56dfb781f12288.1719381528.git.jpoimboe@kernel.org
		
	
			
		
			
				
	
	
		
			92 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
			
		
		
	
	
			92 lines
		
	
	
	
		
			1.8 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable file
		
	
	
	
	
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0-only
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#
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# Generate a syscall table header.
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#
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# Each line of the syscall table should have the following format:
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#
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# NR ABI NAME [NATIVE] [COMPAT]
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#
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# NR       syscall number
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# ABI      ABI name
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# NAME     syscall name
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# NATIVE   native entry point (optional)
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# COMPAT   compat entry point (optional)
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set -e
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usage() {
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	echo >&2 "usage: $0 [--abis ABIS] INFILE OUTFILE" >&2
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	echo >&2
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	echo >&2 "  INFILE    input syscall table"
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	echo >&2 "  OUTFILE   output header file"
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	echo >&2
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	echo >&2 "options:"
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	echo >&2 "  --abis ABIS        ABI(s) to handle (By default, all lines are handled)"
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	exit 1
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}
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# default unless specified by options
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abis=
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while [ $# -gt 0 ]
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do
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	case $1 in
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	--abis)
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		abis=$(echo "($2)" | tr ',' '|')
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		shift 2;;
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	-*)
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		echo "$1: unknown option" >&2
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		usage;;
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	*)
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		break;;
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	esac
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done
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if [ $# -ne 2 ]; then
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	usage
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fi
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infile="$1"
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outfile="$2"
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nxt=0
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grep -E "^[0-9]+[[:space:]]+$abis" "$infile" | {
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	while read nr abi name native compat noreturn; do
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		if [ $nxt -gt $nr ]; then
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			echo "error: $infile: syscall table is not sorted or duplicates the same syscall number" >&2
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			exit 1
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		fi
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		while [ $nxt -lt $nr ]; do
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			echo "__SYSCALL($nxt, sys_ni_syscall)"
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			nxt=$((nxt + 1))
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		done
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		if [ "$compat" = "-" ]; then
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			unset compat
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		fi
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		if [ -n "$noreturn" ]; then
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			if [ "$noreturn" != "noreturn" ]; then
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				echo "error: $infile: invalid string \"$noreturn\" in 'noreturn' column"
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				exit 1
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			fi
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			if [ -n "$compat" ]; then
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				echo "__SYSCALL_COMPAT_NORETURN($nr, $native, $compat)"
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			else
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				echo "__SYSCALL_NORETURN($nr, $native)"
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			fi
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		elif [ -n "$compat" ]; then
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			echo "__SYSCALL_WITH_COMPAT($nr, $native, $compat)"
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		elif [ -n "$native" ]; then
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			echo "__SYSCALL($nr, $native)"
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		else
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			echo "__SYSCALL($nr, sys_ni_syscall)"
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		fi
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		nxt=$((nr + 1))
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	done
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} > "$outfile"
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