Messages in this thread Patch in this message |  | | Date | Thu, 5 Apr 2018 22:31:21 +0200 | From | Dominik Brodowski <> | Subject | Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64 |
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On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote: > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build: > > make[2]: *** No rule to make target 'archheaders'. Stop. > arch/um/Makefile:119: recipe for target 'archheaders' failed > make[1]: *** [archheaders] Error 2 > make[1]: *** Waiting for unfinished jobs....
Ah, that's caused by patch 8/8 which I did and do not like all that much anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like __sys_x86_pread64, but expects the generic syscall stub sys_pread64 referenced there. Fixup patch below; could be folded with patch 8/8. Or patch 8/8 could simply be dropped from the series altogether...
Thanks, Dominik
-------------------------------------------------------------------------- From f5049ea4e1e5e7751e72a22cbc1b3a9389959a04 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski <linux@dominikbrodowski.net> Date: Thu, 5 Apr 2018 22:16:23 +0200 Subject: [PATCH] syscalls/x86: fix UML syscall table
To differentiate the different calling regime used on x86, the syscall functions received __sys_x86_ as prefix (instead of sys_). This breaks the build of UML on 64-bit x86, as it re-uses the same syscall table.
To fix this, replace the __sys_x86_ prefix with sys_ during the generation of <asm/syscalls_64.h>.
Fixes: syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*() Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: x86@kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh index d71ef4bd3615..d6376b87ecb2 100644 --- a/arch/x86/entry/syscalls/syscalltbl.sh +++ b/arch/x86/entry/syscalls/syscalltbl.sh @@ -20,17 +20,47 @@ syscall_macro() { echo "__SYSCALL_${abi}($nr, $real_entry, $qualifier)" } -emit() { +emit64() { abi="$1" nr="$2" entry="$3" compat="$4" - if [ "$abi" = "64" -a -n "$compat" ]; then + if [ "$abi" = "I386" ]; then + echo "emit64() called for a 32-bit syscall" >&2 + exit 1 + fi + + if [ -n "$compat" ]; then echo "a compat entry for a 64-bit syscall makes no sense" >&2 exit 1 fi + if [ -n "$entry" ]; then + # For CONFIG_UML, we need to strip the __sys_x86 prefix + if [ "${entry}" = "${entry#__compat_sys}" ]; then + umlentry="sys${entry#__sys_x86}" + fi + + echo "#ifdef CONFIG_X86" + syscall_macro "$abi" "$nr" "$entry" + echo "#else /* CONFIG_UML */" + syscall_macro "$abi" "$nr" "$umlentry" + echo "#endif" + fi +} + +emit32() { + abi="$1" + nr="$2" + entry="$3" + compat="$4" + + if [ "$abi" = "64" ]; then + echo "emit32() called for a 64-bit syscall" >&2 + exit 1 + fi + if [ -z "$compat" ]; then if [ -n "$entry" ]; then syscall_macro "$abi" "$nr" "$entry" @@ -53,14 +83,14 @@ grep '^[0-9]' "$in" | sort -n | ( # COMMON is the same as 64, except that we don't expect X32 # programs to use it. Our expectation has nothing to do with # any generated code, so treat them the same. - emit 64 "$nr" "$entry" "$compat" + emit64 64 "$nr" "$entry" "$compat" elif [ "$abi" = "X32" ]; then # X32 is equivalent to 64 on an X32-compatible kernel. echo "#ifdef CONFIG_X86_X32_ABI" - emit 64 "$nr" "$entry" "$compat" + emit64 64 "$nr" "$entry" "$compat" echo "#endif" elif [ "$abi" = "I386" ]; then - emit "$abi" "$nr" "$entry" "$compat" + emit32 "$abi" "$nr" "$entry" "$compat" else echo "Unknown abi $abi" >&2 exit 1
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