From 499b5d176a77773cab5479264a3d5067176df21c Mon Sep 17 00:00:00 2001 From: Timothy E Baldwin Date: Thu, 12 May 2016 18:47:29 +0100 Subject: [PATCH] linux-user: Renumber TARGET_QEMU_ESIGRETURN, make it not arch-specific Currently we define a QEMU-internal errno TARGET_QEMU_ESIGRETURN only on the MIPS and PPC targets; move this to errno_defs.h so it is available for all architectures, and renumber it to 513. We pick 513 because this is safe from future use as a system call return value: Linux uses it as ERESTART_NOINTR internally and never allows that errno to escape to userspace. Signed-off-by: Timothy Edward Baldwin Message-id: 1441497448-32489-4-git-send-email-T.E.Baldwin99@members.leeds.ac.uk [PMM: TARGET_ERESTARTSYS split out into preceding patch, add comment] Reviewed-by: Peter Maydell Reviewed-by: Laurent Vivier Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/errno_defs.h | 9 +++++++++ linux-user/mips/target_syscall.h | 4 ---- linux-user/mips64/target_syscall.h | 4 ---- linux-user/ppc/target_syscall.h | 2 -- 4 files changed, 9 insertions(+), 10 deletions(-) diff --git a/linux-user/errno_defs.h b/linux-user/errno_defs.h index b7a8c9ff95..65522c4516 100644 --- a/linux-user/errno_defs.h +++ b/linux-user/errno_defs.h @@ -147,3 +147,12 @@ * kernel uses for the same purpose. */ #define TARGET_ERESTARTSYS 512 /* Restart system call (if SA_RESTART) */ + +/* QEMU internal, not visible to the guest. This is returned by the + * do_sigreturn() code after a successful sigreturn syscall, to indicate + * that it has correctly set the guest registers and so the main loop + * should not touch them. We use the value the guest would use for + * ERESTART_NOINTR (which is kernel internal) to guarantee that we won't + * clash with a valid guest errno now or in the future. + */ +#define TARGET_QEMU_ESIGRETURN 513 /* Return from signal */ diff --git a/linux-user/mips/target_syscall.h b/linux-user/mips/target_syscall.h index 68db160e53..e8e305cc9c 100644 --- a/linux-user/mips/target_syscall.h +++ b/linux-user/mips/target_syscall.h @@ -222,10 +222,6 @@ struct target_pt_regs { #define TARGET_ENOTRECOVERABLE 166 /* State not recoverable */ - -/* Nasty hack: define a fake errno value for use by sigreturn. */ -#define TARGET_QEMU_ESIGRETURN 255 - #define UNAME_MACHINE "mips" #define UNAME_MINIMUM_RELEASE "2.6.32" diff --git a/linux-user/mips64/target_syscall.h b/linux-user/mips64/target_syscall.h index 0e0c2d232f..5789e86150 100644 --- a/linux-user/mips64/target_syscall.h +++ b/linux-user/mips64/target_syscall.h @@ -219,10 +219,6 @@ struct target_pt_regs { #define TARGET_ENOTRECOVERABLE 166 /* State not recoverable */ - -/* Nasty hack: define a fake errno value for use by sigreturn. */ -#define TARGET_QEMU_ESIGRETURN 255 - #define UNAME_MACHINE "mips64" #define UNAME_MINIMUM_RELEASE "2.6.32" diff --git a/linux-user/ppc/target_syscall.h b/linux-user/ppc/target_syscall.h index 35cab59462..7ca83c2280 100644 --- a/linux-user/ppc/target_syscall.h +++ b/linux-user/ppc/target_syscall.h @@ -53,8 +53,6 @@ struct target_revectored_struct { abi_ulong __map[8]; /* 256 bits */ }; -/* Nasty hack: define a fake errno value for use by sigreturn. */ -#define TARGET_QEMU_ESIGRETURN 255 /* * flags masks