From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 22 Jun 2012 16:06:59 +0100 Subject: [RFC PATCH 1/8] Revert "arm: remove unused restart trampoline" In-Reply-To: <1340377626-17075-1-git-send-email-will.deacon@arm.com> References: <1340377626-17075-1-git-send-email-will.deacon@arm.com> Message-ID: <1340377626-17075-2-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This reverts commit fa18484d0947b976a769d15c83c50617493c81c1. We need the restart trampoline back so that we can revert a related problematic patch 6b5c8045ecc7e726cdaa2a9d9c8e5008050e1252 ("arm: new way of handling ERESTART_RESTARTBLOCK"). Acked-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm/kernel/signal.c | 13 +++++++++++++ arch/arm/kernel/signal.h | 2 ++ arch/arm/kernel/traps.c | 2 ++ 3 files changed, 17 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index fd2392a..6d3bce5 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -27,6 +27,7 @@ */ #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE)) #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE)) +#define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE) /* * With EABI, the syscall number has to be loaded into r7. @@ -47,6 +48,18 @@ const unsigned long sigreturn_codes[7] = { }; /* + * Either we support OABI only, or we have EABI with the OABI + * compat layer enabled. In the later case we don't know if + * user space is EABI or not, and if not we must not clobber r7. + * Always using the OABI syscall solves that issue and works for + * all those cases. + */ +const unsigned long syscall_restart_code[2] = { + SWI_SYS_RESTART, /* swi __NR_restart_syscall */ + 0xe49df004, /* ldr pc, [sp], #4 */ +}; + +/* * atomically swap in the new signal mask, and wait for a signal. */ asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask) diff --git a/arch/arm/kernel/signal.h b/arch/arm/kernel/signal.h index 5ff067b7..6fcfe83 100644 --- a/arch/arm/kernel/signal.h +++ b/arch/arm/kernel/signal.h @@ -8,5 +8,7 @@ * published by the Free Software Foundation. */ #define KERN_SIGRETURN_CODE (CONFIG_VECTORS_BASE + 0x00000500) +#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes)) extern const unsigned long sigreturn_codes[7]; +extern const unsigned long syscall_restart_code[2]; diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 4928d89..3647170 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -820,6 +820,8 @@ void __init early_trap_init(void *vectors_base) */ memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), sigreturn_codes, sizeof(sigreturn_codes)); + memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), + syscall_restart_code, sizeof(syscall_restart_code)); flush_icache_range(vectors, vectors + PAGE_SIZE); modify_domain(DOMAIN_USER, DOMAIN_CLIENT); -- 1.7.4.1