Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1GAzlW-00059j-Ez for user-mode-linux-devel@lists.sourceforge.net; Wed, 09 Aug 2006 18:55:18 -0700 Received: from saraswathi.solana.com ([198.99.130.12]) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1GAzlV-0001fY-UO for user-mode-linux-devel@lists.sourceforge.net; Wed, 09 Aug 2006 18:55:18 -0700 Message-Id: <200608091815.k79IFW3W005315@ccure.user-mode-linux.org> Mime-Version: 1.0 Date: Wed, 09 Aug 2006 14:15:30 -0400 From: Jeff Dike Subject: [uml-devel] [PATCH] UML - Stack usage reduction List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net The KSTK_* macros used an inordinate amount of stack. In order to overcome an impedance mismatch between their interface, which just returns a single register value, and the interface of get_thread_regs, which took a full pt_regs, the implementation created an on-stack pt_regs, filled it in, and returned one field. do_task_stat calls KSTK_* twice, resulting in two local pt_regs, blowing out the stack. This patch changes the interface (and name) of get_thread_regs to just return a single register from a jmp_buf. The include of archsetjmp.h" in registers.h to get the definition of jmp_buf exposed a bogus include of in start_up.c. shouldn't be used anywhere any more since UML uses the klibc setjmp/longjmp. Signed-off-by: Jeff Dike Index: linux-2.6.17/arch/um/include/registers.h =================================================================== --- linux-2.6.17.orig/arch/um/include/registers.h 2006-06-17 21:49:35.000000000 -0400 +++ linux-2.6.17/arch/um/include/registers.h 2006-08-09 13:42:06.000000000 -0400 @@ -7,6 +7,7 @@ #define __REGISTERS_H #include "sysdep/ptrace.h" +#include "sysdep/archsetjmp.h" extern void init_thread_registers(union uml_pt_regs *to); extern int save_fp_registers(int pid, unsigned long *fp_regs); @@ -15,6 +16,6 @@ extern void save_registers(int pid, unio extern void restore_registers(int pid, union uml_pt_regs *regs); extern void init_registers(int pid); extern void get_safe_registers(unsigned long * regs, unsigned long * fp_regs); -extern void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer); +extern unsigned long get_thread_reg(int reg, jmp_buf *buf); #endif Index: linux-2.6.17/arch/um/os-Linux/sys-i386/registers.c =================================================================== --- linux-2.6.17.orig/arch/um/os-Linux/sys-i386/registers.c 2006-08-09 13:36:17.000000000 -0400 +++ linux-2.6.17/arch/um/os-Linux/sys-i386/registers.c 2006-08-09 13:42:06.000000000 -0400 @@ -130,11 +130,14 @@ void get_safe_registers(unsigned long *r HOST_FP_SIZE * sizeof(unsigned long)); } -void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer) +unsigned long get_thread_reg(int reg, jmp_buf *buf) { - struct __jmp_buf *jmpbuf = buffer; - - UPT_SET(uml_regs, EIP, jmpbuf->__eip); - UPT_SET(uml_regs, UESP, jmpbuf->__esp); - UPT_SET(uml_regs, EBP, jmpbuf->__ebp); + switch(reg){ + case EIP: return buf[0]->__eip; + case UESP: return buf[0]->__esp; + case EBP: return buf[0]->__ebp; + default: + printk("get_thread_regs - unknown register %d\n", reg); + return 0; + } } Index: linux-2.6.17/arch/um/os-Linux/sys-x86_64/registers.c =================================================================== --- linux-2.6.17.orig/arch/um/os-Linux/sys-x86_64/registers.c 2006-08-09 13:36:17.000000000 -0400 +++ linux-2.6.17/arch/um/os-Linux/sys-x86_64/registers.c 2006-08-09 13:42:06.000000000 -0400 @@ -78,11 +78,14 @@ void get_safe_registers(unsigned long *r HOST_FP_SIZE * sizeof(unsigned long)); } -void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer) +unsigned long get_thread_reg(int reg, jmp_buf *buf) { - struct __jmp_buf *jmpbuf = buffer; - - UPT_SET(uml_regs, RIP, jmpbuf->__rip); - UPT_SET(uml_regs, RSP, jmpbuf->__rsp); - UPT_SET(uml_regs, RBP, jmpbuf->__rbp); + switch(reg){ + case RIP: return buf[0]->__rip; + case RSP: return buf[0]->__rsp; + case RBP: return buf[0]->__rbp; + default: + printk("get_thread_regs - unknown register %d\n", reg); + return 0; + } } Index: linux-2.6.17/include/asm-um/processor-generic.h =================================================================== --- linux-2.6.17.orig/include/asm-um/processor-generic.h 2006-08-09 13:35:31.000000000 -0400 +++ linux-2.6.17/include/asm-um/processor-generic.h 2006-08-09 13:42:06.000000000 -0400 @@ -138,9 +138,7 @@ extern struct cpuinfo_um cpu_data[]; #ifdef CONFIG_MODE_SKAS #define KSTK_REG(tsk, reg) \ - ({ union uml_pt_regs regs; \ - get_thread_regs(®s, tsk->thread.mode.skas.switch_buf); \ - UPT_REG(®s, reg); }) + get_thread_reg(reg, tsk->thread.mode.skas.switch_buf) #else #define KSTK_REG(tsk, reg) (0xbadbabe) #endif Index: linux-2.6.17/arch/um/os-Linux/start_up.c =================================================================== --- linux-2.6.17.orig/arch/um/os-Linux/start_up.c 2006-08-09 13:56:44.000000000 -0400 +++ linux-2.6.17/arch/um/os-Linux/start_up.c 2006-08-09 13:56:54.000000000 -0400 @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel