From 13c06be399902c9ebda08e092edb1614bb4a3761 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 25 Sep 2006 23:32:59 -0700 Subject: [PATCH] uml: Use klibc setjmp/longjmp This patch adds an implementation of setjmp and longjmp to UML, allowing access to the inside of a jmpbuf without needing the access macros formerly provided by libc. The implementation is stolen from klibc. I copy the relevant files into arch/um. I have another patch which avoids the copying, but requires klibc be in the tree. setjmp and longjmp users required some tweaking. Includes of were removed and includes of the UML longjmp.h were added where necessary. There are also replacements of siglongjmp with UML_LONGJMP which I somehow missed earlier. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/os-Linux/sys-i386/registers.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/um/os-Linux/sys-i386/registers.c') diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c index 516f66dd87e3..1f90a2d71386 100644 --- a/arch/um/os-Linux/sys-i386/registers.c +++ b/arch/um/os-Linux/sys-i386/registers.c @@ -5,12 +5,12 @@ #include #include -#include #include "sysdep/ptrace_user.h" #include "sysdep/ptrace.h" #include "uml-config.h" #include "skas_ptregs.h" #include "registers.h" +#include "longjmp.h" #include "user.h" /* These are set once at boot time and not changed thereafter */ @@ -132,9 +132,9 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs) void get_thread_regs(union uml_pt_regs *uml_regs, void *buffer) { - struct __jmp_buf_tag *jmpbuf = buffer; + struct __jmp_buf *jmpbuf = buffer; - UPT_SET(uml_regs, EIP, jmpbuf->__jmpbuf[JB_PC]); - UPT_SET(uml_regs, UESP, jmpbuf->__jmpbuf[JB_SP]); - UPT_SET(uml_regs, EBP, jmpbuf->__jmpbuf[JB_BP]); + UPT_SET(uml_regs, EIP, jmpbuf->__eip); + UPT_SET(uml_regs, UESP, jmpbuf->__esp); + UPT_SET(uml_regs, EBP, jmpbuf->__ebp); } -- cgit v1.2.3 From 75e29b18d9a46bf3193278e92dc95609a8cca2ab Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 25 Sep 2006 23:33:08 -0700 Subject: [PATCH] uml: stack usage reduction 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/os-Linux/sys-i386/registers.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'arch/um/os-Linux/sys-i386/registers.c') diff --git a/arch/um/os-Linux/sys-i386/registers.c b/arch/um/os-Linux/sys-i386/registers.c index 1f90a2d71386..7cd0369e02b3 100644 --- a/arch/um/os-Linux/sys-i386/registers.c +++ b/arch/um/os-Linux/sys-i386/registers.c @@ -130,11 +130,14 @@ void get_safe_registers(unsigned long *regs, unsigned long *fp_regs) 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; + } } -- cgit v1.2.3