{"id":871,"url":"http://patchwork.ozlabs.org/api/1.0/patches/871/?format=json","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.0/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/"},"msgid":"<200809221841.27993.srinivasa@in.ibm.com>","date":"2008-09-22T13:11:27","name":"[RFC] Demultiplexing SIGTRAP signal","commit_ref":null,"pull_url":null,"state":"rfc","archived":true,"hash":"5f04221403a4d310b8408ce47d443d6f44c32728","submitter":{"id":390,"url":"http://patchwork.ozlabs.org/api/1.0/people/390/?format=json","name":"Srinivasa Ds","email":"srinivasa@in.ibm.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/200809221841.27993.srinivasa@in.ibm.com/mbox/","series":[],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/871/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@ozlabs.org"],"Received":["from ozlabs.org (localhost [127.0.0.1])\n\tby ozlabs.org (Postfix) with ESMTP id 62A96DDFC3\n\tfor ;\n\tMon, 22 Sep 2008 23:11:31 +1000 (EST)","from e23smtp02.au.ibm.com (E23SMTP02.au.ibm.com [202.81.18.163])\n\t(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))\n\t(Client CN \"e23smtp02.au.ibm.com\", Issuer \"Equifax\" (verified OK))\n\tby ozlabs.org (Postfix) with ESMTPS id 31282DDF11\n\tfor ; Mon, 22 Sep 2008 23:11:17 +1000 (EST)","from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225])\n\tby e23smtp02.au.ibm.com (8.13.1/8.13.1) with ESMTP id m8MDAQsH025626\n\tfor ; Mon, 22 Sep 2008 23:10:26 +1000","from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138])\n\tby sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id\n\tm8MDAbFn211470\n\tfor ; Mon, 22 Sep 2008 23:10:59 +1000","from d23av02.au.ibm.com (loopback [127.0.0.1])\n\tby d23av02.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id\n\tm8MDAbxo001866\n\tfor ; Mon, 22 Sep 2008 23:10:37 +1000","from srinivasa-009124031087.in.ibm.com\n\t(Srinivasa-009124031087.in.ibm.com [9.124.31.87])\n\tby d23av02.au.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id\n\tm8MDAZGC001626; Mon, 22 Sep 2008 23:10:35 +1000"],"From":"Srinivasa Ds ","Organization":"IBM","To":"Ingo Molnar ","Subject":"Re: [RFC][PATCH] Demultiplexing SIGTRAP signal","Date":"Mon, 22 Sep 2008 18:41:27 +0530","User-Agent":"KMail/1.9.9","References":"<200809221602.32616.srinivasa@in.ibm.com>\n\t<20080922104202.GE30137@elte.hu>","In-Reply-To":"<20080922104202.GE30137@elte.hu>","MIME-Version":"1.0","Content-Disposition":"inline","Message-Id":"<200809221841.27993.srinivasa@in.ibm.com>","Cc":"linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org,\n\tlinuxppc-dev@ozlabs.org, paulus@samba.org,\n\t\"H. Peter Anvin\" , akpm@linux-foundation.org,\n\tThomas Gleixner , Roland McGrath ","X-BeenThere":"linuxppc-dev@ozlabs.org","X-Mailman-Version":"2.1.11","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Sender":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org"},"content":"On Monday 22 September 2008 16:12:02 Ingo Molnar wrote:\n> no fundamental objections - assuming existing x86 apps have not grown an\n> ABI dependency on the existing send_sigtrap() semantics. (Debuggers and\n> JITs would be a candidate for such dependencies.)\n>\n\nAssuming that no ABI dependency exist between x86 apps and send_sigtrap(),\nAnd implementing some of the Ingo's suggestions, Iam resending the patch.\n\nStill waiting for Roland's reply.\n\n\nCurrently a SIGTRAP can denote any one of below reasons.\n\t- Breakpoint hit\n\t- H/W debug register hit\n\t- Single step\n\t- Signal sent through kill() or rasie()\n\nArchitectures like powerpc/parisc provides infrastructure to demultiplex\nSIGTRAP signal by passing down the information for receiving SIGTRAP through\nsi_code of siginfot_t strucutre. Here is an attempt is generalise this \ninfrasturcutre by extending it to x86 and x86_64 archs. \n\nSigned-off-by: Srinivasa DS \n\n---\n arch/ia64/include/asm/siginfo.h | 5 -----\n arch/powerpc/include/asm/siginfo.h | 5 -----\n arch/x86/kernel/ptrace.c | 7 ++++---\n arch/x86/kernel/traps_32.c | 4 +++-\n arch/x86/kernel/traps_64.c | 2 +-\n include/asm-generic/siginfo.h | 2 ++\n include/asm-parisc/siginfo.h | 5 -----\n include/asm-x86/ptrace.h | 2 +-\n include/asm-x86/traps.h | 10 ++++++++++\n 9 files changed, 21 insertions(+), 21 deletions(-)","diff":"Index: linux-2.6.27-rc7/arch/ia64/include/asm/siginfo.h\n===================================================================\n--- linux-2.6.27-rc7.orig/arch/ia64/include/asm/siginfo.h\n+++ linux-2.6.27-rc7/arch/ia64/include/asm/siginfo.h\n@@ -113,11 +113,6 @@ typedef struct siginfo {\n #undef NSIGSEGV\n #define NSIGSEGV\t3\n \n-/*\n- * SIGTRAP si_codes\n- */\n-#define TRAP_BRANCH\t(__SI_FAULT|3)\t/* process taken branch trap */\n-#define TRAP_HWBKPT\t(__SI_FAULT|4)\t/* hardware breakpoint or watchpoint */\n #undef NSIGTRAP\n #define NSIGTRAP\t4\n \nIndex: linux-2.6.27-rc7/arch/powerpc/include/asm/siginfo.h\n===================================================================\n--- linux-2.6.27-rc7.orig/arch/powerpc/include/asm/siginfo.h\n+++ linux-2.6.27-rc7/arch/powerpc/include/asm/siginfo.h\n@@ -15,11 +15,6 @@\n \n #include \n \n-/*\n- * SIGTRAP si_codes\n- */\n-#define TRAP_BRANCH\t(__SI_FAULT|3)\t/* process taken branch trap */\n-#define TRAP_HWBKPT\t(__SI_FAULT|4)\t/* hardware breakpoint or watchpoint */\n #undef NSIGTRAP\n #define NSIGTRAP\t4\n \nIndex: linux-2.6.27-rc7/arch/x86/kernel/traps_32.c\n===================================================================\n--- linux-2.6.27-rc7.orig/arch/x86/kernel/traps_32.c\n+++ linux-2.6.27-rc7/arch/x86/kernel/traps_32.c\n@@ -891,6 +891,7 @@ void __kprobes do_debug(struct pt_regs *\n {\n \tstruct task_struct *tsk = current;\n \tunsigned int condition;\n+\tint si_code;\n \n \ttrace_hardirqs_fixup();\n \n@@ -935,8 +936,9 @@ void __kprobes do_debug(struct pt_regs *\n \t\t\tgoto clear_TF_reenable;\n \t}\n \n+\tsi_code = get_si_code((unsigned long*)&condition);\n \t/* Ok, finally something we can handle */\n-\tsend_sigtrap(tsk, regs, error_code);\n+\tsend_sigtrap(tsk, regs, error_code, si_code);\n \n \t/*\n \t * Disable additional traps. They'll be re-enabled when\nIndex: linux-2.6.27-rc7/arch/x86/kernel/traps_64.c\n===================================================================\n--- linux-2.6.27-rc7.orig/arch/x86/kernel/traps_64.c\n+++ linux-2.6.27-rc7/arch/x86/kernel/traps_64.c\n@@ -936,7 +936,7 @@ asmlinkage void __kprobes do_debug(struc\n \ttsk->thread.error_code = error_code;\n \tinfo.si_signo = SIGTRAP;\n \tinfo.si_errno = 0;\n-\tinfo.si_code = TRAP_BRKPT;\n+\tinfo.si_code = get_si_code(&condition);\n \tinfo.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;\n \tforce_sig_info(SIGTRAP, &info, tsk);\n \nIndex: linux-2.6.27-rc7/include/asm-generic/siginfo.h\n===================================================================\n--- linux-2.6.27-rc7.orig/include/asm-generic/siginfo.h\n+++ linux-2.6.27-rc7/include/asm-generic/siginfo.h\n@@ -199,6 +199,8 @@ typedef struct siginfo {\n */\n #define TRAP_BRKPT\t(__SI_FAULT|1)\t/* process breakpoint */\n #define TRAP_TRACE\t(__SI_FAULT|2)\t/* process trace trap */\n+#define TRAP_BRANCH (__SI_FAULT|3) /* process taken branch trap */\n+#define TRAP_HWBKPT (__SI_FAULT|4) /* hardware breakpoint or watchpoint \n*/\n #define NSIGTRAP\t2\n \n /*\nIndex: linux-2.6.27-rc7/include/asm-parisc/siginfo.h\n===================================================================\n--- linux-2.6.27-rc7.orig/include/asm-parisc/siginfo.h\n+++ linux-2.6.27-rc7/include/asm-parisc/siginfo.h\n@@ -3,11 +3,6 @@\n \n #include \n \n-/*\n- * SIGTRAP si_codes\n- */\n-#define TRAP_BRANCH\t(__SI_FAULT|3)\t/* process taken branch trap */\n-#define TRAP_HWBKPT\t(__SI_FAULT|4)\t/* hardware breakpoint or watchpoint */\n #undef NSIGTRAP\n #define NSIGTRAP\t4\n \nIndex: linux-2.6.27-rc7/arch/x86/kernel/ptrace.c\n===================================================================\n--- linux-2.6.27-rc7.orig/arch/x86/kernel/ptrace.c\n+++ linux-2.6.27-rc7/arch/x86/kernel/ptrace.c\n@@ -1357,7 +1357,8 @@ const struct user_regset_view *task_user\n #endif\n }\n \n-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int \nerror_code)\n+void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int \nerror_code,\n+\t\t\t\t\t\t\t int si_code)\n {\n \tstruct siginfo info;\n \n@@ -1366,7 +1367,7 @@ void send_sigtrap(struct task_struct *ts\n \n \tmemset(&info, 0, sizeof(info));\n \tinfo.si_signo = SIGTRAP;\n-\tinfo.si_code = TRAP_BRKPT;\n+\tinfo.si_code = si_code;\n \n \t/* User-mode ip? */\n \tinfo.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;\n@@ -1476,5 +1477,5 @@ asmregparm void syscall_trace_leave(stru\n \t */\n \tif (test_thread_flag(TIF_SINGLESTEP) &&\n \t (current->ptrace & PT_PTRACED))\n-\t\tsend_sigtrap(current, regs, 0);\n+\t\tsend_sigtrap(current, regs, 0, TRAP_BRKPT);\n }\nIndex: linux-2.6.27-rc7/include/asm-x86/traps.h\n===================================================================\n--- linux-2.6.27-rc7.orig/include/asm-x86/traps.h\n+++ linux-2.6.27-rc7/include/asm-x86/traps.h\n@@ -36,6 +36,16 @@ void do_invalid_op(struct pt_regs *, lon\n void do_general_protection(struct pt_regs *, long);\n void do_nmi(struct pt_regs *, long);\n \n+int get_si_code(unsigned long *condition)\n+{\n+\tif (*condition & DR_STEP)\n+\t\treturn TRAP_TRACE;\n+\telse if (*condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3))\n+\t\treturn TRAP_HWBKPT;\n+\telse\n+\t\treturn TRAP_BRKPT;\n+}\n+\n extern int panic_on_unrecovered_nmi;\n extern int kstack_depth_to_print;\n \nIndex: linux-2.6.27-rc7/include/asm-x86/ptrace.h\n===================================================================\n--- linux-2.6.27-rc7.orig/include/asm-x86/ptrace.h\n+++ linux-2.6.27-rc7/include/asm-x86/ptrace.h\n@@ -143,7 +143,7 @@ convert_ip_to_linear(struct task_struct \n \n #ifdef CONFIG_X86_32\n extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,\n-\t\t\t int error_code);\n+\t\t\t int error_code, int si_code);\n #else\n void signal_fault(struct pt_regs *regs, void __user *frame, char *where);\n #endif\n","prefixes":["RFC"]}