From: David Mosberger <davidm@hpl.hp.com>
To: linux-ia64@vger.kernel.org
Subject: RE: [Linux-ia64] determining read or write on a page fault
Date: Sat, 23 Feb 2002 01:24:33 +0000 [thread overview]
Message-ID: <marc-linux-ia64-105590701905182@msgid-missing> (raw)
In-Reply-To: <marc-linux-ia64-105590701905163@msgid-missing>
If you want to try with a new kernel, the attached patch should give
you what you want. Specifically, if you get a SIGSEGV or a SIGBUS and
si_code is non-zero, you can check si_flags. If it has the
__ISR_VALID flag set, then the code in si_isr is valid. If si_isr is
valid, you can check whether bit 34 (read exception) or bit 35
(non-access exception) is set. If so, you may assume that the signal
was due to a load (or lfetch or some such). In all other cases, you'd
have to play it safe and assume that you're dealing with a write
access.
--david
diff -urN linux-2.4.17/arch/ia64/ia32/ia32_support.c lia64-2.4/arch/ia64/ia32/ia32_support.c
--- linux-2.4.17/arch/ia64/ia32/ia32_support.c Mon Nov 26 11:18:20 2001
+++ lia64-2.4/arch/ia64/ia32/ia32_support.c Fri Feb 22 16:37:53 2002
@@ -172,6 +174,10 @@
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = int_num; /* XXX is it OK to abuse si_errno like this? */
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_addr = 0;
+ siginfo.si_imm = 0;
siginfo.si_code = TRAP_BRKPT;
force_sig_info(SIGTRAP, &siginfo, current);
}
diff -urN linux-2.4.17/arch/ia64/ia32/ia32_traps.c lia64-2.4/arch/ia64/ia32/ia32_traps.c
--- linux-2.4.17/arch/ia64/ia32/ia32_traps.c Mon Nov 26 11:18:20 2001
+++ lia64-2.4/arch/ia64/ia32/ia32_traps.c Fri Feb 22 16:32:45 2002
@@ -2,7 +2,7 @@
* IA-32 exception handlers
*
* Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
- * Copyright (C) 2001 Hewlett-Packard Co
+ * Copyright (C) 2001-2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 06/16/00 A. Mallick added siginfo for most cases (close to IA32)
@@ -40,7 +40,11 @@
{
struct siginfo siginfo;
+ /* initialize these fields to avoid leaking kernel bits to user space: */
siginfo.si_errno = 0;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_imm = 0;
switch ((isr >> 16) & 0xff) {
case 1:
case 2:
@@ -103,6 +107,8 @@
* and it will suffer the consequences since we won't be able to
* fully reproduce the context of the exception
*/
+ siginfo.si_isr = isr;
+ siginfo.si_flags = __ISR_VALID;
switch(((~fcr) & (fsr & 0x3f)) | (fsr & 0x240)) {
case 0x000:
default:
diff -urN linux-2.4.17/arch/ia64/kernel/brl_emu.c lia64-2.4/arch/ia64/kernel/brl_emu.c
--- linux-2.4.17/arch/ia64/kernel/brl_emu.c Thu Apr 5 12:51:47 2001
+++ lia64-2.4/arch/ia64/kernel/brl_emu.c Fri Feb 22 16:39:55 2002
@@ -195,6 +195,9 @@
printk("Woah! Unimplemented Instruction Address Trap!\n");
siginfo.si_signo = SIGILL;
siginfo.si_errno = 0;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_imm = 0;
siginfo.si_code = ILL_BADIADDR;
force_sig_info(SIGILL, &siginfo, current);
} else if (ia64_psr(regs)->tb) {
@@ -205,6 +208,10 @@
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = 0;
siginfo.si_code = TRAP_BRANCH;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_addr = 0;
+ siginfo.si_imm = 0;
force_sig_info(SIGTRAP, &siginfo, current);
} else if (ia64_psr(regs)->ss) {
/*
@@ -214,6 +221,10 @@
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = 0;
siginfo.si_code = TRAP_TRACE;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_addr = 0;
+ siginfo.si_imm = 0;
force_sig_info(SIGTRAP, &siginfo, current);
}
return rv;
diff -urN linux-2.4.17/arch/ia64/kernel/signal.c lia64-2.4/arch/ia64/kernel/signal.c
--- linux-2.4.17/arch/ia64/kernel/signal.c Mon Nov 26 11:18:24 2001
+++ lia64-2.4/arch/ia64/kernel/signal.c Fri Feb 22 16:04:49 2002
@@ -160,6 +160,7 @@
err |= __put_user((short)from->si_code, &to->si_code);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
+ err |= __put_user(from->si_flags, &to->si_flags);
err |= __put_user(from->si_isr, &to->si_isr);
case __SI_POLL >> 16:
err |= __put_user(from->si_addr, &to->si_addr);
diff -urN linux-2.4.17/arch/ia64/kernel/traps.c lia64-2.4/arch/ia64/kernel/traps.c
--- linux-2.4.17/arch/ia64/kernel/traps.c Mon Nov 26 11:18:24 2001
+++ lia64-2.4/arch/ia64/kernel/traps.c Fri Feb 22 16:42:59 2002
@@ -1,7 +1,7 @@
/*
* Architecture-specific trap handling.
*
- * Copyright (C) 1998-2001 Hewlett-Packard Co
+ * Copyright (C) 1998-2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 05/12/00 grao <goutham.rao@intel.com> : added isr in siginfo for SIGFPE
@@ -133,6 +133,8 @@
/* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
siginfo.si_imm = break_num;
+ siginfo.si_flags = 0; /* clear __ISR_VALID */
+ siginfo.si_isr = 0;
switch (break_num) {
case 0: /* unknown error */
@@ -352,6 +354,8 @@
siginfo.si_code = FPE_FLTDIV;
}
siginfo.si_isr = isr;
+ siginfo.si_flags = __ISR_VALID;
+ siginfo.si_imm = 0;
force_sig_info(SIGFPE, &siginfo, current);
}
} else {
@@ -372,6 +376,8 @@
siginfo.si_code = FPE_FLTRES;
}
siginfo.si_isr = isr;
+ siginfo.si_flags = __ISR_VALID;
+ siginfo.si_imm = 0;
force_sig_info(SIGFPE, &siginfo, current);
}
}
@@ -490,6 +496,8 @@
siginfo.si_errno = 0;
siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
siginfo.si_imm = vector;
+ siginfo.si_flags = __ISR_VALID;
+ siginfo.si_isr = isr;
force_sig_info(SIGILL, &siginfo, current);
return;
}
@@ -517,6 +525,10 @@
}
siginfo.si_signo = SIGTRAP;
siginfo.si_errno = 0;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_addr = 0;
+ siginfo.si_imm = 0;
force_sig_info(SIGTRAP, &siginfo, current);
return;
@@ -528,6 +540,9 @@
siginfo.si_errno = 0;
siginfo.si_code = FPE_FLTINV;
siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
+ siginfo.si_flags = __ISR_VALID;
+ siginfo.si_isr = isr;
+ siginfo.si_imm = 0;
force_sig_info(SIGFPE, &siginfo, current);
}
return;
@@ -537,6 +552,9 @@
siginfo.si_signo = SIGILL;
siginfo.si_code = ILL_BADIADDR;
siginfo.si_errno = 0;
+ siginfo.si_flags = 0;
+ siginfo.si_isr = 0;
+ siginfo.si_imm = 0;
siginfo.si_addr = (void *) (regs->cr_iip + ia64_psr(regs)->ri);
force_sig_info(SIGILL, &siginfo, current);
return;
diff -urN linux-2.4.17/arch/ia64/kernel/unaligned.c lia64-2.4/arch/ia64/kernel/unaligned.c
--- linux-2.4.17/arch/ia64/kernel/unaligned.c Mon Nov 26 11:18:24 2001
+++ lia64-2.4/arch/ia64/kernel/unaligned.c Fri Feb 22 16:36:18 2002
@@ -1488,6 +1488,9 @@
si.si_errno = 0;
si.si_code = BUS_ADRALN;
si.si_addr = (void *) ifa;
+ si.si_flags = 0;
+ si.si_isr = 0;
+ si.si_imm = 0;
force_sig_info(SIGBUS, &si, current);
goto done;
}
diff -urN linux-2.4.17/arch/ia64/mm/fault.c lia64-2.4/arch/ia64/mm/fault.c
--- linux-2.4.17/arch/ia64/mm/fault.c Mon Nov 26 11:18:25 2001
+++ lia64-2.4/arch/ia64/mm/fault.c Fri Feb 22 15:52:41 2002
@@ -151,6 +151,8 @@
si.si_errno = 0;
si.si_code = code;
si.si_addr = (void *) address;
+ si.si_isr = isr;
+ si.si_flags = __ISR_VALID;
force_sig_info(signal, &si, current);
return;
}
diff -urN linux-2.4.17/include/asm-ia64/siginfo.h lia64-2.4/include/asm-ia64/siginfo.h
--- linux-2.4.17/include/asm-ia64/siginfo.h Wed Dec 26 16:58:57 2001
+++ lia64-2.4/include/asm-ia64/siginfo.h Fri Feb 22 16:49:28 2002
@@ -2,8 +2,8 @@
#define _ASM_IA64_SIGINFO_H
/*
- * Copyright (C) 1998-2001 Hewlett-Packard Co
- * Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com>
+ * Copyright (C) 1998-2002 Hewlett-Packard Co
+ * David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/types.h>
@@ -57,7 +57,7 @@
struct {
void *_addr; /* faulting insn/memory ref. */
int _imm; /* immediate value for "break" */
- int _pad0;
+ unsigned int _flags; /* see below */
unsigned long _isr; /* isr */
} _sigfault;
@@ -88,10 +88,21 @@
#define si_ptr _sifields._rt._sigval.sival_ptr
#define si_addr _sifields._sigfault._addr
#define si_imm _sifields._sigfault._imm /* as per UNIX SysV ABI spec */
-#define si_isr _sifields._sigfault._isr /* valid if si_code=FPE_FLTxxx */
+#define si_flags _sifields._sigfault._flags
+/*
+ * si_isr is valid for SIGILL, SIGFPE, SIGSEGV, SIGBUS, and SIGTRAP provided that
+ * si_code is non-zero and __ISR_VALID is set in si_flags.
+ */
+#define si_isr _sifields._sigfault._isr
#define si_band _sifields._sigpoll._band
#define si_fd _sifields._sigpoll._fd
#define si_pfm_ovfl _sifields._sigprof._pfm_ovfl_counters
+
+/*
+ * Flag values for si_flags:
+ */
+#define __ISR_VALID_BIT 0
+#define __ISR_VALID (1 << __ISR_VALID_BIT)
/*
* si_code values
next prev parent reply other threads:[~2002-02-23 1:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-21 21:09 [Linux-ia64] determining read or write on a page fault Hoeflinger, Jay P
2002-02-21 21:57 ` Boehm, Hans
2002-02-22 15:58 ` Hoeflinger, Jay P
2002-02-22 17:06 ` David Mosberger
2002-02-22 17:27 ` Hoeflinger, Jay P
2002-02-22 17:29 ` n0ano
2002-02-22 18:45 ` David Mosberger
2002-02-23 1:24 ` David Mosberger [this message]
2002-02-25 17:07 ` Hoeflinger, Jay P
2002-02-25 18:36 ` David Mosberger
2002-04-03 16:18 ` Hoeflinger, Jay P
2002-04-04 21:59 ` David Mosberger
2002-04-04 22:49 ` Neelakantam, NaveenX
2002-04-14 22:08 ` Neelakantam, NaveenX
2002-04-15 16:55 ` David Mosberger
2002-04-16 20:18 ` Neelakantam, NaveenX
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