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MIPS: Kprobe support v0.2

PATCH New Himanshu Chauhan 1 participant 2 messages Jun 12, 2010 1 message not in the archive MIPS

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Himanshu Chauhan

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PATCH 1/1 MIPS: Kprobe support v0.2

This updated version of patch incorporates some of the comments from Daney. The list of changes are as follows:
o Instead of separate handler "do_break", do_bp is used to track and handle kprobe induced breaks. This cleans up ugly ifdef hack.
o Instead of using 0 and 5 code in break, new kprobe specific defines (515, 516) have been added and handled.

The use of notify_die could not be dropped because the kprobes framework installs handlers on notify_die chain.

Himanshu Chauhan (1):
MIPS: Kprobe support v0.2 This incorporates some of the comments
from Daney.

 arch/mips/Kconfig               |   13 ++
 arch/mips/include/asm/break.h   |    2 +
 arch/mips/include/asm/kdebug.h  |    5 +
 arch/mips/include/asm/kprobes.h |   86 +++++++++
 arch/mips/kernel/Makefile       |    2 +
 arch/mips/kernel/kprobes.c      |  379 +++++++++++++++++++++++++++++++++++++++
 arch/mips/kernel/traps.c        |   46 +++++-
 arch/mips/mm/fault.c            |   11 +-
 8 files changed, 541 insertions(+), 3 deletions(-)
 create mode 100644 arch/mips/include/asm/kprobes.h
 create mode 100644 arch/mips/kernel/kprobes.c
author
#2 lore raw

PATCH 1/1 MIPS: Kprobe support v0.2 This incorporates some of the comments from Daney.

In reply to a message not in the archive
Signed-off-by Himanshu Chauhan <[email protected]>
---
 arch/mips/Kconfig               |   13 ++
 arch/mips/include/asm/break.h   |    2 +
 arch/mips/include/asm/kdebug.h  |    5 +
 arch/mips/include/asm/kprobes.h |   86 +++++++++
 arch/mips/kernel/Makefile       |    2 +
 arch/mips/kernel/kprobes.c      |  379 +++++++++++++++++++++++++++++++++++++++
 arch/mips/kernel/traps.c        |   46 +++++-
 arch/mips/mm/fault.c            |   11 +-
 8 files changed, 541 insertions(+), 3 deletions(-)
 create mode 100644 arch/mips/include/asm/kprobes.h
 create mode 100644 arch/mips/kernel/kprobes.c
arch/mips/Kconfig +13 -0
index cdaae94..ba7cc87 100644
@@ -2243,6 +2243,19 @@ source "kernel/power/Kconfig"
 
 endmenu
 
+menu "Instrumentation Support"
+
+config KPROBES
+       bool "MIPS Kprobes Support (Experimental)"
+       depends on EXPERIMENTAL && MODULES
+       help
+	  Kprobes allow you to trap at almost any kernel address
+	  and execute a callback function. Kprobes is useful for
+	  kernel debugging, non-intrusive instrumetation and testing.
+	  If in doubt, say N.
+
+endmenu
+
 source "arch/mips/kernel/cpufreq/Kconfig"
 
 source "net/Kconfig"
arch/mips/include/asm/break.h +2 -0
index 44437ed..9ee3014 100644
@@ -30,6 +30,8 @@
 #define BRK_BUG		512	/* Used by BUG() */
 #define BRK_KDB		513	/* Used in KDB_ENTER() */
 #define BRK_MEMU	514	/* Used by FPU emulator */
+#define BRK_KPRB_BP	515	/* Used by Kprobes for pre-handling */
+#define BRK_KPRB_SSTP	516	/* Used by Kprobes for post-handling */
 #define BRK_MULOVF	1023	/* Multiply overflow */
 
 #endif /* __ASM_BREAK_H */
arch/mips/include/asm/kdebug.h +5 -0
index 5bf62aa..52818ac 100644
@@ -8,6 +8,11 @@ enum die_val {
 	DIE_FP,
 	DIE_TRAP,
 	DIE_RI,
+#ifdef CONFIG_KPROBES
+	DIE_PAGE_FAULT,
+	DIE_BREAK,
+	DIE_SSTEPBP,
+#endif
 };
 
 #endif /* _ASM_MIPS_KDEBUG_H */
arch/mips/include/asm/kprobes.h new file +86 -0

86 lines not on this page · raw message

arch/mips/kernel/Makefile +2 -0
index 7a6ac50..714f3c1 100644
@@ -83,6 +83,7 @@ obj-$(CONFIG_MIPS32_N32)	+= binfmt_elfn32.o scall64-n32.o signal_n32.o
 obj-$(CONFIG_MIPS32_O32)	+= binfmt_elfo32.o scall64-o32.o
 
 obj-$(CONFIG_KGDB)		+= kgdb.o
+obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_PROC_FS)		+= proc.o
 
 obj-$(CONFIG_64BIT)		+= cpu-bugs64.o

@@ -95,6 +96,7 @@ obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_SPINLOCK_TEST)	+= spinlock_test.o
 
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)	+= 8250-platform.o
arch/mips/kernel/kprobes.c new file +379 -0

379 lines not on this page · raw message

arch/mips/kernel/traps.c +45 -1

76 lines not on this page · raw message

arch/mips/mm/fault.c +9 -2
index b78f7d9..86e2d27 100644
@@ -18,6 +18,8 @@
 #include <linux/smp.h>
 #include <linux/vt_kern.h>		/* For unblank_screen() */
 #include <linux/module.h>
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>		/* notify_die and asm/kdebug.h */
 
 #include <asm/branch.h>
 #include <asm/mmu_context.h>

@@ -31,8 +33,8 @@
  * and the problem, and then passes it off to one of the appropriate
  * routines.
  */
-asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
-			      unsigned long address)
+asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long write,
+                                        unsigned long address)
 {
 	struct vm_area_struct * vma = NULL;
 	struct task_struct *tsk = current;

@@ -47,6 +49,11 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
 	       field, regs->cp0_epc);
 #endif
 
+	/* Notify kprobes fault handler. */
+        if (notify_die(DIE_PAGE_FAULT, "page fault",
+                       regs, -1, SEGV_MAPERR, SEGV_MAPERR) == NOTIFY_STOP)
+                return;
+
 	info.si_code = SEGV_MAPERR;
 
 	/*
Signature · 1 line
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