From 9ec4b1f356b3bad928ae8e2aa9caebfa737d52df Mon Sep 17 00:00:00 2001 From: Ananth N Mavinakayanahalli Date: Mon, 27 Jun 2005 15:17:01 -0700 Subject: [PATCH] kprobes: fix single-step out of line - take2 Now that PPC64 has no-execute support, here is a second try to fix the single step out of line during kprobe execution. Kprobes on x86_64 already solved this problem by allocating an executable page and using it as the scratch area for stepping out of line. Reuse that. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-ppc64/kprobes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-ppc64/kprobes.h') diff --git a/include/asm-ppc64/kprobes.h b/include/asm-ppc64/kprobes.h index 19b468bed05..790cf7c5277 100644 --- a/include/asm-ppc64/kprobes.h +++ b/include/asm-ppc64/kprobes.h @@ -45,7 +45,7 @@ typedef unsigned int kprobe_opcode_t; /* Architecture specific copy of original instruction */ struct arch_specific_insn { /* copy of original instruction */ - kprobe_opcode_t insn[MAX_INSN_SIZE]; + kprobe_opcode_t *insn; }; #ifdef CONFIG_KPROBES -- cgit v1.2.3 From 97f7943d70ff0e1e92ea627c44cfacfdae65dbc4 Mon Sep 17 00:00:00 2001 From: Rusty Lynch Date: Mon, 27 Jun 2005 15:17:15 -0700 Subject: [PATCH] Return probe redesign: ppc64 specific implementation The following is a patch provided by Ananth Mavinakayanahalli that implements the new PPC64 specific parts of the new function return probe design. NOTE: Since getting Ananth's patch, I changed trampoline_probe_handler() to consume each of the outstanding return probem instances (feedback on my original RFC after Ananth cut a patch), and also added the arch_init() function (adding arch specific initialization.) I have cross compiled but have not testing this on a PPC64 machine. Changes include: * Addition of kretprobe_trampoline to act as a dummy function for instrumented functions to return to, and for the return probe infrastructure to place a kprobe on on, gaining control so that the return probe handler can be called, and so that the instruction pointer can be moved back to the original return address. * Addition of arch_init(), allowing a kprobe to be registered on kretprobe_trampoline * Addition of trampoline_probe_handler() which is used as the pre_handler for the kprobe inserted on kretprobe_implementation. This is the function that handles the details for calling the return probe handler function and returning control back at the original return address * Addition of arch_prepare_kretprobe() which is setup as the pre_handler for a kprobe registered at the beginning of the target function by kernel/kprobes.c so that a return probe instance can be setup when a caller enters the target function. (A return probe instance contains all the needed information for trampoline_probe_handler to do it's job.) * Hooks added to the exit path of a task so that we can cleanup any left-over return probe instances (i.e. if a task dies while inside a targeted function then the return probe instance was reserved at the beginning of the function but the function never returns so we need to mark the instance as unused.) Signed-off-by: Rusty Lynch Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-ppc64/kprobes.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/asm-ppc64/kprobes.h') diff --git a/include/asm-ppc64/kprobes.h b/include/asm-ppc64/kprobes.h index 790cf7c5277..0802919c323 100644 --- a/include/asm-ppc64/kprobes.h +++ b/include/asm-ppc64/kprobes.h @@ -42,6 +42,9 @@ typedef unsigned int kprobe_opcode_t; #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry) +#define ARCH_SUPPORTS_KRETPROBES +void kretprobe_trampoline(void); + /* Architecture specific copy of original instruction */ struct arch_specific_insn { /* copy of original instruction */ -- cgit v1.2.3