From: Sven Schnelle <svens@stackframe.org>
To: deller@gmx.de
Cc: linux-parisc@vger.kernel.org, Sven Schnelle <svens@stackframe.org>
Subject: [PATCH 2/4] parisc/ftrace: Add KPROBES_ON_FTRACE
Date: Tue, 23 Jul 2019 22:37:52 +0200 [thread overview]
Message-ID: <20190723203754.7126-3-svens@stackframe.org> (raw)
In-Reply-To: <20190723203754.7126-1-svens@stackframe.org>
Allow KPROBES to use the ftrace infrastructure on PA-RISC.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
---
.../debug/kprobes-on-ftrace/arch-support.txt | 2 +-
arch/parisc/Kconfig | 2 +
arch/parisc/kernel/entry.S | 99 +++++++++++++++++++
arch/parisc/kernel/ftrace.c | 58 ++++++++++-
4 files changed, 157 insertions(+), 4 deletions(-)
diff --git a/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt b/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
index 68f266944d5f..4fae0464ddff 100644
--- a/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
+++ b/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
@@ -21,7 +21,7 @@
| nds32: | TODO |
| nios2: | TODO |
| openrisc: | TODO |
- | parisc: | TODO |
+ | parisc: | ok |
| powerpc: | ok |
| riscv: | TODO |
| s390: | TODO |
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6d732e451071..ee59171edffe 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -61,6 +61,8 @@ config PARISC
select HAVE_KRETPROBES
select HAVE_DYNAMIC_FTRACE if $(cc-option,-fpatchable-function-entry=1,1)
select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
+ select HAVE_KPROBES_ON_FTRACE
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index d9d3387f7c47..1d1d748c227f 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1996,6 +1996,7 @@ _mcount:
* calling mcount(), and 2 instructions for ftrace_stub(). That way we
* have all on one L1 cacheline.
*/
+ ldi 0, %arg3
b ftrace_function_trampoline
copy %r3, %arg2 /* caller original %sp */
ftrace_stub:
@@ -2048,6 +2049,7 @@ ftrace_caller:
LDREG 0(%r3), %r25
copy %rp, %r26
ldo -8(%r25), %r25
+ ldi 0, %r23 /* no pt_regs */
b,l ftrace_function_trampoline, %rp
copy %r3, %r24
@@ -2075,6 +2077,103 @@ ftrace_caller:
ENDPROC_CFI(ftrace_caller)
+#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS
+ENTRY_CFI(ftrace_regs_caller,caller,frame=FTRACE_FRAME_SIZE+PT_SZ_ALGN,
+ CALLS,SAVE_RP,SAVE_SP)
+ftrace_regs_caller:
+ .global ftrace_regs_caller
+
+ ldo -FTRACE_FRAME_SIZE(%sp), %r1
+ STREG %rp, -RP_OFFSET(%r1)
+
+ copy %sp, %r1
+ ldo PT_SZ_ALGN(%sp), %sp
+
+ STREG %rp, PT_GR2(%r1)
+ STREG %r3, PT_GR3(%r1)
+ STREG %r4, PT_GR4(%r1)
+ STREG %r5, PT_GR5(%r1)
+ STREG %r6, PT_GR6(%r1)
+ STREG %r7, PT_GR7(%r1)
+ STREG %r8, PT_GR8(%r1)
+ STREG %r9, PT_GR9(%r1)
+ STREG %r10, PT_GR10(%r1)
+ STREG %r11, PT_GR11(%r1)
+ STREG %r12, PT_GR12(%r1)
+ STREG %r13, PT_GR13(%r1)
+ STREG %r14, PT_GR14(%r1)
+ STREG %r15, PT_GR15(%r1)
+ STREG %r16, PT_GR16(%r1)
+ STREG %r17, PT_GR17(%r1)
+ STREG %r18, PT_GR18(%r1)
+ STREG %r19, PT_GR19(%r1)
+ STREG %r20, PT_GR20(%r1)
+ STREG %r21, PT_GR21(%r1)
+ STREG %r22, PT_GR22(%r1)
+ STREG %r23, PT_GR23(%r1)
+ STREG %r24, PT_GR24(%r1)
+ STREG %r25, PT_GR25(%r1)
+ STREG %r26, PT_GR26(%r1)
+ STREG %r27, PT_GR27(%r1)
+ STREG %r28, PT_GR28(%r1)
+ STREG %r29, PT_GR29(%r1)
+ STREG %r30, PT_GR30(%r1)
+ STREG %r31, PT_GR31(%r1)
+ mfctl %cr11, %r26
+ STREG %r26, PT_SAR(%r1)
+
+ copy %rp, %r26
+ LDREG -FTRACE_FRAME_SIZE-PT_SZ_ALGN(%sp), %r25
+ ldo -8(%r25), %r25
+ copy %r3, %arg2
+ b,l ftrace_function_trampoline, %rp
+ copy %r1, %arg3 /* struct pt_regs */
+
+ ldo -PT_SZ_ALGN(%sp), %r1
+
+ LDREG PT_SAR(%r1), %rp
+ mtctl %rp, %cr11
+
+ LDREG PT_GR2(%r1), %rp
+ LDREG PT_GR3(%r1), %r3
+ LDREG PT_GR4(%r1), %r4
+ LDREG PT_GR5(%r1), %r5
+ LDREG PT_GR6(%r1), %r6
+ LDREG PT_GR7(%r1), %r7
+ LDREG PT_GR8(%r1), %r8
+ LDREG PT_GR9(%r1), %r9
+ LDREG PT_GR10(%r1),%r10
+ LDREG PT_GR11(%r1),%r11
+ LDREG PT_GR12(%r1),%r12
+ LDREG PT_GR13(%r1),%r13
+ LDREG PT_GR14(%r1),%r14
+ LDREG PT_GR15(%r1),%r15
+ LDREG PT_GR16(%r1),%r16
+ LDREG PT_GR17(%r1),%r17
+ LDREG PT_GR18(%r1),%r18
+ LDREG PT_GR19(%r1),%r19
+ LDREG PT_GR20(%r1),%r20
+ LDREG PT_GR21(%r1),%r21
+ LDREG PT_GR22(%r1),%r22
+ LDREG PT_GR23(%r1),%r23
+ LDREG PT_GR24(%r1),%r24
+ LDREG PT_GR25(%r1),%r25
+ LDREG PT_GR26(%r1),%r26
+ LDREG PT_GR27(%r1),%r27
+ LDREG PT_GR28(%r1),%r28
+ LDREG PT_GR29(%r1),%r29
+ LDREG PT_GR30(%r1),%r30
+ LDREG PT_GR31(%r1),%r31
+
+ ldo -PT_SZ_ALGN(%sp), %sp
+ LDREGM -FTRACE_FRAME_SIZE(%sp), %r1
+ /* Adjust return point to jump back to beginning of traced function */
+ ldo -4(%r1), %r1
+ bv,n (%r1)
+
+ENDPROC_CFI(ftrace_regs_caller)
+
+#endif
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
index ea5c50de0b65..2c6086dbfe68 100644
--- a/arch/parisc/kernel/ftrace.c
+++ b/arch/parisc/kernel/ftrace.c
@@ -13,6 +13,8 @@
#include <linux/init.h>
#include <linux/ftrace.h>
#include <linux/uaccess.h>
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
#include <asm/assembly.h>
#include <asm/sections.h>
@@ -48,7 +50,8 @@ static void __hot prepare_ftrace_return(unsigned long *parent,
void notrace __hot ftrace_function_trampoline(unsigned long parent,
unsigned long self_addr,
- unsigned long org_sp_gr3)
+ unsigned long org_sp_gr3,
+ struct pt_regs *regs)
{
#ifndef CONFIG_DYNAMIC_FTRACE
extern ftrace_func_t ftrace_trace_function;
@@ -58,11 +61,11 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent,
if (function_trace_op->flags & FTRACE_OPS_FL_ENABLED &&
ftrace_trace_function != ftrace_stub)
ftrace_trace_function(self_addr, parent,
- function_trace_op, NULL);
+ function_trace_op, regs);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
- ftrace_graph_entry != ftrace_graph_entry_stub) {
+ ftrace_graph_entry != ftrace_graph_entry_stub) {
unsigned long *parent_rp;
/* calculate pointer to %rp in stack */
@@ -100,6 +103,12 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
return 0;
}
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+ unsigned long addr)
+{
+ return 0;
+}
+
unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr+(FTRACE_PATCHABLE_FUNCTION_SIZE-1)*4;
@@ -190,3 +199,46 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
return 0;
}
#endif
+
+#ifdef CONFIG_KPROBES_ON_FTRACE
+void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb;
+ struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
+
+ if (unlikely(!p) || kprobe_disabled(p))
+ return;
+
+ if (kprobe_running()) {
+ kprobes_inc_nmissed_count(p);
+ return;
+ }
+
+ __this_cpu_write(current_kprobe, p);
+
+ kcb = get_kprobe_ctlblk();
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+ regs->iaoq[0] = ip;
+ regs->iaoq[1] = ip + 4;
+
+ if (!p->pre_handler || !p->pre_handler(p, regs)) {
+ regs->iaoq[0] = ip + 4;
+ regs->iaoq[1] = ip + 8;
+
+ if (unlikely(p->post_handler)) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ p->post_handler(p, regs, 0);
+ }
+ }
+ __this_cpu_write(current_kprobe, NULL);
+}
+NOKPROBE_SYMBOL(kprobe_ftrace_handler);
+
+int arch_prepare_kprobe_ftrace(struct kprobe *p)
+{
+ p->ainsn.insn = NULL;
+ return 0;
+}
+#endif
--
2.20.1
next prev parent reply other threads:[~2019-07-23 20:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 20:37 [PATCH 0/4] Add support for kprobes on ftrace Sven Schnelle
2019-07-23 20:37 ` [PATCH 1/4] parisc/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support Sven Schnelle
2019-07-23 20:37 ` Sven Schnelle [this message]
2019-07-23 20:37 ` [PATCH 3/4] parisc: Update feature list Sven Schnelle
2019-07-23 20:37 ` [PATCH 4/4] parisc: fix race condition in patching code Sven Schnelle
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190723203754.7126-3-svens@stackframe.org \
--to=svens@stackframe.org \
--cc=deller@gmx.de \
--cc=linux-parisc@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.