From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
naveen.n.rao@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 10/12] powerpc/entry32: Blacklist exception entry points for kprobe.
Date: Tue, 31 Mar 2020 16:03:45 +0000 (UTC) [thread overview]
Message-ID: <f61ac599855e674ebb592464d0ea32a3ba9c6644.1585670437.git.christophe.leroy@c-s.fr> (raw)
In-Reply-To: <1ae02b6637b87fc5aaa1d5012c3e2cb30e62b4a3.1585670437.git.christophe.leroy@c-s.fr>
kprobe does not handle events happening in real mode.
As exception entry points are running with MMU disabled,
blacklist them.
The handling of TLF_NAPPING and TLF_SLEEPING is moved before the
CONFIG_TRACE_IRQFLAGS which contains 'reenable_mmu' because from there
kprobe will be possible as the kernel will run with MMU enabled.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
v2: Moved TLF_NAPPING and TLF_SLEEPING handling
---
arch/powerpc/kernel/entry_32.S | 37 ++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 94f78c03cb79..215aa3a6d4f7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -51,6 +51,7 @@ mcheck_transfer_to_handler:
mfspr r0,SPRN_DSRR1
stw r0,_DSRR1(r11)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(mcheck_transfer_to_handler)
.globl debug_transfer_to_handler
debug_transfer_to_handler:
@@ -59,6 +60,7 @@ debug_transfer_to_handler:
mfspr r0,SPRN_CSRR1
stw r0,_CSRR1(r11)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(debug_transfer_to_handler)
.globl crit_transfer_to_handler
crit_transfer_to_handler:
@@ -94,6 +96,7 @@ crit_transfer_to_handler:
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
#ifdef CONFIG_40x
@@ -115,6 +118,7 @@ crit_transfer_to_handler:
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
/*
@@ -127,6 +131,7 @@ crit_transfer_to_handler:
.globl transfer_to_handler_full
transfer_to_handler_full:
SAVE_NVGPRS(r11)
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler_full)
/* fall through */
.globl transfer_to_handler
@@ -227,6 +232,23 @@ transfer_to_handler_cont:
SYNC
RFI /* jump to handler, enable MMU */
+#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
+4: rlwinm r12,r12,0,~_TLF_NAPPING
+ stw r12,TI_LOCAL_FLAGS(r2)
+ b power_save_ppc32_restore
+
+7: rlwinm r12,r12,0,~_TLF_SLEEPING
+ stw r12,TI_LOCAL_FLAGS(r2)
+ lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
+ rlwinm r9,r9,0,~MSR_EE
+ lwz r12,_LINK(r11) /* and return to address in LR */
+ kuap_restore r11, r2, r3, r4, r5
+ lwz r2, GPR2(r11)
+ b fast_exception_return
+#endif
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler)
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
+
#ifdef CONFIG_TRACE_IRQFLAGS
1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
* keep interrupts disabled at this point otherwise we might risk
@@ -272,21 +294,6 @@ reenable_mmu:
bctr /* jump to handler */
#endif /* CONFIG_TRACE_IRQFLAGS */
-#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
-4: rlwinm r12,r12,0,~_TLF_NAPPING
- stw r12,TI_LOCAL_FLAGS(r2)
- b power_save_ppc32_restore
-
-7: rlwinm r12,r12,0,~_TLF_SLEEPING
- stw r12,TI_LOCAL_FLAGS(r2)
- lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
- rlwinm r9,r9,0,~MSR_EE
- lwz r12,_LINK(r11) /* and return to address in LR */
- kuap_restore r11, r2, r3, r4, r5
- lwz r2, GPR2(r11)
- b fast_exception_return
-#endif
-
#ifndef CONFIG_VMAP_STACK
/*
* On kernel stack overflow, load up an initial stack pointer
--
2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
naveen.n.rao@linux.vnet.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 10/12] powerpc/entry32: Blacklist exception entry points for kprobe.
Date: Tue, 31 Mar 2020 16:03:45 +0000 (UTC) [thread overview]
Message-ID: <f61ac599855e674ebb592464d0ea32a3ba9c6644.1585670437.git.christophe.leroy@c-s.fr> (raw)
In-Reply-To: <1ae02b6637b87fc5aaa1d5012c3e2cb30e62b4a3.1585670437.git.christophe.leroy@c-s.fr>
kprobe does not handle events happening in real mode.
As exception entry points are running with MMU disabled,
blacklist them.
The handling of TLF_NAPPING and TLF_SLEEPING is moved before the
CONFIG_TRACE_IRQFLAGS which contains 'reenable_mmu' because from there
kprobe will be possible as the kernel will run with MMU enabled.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
v2: Moved TLF_NAPPING and TLF_SLEEPING handling
---
arch/powerpc/kernel/entry_32.S | 37 ++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 94f78c03cb79..215aa3a6d4f7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -51,6 +51,7 @@ mcheck_transfer_to_handler:
mfspr r0,SPRN_DSRR1
stw r0,_DSRR1(r11)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(mcheck_transfer_to_handler)
.globl debug_transfer_to_handler
debug_transfer_to_handler:
@@ -59,6 +60,7 @@ debug_transfer_to_handler:
mfspr r0,SPRN_CSRR1
stw r0,_CSRR1(r11)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(debug_transfer_to_handler)
.globl crit_transfer_to_handler
crit_transfer_to_handler:
@@ -94,6 +96,7 @@ crit_transfer_to_handler:
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
#ifdef CONFIG_40x
@@ -115,6 +118,7 @@ crit_transfer_to_handler:
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
+_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#endif
/*
@@ -127,6 +131,7 @@ crit_transfer_to_handler:
.globl transfer_to_handler_full
transfer_to_handler_full:
SAVE_NVGPRS(r11)
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler_full)
/* fall through */
.globl transfer_to_handler
@@ -227,6 +232,23 @@ transfer_to_handler_cont:
SYNC
RFI /* jump to handler, enable MMU */
+#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
+4: rlwinm r12,r12,0,~_TLF_NAPPING
+ stw r12,TI_LOCAL_FLAGS(r2)
+ b power_save_ppc32_restore
+
+7: rlwinm r12,r12,0,~_TLF_SLEEPING
+ stw r12,TI_LOCAL_FLAGS(r2)
+ lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
+ rlwinm r9,r9,0,~MSR_EE
+ lwz r12,_LINK(r11) /* and return to address in LR */
+ kuap_restore r11, r2, r3, r4, r5
+ lwz r2, GPR2(r11)
+ b fast_exception_return
+#endif
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler)
+_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
+
#ifdef CONFIG_TRACE_IRQFLAGS
1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
* keep interrupts disabled at this point otherwise we might risk
@@ -272,21 +294,6 @@ reenable_mmu:
bctr /* jump to handler */
#endif /* CONFIG_TRACE_IRQFLAGS */
-#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
-4: rlwinm r12,r12,0,~_TLF_NAPPING
- stw r12,TI_LOCAL_FLAGS(r2)
- b power_save_ppc32_restore
-
-7: rlwinm r12,r12,0,~_TLF_SLEEPING
- stw r12,TI_LOCAL_FLAGS(r2)
- lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
- rlwinm r9,r9,0,~MSR_EE
- lwz r12,_LINK(r11) /* and return to address in LR */
- kuap_restore r11, r2, r3, r4, r5
- lwz r2, GPR2(r11)
- b fast_exception_return
-#endif
-
#ifndef CONFIG_VMAP_STACK
/*
* On kernel stack overflow, load up an initial stack pointer
--
2.25.0
next prev parent reply other threads:[~2020-03-31 16:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-31 16:03 [PATCH v2 01/12] powerpc/52xx: Blacklist functions running with MMU disabled for kprobe Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 02/12] powerpc/82xx: Blacklist pq2_restart() " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 03/12] powerpc/83xx: Blacklist mpc83xx_deep_resume() " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 04/12] powerpc/powermac: Blacklist functions running with MMU disabled " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 05/12] powerpc/mem: Blacklist flush_dcache_icache_phys() " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 06/12] powerpc/32s: Make local symbols non visible in hash_low Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 07/12] powerpc/32s: Blacklist functions running with MMU disabled for kprobe Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 08/12] powerpc/rtas: Remove machine_check_in_rtas() Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 09/12] powerpc/32: Blacklist functions running with MMU disabled for kprobe Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy [this message]
2020-03-31 16:03 ` [PATCH v2 10/12] powerpc/entry32: Blacklist exception entry points " Christophe Leroy
2020-03-31 17:05 ` Naveen N. Rao
2020-03-31 17:05 ` Naveen N. Rao
2020-03-31 16:03 ` [PATCH v2 11/12] powerpc/entry32: Blacklist syscall exit " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-03-31 16:03 ` [PATCH v2 12/12] powerpc/entry32: Blacklist exception " Christophe Leroy
2020-03-31 16:03 ` Christophe Leroy
2020-06-09 5:28 ` [PATCH v2 01/12] powerpc/52xx: Blacklist functions running with MMU disabled " Michael Ellerman
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=f61ac599855e674ebb592464d0ea32a3ba9c6644.1585670437.git.christophe.leroy@c-s.fr \
--to=christophe.leroy@c-s.fr \
--cc=benh@kernel.crashing.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=naveen.n.rao@linux.vnet.ibm.com \
--cc=paulus@samba.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.