From: Guenter Roeck <linux@roeck-us.net>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Guenter Roeck <linux@roeck-us.net>,
Oliver O'Halloran <oohall@gmail.com>,
Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH] powerpc/chrp: Revert "Move PHB discovery" and "Make hydra_init() static"
Date: Fri, 16 Jul 2021 15:11:59 -0700 [thread overview]
Message-ID: <20210716221159.3587039-1-linux@roeck-us.net> (raw)
This patch reverts commit 407d418f2fd4 ("powerpc/chrp: Move PHB
discovery") and commit 9634afa67bfd ("powerpc/chrp: Make hydra_init()
static").
Running the upstream kernel on Qemu's brand new "pegasos2" emulation
results in a variety of backtraces such as
Kernel attempted to write user page (a1) - exploit attempt? (uid: 0)
------------[ cut here ]------------
Bug: Write fault blocked by KUAP!
WARNING: CPU: 0 PID: 0 at arch/powerpc/mm/fault.c:230 do_page_fault+0x4f4/0x920
CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.2 #40
NIP: c0021824 LR: c0021824 CTR: 00000000
REGS: c1085d50 TRAP: 0700 Not tainted (5.13.2)
MSR: 00021032 <ME,IR,DR,RI> CR: 24042254 XER: 00000000
GPR00: c0021824 c1085e10 c0f8c520 00000021 3fffefff c1085c60 c1085c58 00000000
GPR08: 00001032 00000000 00000000 c0ffb3ec 44042254 00000000 00000000 00000004
GPR16: 00000000 ffffffff 000000c4 000000d0 0188c6e0 01006000 00000001 40b14000
GPR24: c0ec000c 00000300 02000000 00000000 42000000 000000a1 00000000 c1085e60
NIP [c0021824] do_page_fault+0x4f4/0x920
LR [c0021824] do_page_fault+0x4f4/0x920
Call Trace:
[c1085e10] [c0021824] do_page_fault+0x4f4/0x920 (unreliable)
[c1085e50] [c0004254] DataAccess_virt+0xd4/0xe4
and the system fails to boot. Bisect points to commit 407d418f2fd4
("powerpc/chrp: Move PHB discovery"). Reverting this patch together with
commit 9634afa67bfd ("powerpc/chrp: Make hydra_init() static") fixes
the problem.
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 407d418f2fd4 ("powerpc/chrp: Move PHB discovery")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
arch/powerpc/include/asm/hydra.h | 2 ++
arch/powerpc/platforms/chrp/pci.c | 11 ++---------
arch/powerpc/platforms/chrp/setup.c | 12 +++++++++++-
3 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/include/asm/hydra.h b/arch/powerpc/include/asm/hydra.h
index d024447283a0..ae02eb53d6ef 100644
--- a/arch/powerpc/include/asm/hydra.h
+++ b/arch/powerpc/include/asm/hydra.h
@@ -94,6 +94,8 @@ extern volatile struct Hydra __iomem *Hydra;
#define HYDRA_INT_EXT7 18 /* Power Off Request */
#define HYDRA_INT_SPARE 19
+extern int hydra_init(void);
+
#endif /* __KERNEL__ */
#endif /* _ASMPPC_HYDRA_H */
diff --git a/arch/powerpc/platforms/chrp/pci.c b/arch/powerpc/platforms/chrp/pci.c
index 76e6256cb0a7..b2c2bf35b76c 100644
--- a/arch/powerpc/platforms/chrp/pci.c
+++ b/arch/powerpc/platforms/chrp/pci.c
@@ -131,7 +131,8 @@ static struct pci_ops rtas_pci_ops =
volatile struct Hydra __iomem *Hydra = NULL;
-static int __init hydra_init(void)
+int __init
+hydra_init(void)
{
struct device_node *np;
struct resource r;
@@ -313,14 +314,6 @@ chrp_find_bridges(void)
}
}
of_node_put(root);
-
- /*
- * "Temporary" fixes for PCI devices.
- * -- Geert
- */
- hydra_init(); /* Mac I/O */
-
- pci_create_OF_bus_map();
}
/* SL82C105 IDE Control/Status Register */
diff --git a/arch/powerpc/platforms/chrp/setup.c b/arch/powerpc/platforms/chrp/setup.c
index 3cfc382841e5..c45435aa5e36 100644
--- a/arch/powerpc/platforms/chrp/setup.c
+++ b/arch/powerpc/platforms/chrp/setup.c
@@ -334,11 +334,22 @@ static void __init chrp_setup_arch(void)
/* On pegasos, enable the L2 cache if not already done by OF */
pegasos_set_l2cr();
+ /* Lookup PCI host bridges */
+ chrp_find_bridges();
+
+ /*
+ * Temporary fixes for PCI devices.
+ * -- Geert
+ */
+ hydra_init(); /* Mac I/O */
+
/*
* Fix the Super I/O configuration
*/
sio_init();
+ pci_create_OF_bus_map();
+
/*
* Print the banner, then scroll down so boot progress
* can be printed. -- Cort
@@ -571,7 +582,6 @@ define_machine(chrp) {
.name = "CHRP",
.probe = chrp_probe,
.setup_arch = chrp_setup_arch,
- .discover_phbs = chrp_find_bridges,
.init = chrp_init2,
.show_cpuinfo = chrp_show_cpuinfo,
.init_IRQ = chrp_init_IRQ,
--
2.25.1
next reply other threads:[~2021-07-16 22:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 22:11 Guenter Roeck [this message]
2021-07-17 15:54 ` [PATCH] powerpc/chrp: Revert "Move PHB discovery" and "Make hydra_init() static" Oliver O'Halloran
2021-07-17 16:14 ` Guenter Roeck
2021-07-18 16:13 ` Oliver O'Halloran
2021-07-17 15:57 ` Christophe Leroy
2021-07-17 16:01 ` Christophe Leroy
2021-07-17 16:23 ` Guenter Roeck
2021-07-18 16:09 ` Oliver O'Halloran
2022-09-08 6:23 ` Christophe Leroy
2022-09-08 13:47 ` Guenter Roeck
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