4.19-stable review patch. If anyone has any objections, please let me know.
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From: Christophe Leroy christophe.leroy@c-s.fr
[ Upstream commit 0261a508c9fcb33e60f09cac42032f85c31e2039 ]
This patch creates a debugfs file to see content of segment registers
# cat /sys/kernel/debug/segment_registers ---[ User Segments ]--- 0x00000000-0x0fffffff Kern key 1 User key 1 VSID 0xade2b0 0x10000000-0x1fffffff Kern key 1 User key 1 VSID 0xade3c1 0x20000000-0x2fffffff Kern key 1 User key 1 VSID 0xade4d2 0x30000000-0x3fffffff Kern key 1 User key 1 VSID 0xade5e3 0x40000000-0x4fffffff Kern key 1 User key 1 VSID 0xade6f4 0x50000000-0x5fffffff Kern key 1 User key 1 VSID 0xade805 0x60000000-0x6fffffff Kern key 1 User key 1 VSID 0xade916 0x70000000-0x7fffffff Kern key 1 User key 1 VSID 0xadea27 0x80000000-0x8fffffff Kern key 1 User key 1 VSID 0xadeb38 0x90000000-0x9fffffff Kern key 1 User key 1 VSID 0xadec49 0xa0000000-0xafffffff Kern key 1 User key 1 VSID 0xaded5a 0xb0000000-0xbfffffff Kern key 1 User key 1 VSID 0xadee6b
---[ Kernel Segments ]--- 0xc0000000-0xcfffffff Kern key 0 User key 1 VSID 0x000ccc 0xd0000000-0xdfffffff Kern key 0 User key 1 VSID 0x000ddd 0xe0000000-0xefffffff Kern key 0 User key 1 VSID 0x000eee 0xf0000000-0xffffffff Kern key 0 User key 1 VSID 0x000fff
Signed-off-by: Christophe Leroy christophe.leroy@c-s.fr [mpe: Move it under /sys/kernel/debug/powerpc, make sr_init() __init] Signed-off-by: Michael Ellerman mpe@ellerman.id.au Stable-dep-of: 66b2ca086210 ("powerpc/64s/radix: Fix soft dirty tracking") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/mm/Makefile | 2 +- arch/powerpc/mm/dump_sr.c | 64 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/mm/dump_sr.c
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index 3c844bdd16c4e..d2784730c0e5d 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -47,7 +47,7 @@ ifdef CONFIG_PPC_PTDUMP obj-$(CONFIG_4xx) += dump_linuxpagetables-generic.o obj-$(CONFIG_PPC_8xx) += dump_linuxpagetables-8xx.o obj-$(CONFIG_PPC_BOOK3E_MMU) += dump_linuxpagetables-generic.o -obj-$(CONFIG_PPC_BOOK3S_32) += dump_linuxpagetables-generic.o +obj-$(CONFIG_PPC_BOOK3S_32) += dump_linuxpagetables-generic.o dump_sr.o obj-$(CONFIG_PPC_BOOK3S_64) += dump_linuxpagetables-book3s64.o endif obj-$(CONFIG_PPC_HTDUMP) += dump_hashpagetable.o diff --git a/arch/powerpc/mm/dump_sr.c b/arch/powerpc/mm/dump_sr.c new file mode 100644 index 0000000000000..501843664bb91 --- /dev/null +++ b/arch/powerpc/mm/dump_sr.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2018, Christophe Leroy CS S.I. + * christophe.leroy@c-s.fr + * + * This dumps the content of Segment Registers + */ + +#include <asm/debugfs.h> + +static void seg_show(struct seq_file *m, int i) +{ + u32 val = mfsrin(i << 28); + + seq_printf(m, "0x%01x0000000-0x%01xfffffff ", i, i); + seq_printf(m, "Kern key %d ", (val >> 30) & 1); + seq_printf(m, "User key %d ", (val >> 29) & 1); + if (val & 0x80000000) { + seq_printf(m, "Device 0x%03x", (val >> 20) & 0x1ff); + seq_printf(m, "-0x%05x", val & 0xfffff); + } else { + if (val & 0x10000000) + seq_puts(m, "No Exec "); + seq_printf(m, "VSID 0x%06x", val & 0xffffff); + } + seq_puts(m, "\n"); +} + +static int sr_show(struct seq_file *m, void *v) +{ + int i; + + seq_puts(m, "---[ User Segments ]---\n"); + for (i = 0; i < TASK_SIZE >> 28; i++) + seg_show(m, i); + + seq_puts(m, "\n---[ Kernel Segments ]---\n"); + for (; i < 16; i++) + seg_show(m, i); + + return 0; +} + +static int sr_open(struct inode *inode, struct file *file) +{ + return single_open(file, sr_show, NULL); +} + +static const struct file_operations sr_fops = { + .open = sr_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init sr_init(void) +{ + struct dentry *debugfs_file; + + debugfs_file = debugfs_create_file("segment_registers", 0400, + powerpc_debugfs_root, NULL, &sr_fops); + return debugfs_file ? 0 : -ENOMEM; +} +device_initcall(sr_init);