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Groups > linux.kernel > #1738573
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.18 13/42] powerpc: Fix DAR reporting when alignment handler faults |
| Date | 2017-09-24 23:40 +0200 |
| Message-ID | <utmN5-5vy-31@gated-at.bofh.it> (permalink) |
| References | <utlHj-4Np-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Ellerman <mpe@ellerman.id.au>
commit f9effe925039cf54489b5c04e0d40073bb3a123d upstream.
Anton noticed that if we fault part way through emulating an unaligned
instruction, we don't update the DAR to reflect that.
The DAR value is eventually reported back to userspace as the address
in the SEGV signal, and if userspace is using that value to demand
fault then it can be confused by us not setting the value correctly.
This patch is ugly as hell, but is intended to be the minimal fix and
back ports easily.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/align.c | 119 +++++++++++++++++++++++++++-----------------
1 file changed, 74 insertions(+), 45 deletions(-)
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -236,6 +236,28 @@ static int emulate_dcbz(struct pt_regs *
#define SWIZ_PTR(p) ((unsigned char __user *)((p) ^ swiz))
+#define __get_user_or_set_dar(_regs, _dest, _addr) \
+ ({ \
+ int rc = 0; \
+ typeof(_addr) __addr = (_addr); \
+ if (__get_user_inatomic(_dest, __addr)) { \
+ _regs->dar = (unsigned long)__addr; \
+ rc = -EFAULT; \
+ } \
+ rc; \
+ })
+
+#define __put_user_or_set_dar(_regs, _src, _addr) \
+ ({ \
+ int rc = 0; \
+ typeof(_addr) __addr = (_addr); \
+ if (__put_user_inatomic(_src, __addr)) { \
+ _regs->dar = (unsigned long)__addr; \
+ rc = -EFAULT; \
+ } \
+ rc; \
+ })
+
static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr,
unsigned int reg, unsigned int nb,
unsigned int flags, unsigned int instr,
@@ -264,9 +286,10 @@ static int emulate_multiple(struct pt_re
} else {
unsigned long pc = regs->nip ^ (swiz & 4);
- if (__get_user_inatomic(instr,
- (unsigned int __user *)pc))
+ if (__get_user_or_set_dar(regs, instr,
+ (unsigned int __user *)pc))
return -EFAULT;
+
if (swiz == 0 && (flags & SW))
instr = cpu_to_le32(instr);
nb = (instr >> 11) & 0x1f;
@@ -310,31 +333,31 @@ static int emulate_multiple(struct pt_re
((nb0 + 3) / 4) * sizeof(unsigned long));
for (i = 0; i < nb; ++i, ++p)
- if (__get_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
- SWIZ_PTR(p)))
+ if (__get_user_or_set_dar(regs, REG_BYTE(rptr, i ^ bswiz),
+ SWIZ_PTR(p)))
return -EFAULT;
if (nb0 > 0) {
rptr = ®s->gpr[0];
addr += nb;
for (i = 0; i < nb0; ++i, ++p)
- if (__get_user_inatomic(REG_BYTE(rptr,
- i ^ bswiz),
- SWIZ_PTR(p)))
+ if (__get_user_or_set_dar(regs,
+ REG_BYTE(rptr, i ^ bswiz),
+ SWIZ_PTR(p)))
return -EFAULT;
}
} else {
for (i = 0; i < nb; ++i, ++p)
- if (__put_user_inatomic(REG_BYTE(rptr, i ^ bswiz),
- SWIZ_PTR(p)))
+ if (__put_user_or_set_dar(regs, REG_BYTE(rptr, i ^ bswiz),
+ SWIZ_PTR(p)))
return -EFAULT;
if (nb0 > 0) {
rptr = ®s->gpr[0];
addr += nb;
for (i = 0; i < nb0; ++i, ++p)
- if (__put_user_inatomic(REG_BYTE(rptr,
- i ^ bswiz),
- SWIZ_PTR(p)))
+ if (__put_user_or_set_dar(regs,
+ REG_BYTE(rptr, i ^ bswiz),
+ SWIZ_PTR(p)))
return -EFAULT;
}
}
@@ -346,29 +369,32 @@ static int emulate_multiple(struct pt_re
* Only POWER6 has these instructions, and it does true little-endian,
* so we don't need the address swizzling.
*/
-static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg,
- unsigned int flags)
+static int emulate_fp_pair(struct pt_regs *regs, unsigned char __user *addr,
+ unsigned int reg, unsigned int flags)
{
char *ptr0 = (char *) ¤t->thread.TS_FPR(reg);
char *ptr1 = (char *) ¤t->thread.TS_FPR(reg+1);
- int i, ret, sw = 0;
+ int i, sw = 0;
if (reg & 1)
return 0; /* invalid form: FRS/FRT must be even */
if (flags & SW)
sw = 7;
- ret = 0;
+
for (i = 0; i < 8; ++i) {
if (!(flags & ST)) {
- ret |= __get_user(ptr0[i^sw], addr + i);
- ret |= __get_user(ptr1[i^sw], addr + i + 8);
+ if (__get_user_or_set_dar(regs, ptr0[i^sw], addr + i))
+ return -EFAULT;
+ if (__get_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
+ return -EFAULT;
} else {
- ret |= __put_user(ptr0[i^sw], addr + i);
- ret |= __put_user(ptr1[i^sw], addr + i + 8);
+ if (__put_user_or_set_dar(regs, ptr0[i^sw], addr + i))
+ return -EFAULT;
+ if (__put_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
+ return -EFAULT;
}
}
- if (ret)
- return -EFAULT;
+
return 1; /* exception handled and fixed up */
}
@@ -378,24 +404,27 @@ static int emulate_lq_stq(struct pt_regs
{
char *ptr0 = (char *)®s->gpr[reg];
char *ptr1 = (char *)®s->gpr[reg+1];
- int i, ret, sw = 0;
+ int i, sw = 0;
if (reg & 1)
return 0; /* invalid form: GPR must be even */
if (flags & SW)
sw = 7;
- ret = 0;
+
for (i = 0; i < 8; ++i) {
if (!(flags & ST)) {
- ret |= __get_user(ptr0[i^sw], addr + i);
- ret |= __get_user(ptr1[i^sw], addr + i + 8);
+ if (__get_user_or_set_dar(regs, ptr0[i^sw], addr + i))
+ return -EFAULT;
+ if (__get_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
+ return -EFAULT;
} else {
- ret |= __put_user(ptr0[i^sw], addr + i);
- ret |= __put_user(ptr1[i^sw], addr + i + 8);
+ if (__put_user_or_set_dar(regs, ptr0[i^sw], addr + i))
+ return -EFAULT;
+ if (__put_user_or_set_dar(regs, ptr1[i^sw], addr + i + 8))
+ return -EFAULT;
}
}
- if (ret)
- return -EFAULT;
+
return 1; /* exception handled and fixed up */
}
#endif /* CONFIG_PPC64 */
@@ -688,9 +717,14 @@ static int emulate_vsx(unsigned char __u
for (j = 0; j < length; j += elsize) {
for (i = 0; i < elsize; ++i) {
if (flags & ST)
- ret |= __put_user(ptr[i^sw], addr + i);
+ ret = __put_user_or_set_dar(regs, ptr[i^sw],
+ addr + i);
else
- ret |= __get_user(ptr[i^sw], addr + i);
+ ret = __get_user_or_set_dar(regs, ptr[i^sw],
+ addr + i);
+
+ if (ret)
+ return ret;
}
ptr += elsize;
#ifdef __LITTLE_ENDIAN__
@@ -740,7 +774,7 @@ int fix_alignment(struct pt_regs *regs)
unsigned int dsisr;
unsigned char __user *addr;
unsigned long p, swiz;
- int ret, i;
+ int i;
union data {
u64 ll;
double dd;
@@ -923,7 +957,7 @@ int fix_alignment(struct pt_regs *regs)
if (flags & F) {
/* Special case for 16-byte FP loads and stores */
PPC_WARN_ALIGNMENT(fp_pair, regs);
- return emulate_fp_pair(addr, reg, flags);
+ return emulate_fp_pair(regs, addr, reg, flags);
} else {
#ifdef CONFIG_PPC64
/* Special case for 16-byte loads and stores */
@@ -953,15 +987,12 @@ int fix_alignment(struct pt_regs *regs)
}
data.ll = 0;
- ret = 0;
p = (unsigned long)addr;
for (i = 0; i < nb; i++)
- ret |= __get_user_inatomic(data.v[start + i],
- SWIZ_PTR(p++));
-
- if (unlikely(ret))
- return -EFAULT;
+ if (__get_user_or_set_dar(regs, data.v[start + i],
+ SWIZ_PTR(p++)))
+ return -EFAULT;
} else if (flags & F) {
data.ll = current->thread.TS_FPR(reg);
@@ -1031,15 +1062,13 @@ int fix_alignment(struct pt_regs *regs)
break;
}
- ret = 0;
p = (unsigned long)addr;
for (i = 0; i < nb; i++)
- ret |= __put_user_inatomic(data.v[start + i],
- SWIZ_PTR(p++));
+ if (__put_user_or_set_dar(regs, data.v[start + i],
+ SWIZ_PTR(p++)))
+ return -EFAULT;
- if (unlikely(ret))
- return -EFAULT;
} else if (flags & F)
current->thread.TS_FPR(reg) = data.ll;
else
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[PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 11/42] [PATCH - RESEND] crypto: AF_ALG - remove SGL terminator indicator when chaining Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 25/42] scsi: sg: use standard lists for sg_requests Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 03/42] Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 42/42] mac80211: flush hw_roc_start work before cancelling the ROC Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 05/42] ipv6: fix memory leak with multiple tables during netns destruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 27/42] scsi: sg: factor out sg_fill_request_table() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 12/42] ext4: fix incorrect quotaoff if the quota feature is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 01/42] ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 21/42] scsi: zfcp: fix payload with full FCP_RSP IU in SCSI trace records Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 29/42] scsi: qla2xxx: Fix an integer overflow in sysfs code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 08/42] [PATCH] Revert "usb: musb: fix tx fifo flush handling again" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 16/42] skd: Avoid that module unloading triggers a use-after-free Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:30 +0200
[PATCH 3.18 30/42] ftrace: Fix selftest goto location on error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 07/42] f2fs: check hot_data for roll-forward recovery Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 37/42] bcache: Fix leak of bdev reference Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 40/42] bcache: fix for gc and write-back race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 39/42] bcache: Correct return value for sysfs attach errors Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 41/42] bcache: fix bch_hprint crash and improve output Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 33/42] PCI: shpchp: Enable bridge bus mastering if MSI is enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 06/42] ipv6: fix typo in fib6_net_exit() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 31/42] tracing: Apply trace_clock changes to instance max buffer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 38/42] bcache: correct cache_dirty_target in __update_writeback_rate() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 32/42] ARC: Re-enable MMU upon Machine Check exception Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 28/42] scsi: sg: fixup infoleak when using SG_GET_REQUEST_TABLE Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 34/42] media: v4l2-compat-ioctl32: Fix timespec conversion Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 04/42] tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 35/42] media: uvcvideo: Prevent heap overflow when accessing mapped controls Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 22:40 +0200
[PATCH 3.18 24/42] scsi: sg: remove save_scat_len Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 14/42] block: Relax a check in blk_start_queue() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 18/42] scsi: zfcp: fix queuecommand for scsi_eh commands when DIX enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 22/42] scsi: zfcp: trace HBA FSF response by default on dismiss or timedout late response Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 26/42] scsi: sg: off by one in sg_ioctl() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 23/42] scsi: zfcp: trace high part of "new" 64 bit SCSI LUN Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 02/42] qlge: avoid memcpy buffer overflow Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
[PATCH 3.18 13/42] powerpc: Fix DAR reporting when alignment handler faults Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-24 23:40 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Guenter Roeck <linux@roeck-us.net> - 2017-09-25 03:10 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-25 08:40 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Guenter Roeck <linux@roeck-us.net> - 2017-09-25 13:10 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-25 14:30 +0200
Re: [PATCH 3.18 00/42] 3.18.72-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-09-26 01:20 +0200
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