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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-09-23 11:06:30 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-09-24 11:07:00 +0100
commit274e91b81ed22957b510ad2988359584eea95dae (patch)
treec49fc7443c419eb89925db93503db21f8d09a2b7 /arch/arm/mm
parent208473c1f3ac3eccec097021eec3890f5e20fcc7 (diff)
downloadlinux-linaro-stable-274e91b81ed22957b510ad2988359584eea95dae.tar.gz
ARM: alignment: fix alignment handling for uaccess changes
Jonathan Liu reports that the recent addition of CPU_SW_DOMAIN_PAN causes wpa_supplicant to die due to the following kernel oops: Unhandled fault: page domain fault (0x81b) at 0x001017a2 pgd = ee1b8000 [001017a2] *pgd=6ebee831, *pte=6c35475f, *ppte=6c354c7f Internal error: : 81b [#1] SMP ARM Modules linked in: rt2800usb rt2x00usb rt2800librt2x00lib crc_ccitt mac80211 CPU: 1 PID: 202 Comm: wpa_supplicant Not tainted 4.3.0-rc2 #1 Hardware name: Allwinner sun7i (A20) Family task: ec872f80 ti: ee364000 task.ti: ee364000 PC is at do_alignment_ldmstm+0x1d4/0x238 LR is at 0x0 pc : [<c001d1d8>] lr : [<00000000>] psr: 600c0113 sp : ee365e18 ip : 00000000 fp : 00000002 r10: 001017a2 r9 : 00000002 r8 : 001017aa r7 : ee365fb0 r6 : e8820018 r5 : 001017a2 r4 : 00000003 r3 : d49e30e0 r2 : 00000000 r1 : ee365fbc r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none[ 34.393106] Control: 10c5387d Table: 6e1b806a DAC: 00000051 Process wpa_supplicant (pid: 202, stack limit = 0xee364210) Stack: (0xee365e18 to 0xee366000) ... [<c001d1d8>] (do_alignment_ldmstm) from [<c001d510>] (do_alignment+0x1f0/0x904) [<c001d510>] (do_alignment) from [<c00092a0>] (do_DataAbort+0x38/0xb4) [<c00092a0>] (do_DataAbort) from [<c0013d7c>] (__dabt_usr+0x3c/0x40) Exception stack(0xee365fb0 to 0xee365ff8) 5fa0: 00000000 56c728c0 001017a2 d49e30e0 5fc0: 775448d2 597d4e74 00200800 7a9e1625 00802001 00000021 b6deec84 00000100 5fe0: 08020200 be9f4f20 0c0b0d0a b6d9b3e0 600c0010 ffffffff Code: e1a0a005 e1a0000c 1affffe8 e5913000 (e4ea3001) ---[ end trace 0acd3882fcfdf9dd ]--- This is caused by the alignment handler not being fixed up for the uaccess changes, and userspace issuing an unaligned LDM instruction. So, fix the problem by adding the necessary fixups. Reported-by: Jonathan Liu <net147@gmail.com> Tested-by: Jonathan Liu <net147@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/alignment.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 9769f1eefe3b..00b7f7de28a1 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -365,15 +365,21 @@ do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *r
user:
if (LDST_L_BIT(instr)) {
unsigned long val;
+ unsigned int __ua_flags = uaccess_save_and_enable();
+
get16t_unaligned_check(val, addr);
+ uaccess_restore(__ua_flags);
/* signed half-word? */
if (instr & 0x40)
val = (signed long)((signed short) val);
regs->uregs[rd] = val;
- } else
+ } else {
+ unsigned int __ua_flags = uaccess_save_and_enable();
put16t_unaligned_check(regs->uregs[rd], addr);
+ uaccess_restore(__ua_flags);
+ }
return TYPE_LDST;
@@ -420,14 +426,21 @@ do_alignment_ldrdstrd(unsigned long addr, unsigned long instr,
user:
if (load) {
- unsigned long val;
+ unsigned long val, val2;
+ unsigned int __ua_flags = uaccess_save_and_enable();
+
get32t_unaligned_check(val, addr);
+ get32t_unaligned_check(val2, addr + 4);
+
+ uaccess_restore(__ua_flags);
+
regs->uregs[rd] = val;
- get32t_unaligned_check(val, addr + 4);
- regs->uregs[rd2] = val;
+ regs->uregs[rd2] = val2;
} else {
+ unsigned int __ua_flags = uaccess_save_and_enable();
put32t_unaligned_check(regs->uregs[rd], addr);
put32t_unaligned_check(regs->uregs[rd2], addr + 4);
+ uaccess_restore(__ua_flags);
}
return TYPE_LDST;
@@ -458,10 +471,15 @@ do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *reg
trans:
if (LDST_L_BIT(instr)) {
unsigned int val;
+ unsigned int __ua_flags = uaccess_save_and_enable();
get32t_unaligned_check(val, addr);
+ uaccess_restore(__ua_flags);
regs->uregs[rd] = val;
- } else
+ } else {
+ unsigned int __ua_flags = uaccess_save_and_enable();
put32t_unaligned_check(regs->uregs[rd], addr);
+ uaccess_restore(__ua_flags);
+ }
return TYPE_LDST;
fault:
@@ -531,6 +549,7 @@ do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *reg
#endif
if (user_mode(regs)) {
+ unsigned int __ua_flags = uaccess_save_and_enable();
for (regbits = REGMASK_BITS(instr), rd = 0; regbits;
regbits >>= 1, rd += 1)
if (regbits & 1) {
@@ -542,6 +561,7 @@ do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *reg
put32t_unaligned_check(regs->uregs[rd], eaddr);
eaddr += 4;
}
+ uaccess_restore(__ua_flags);
} else {
for (regbits = REGMASK_BITS(instr), rd = 0; regbits;
regbits >>= 1, rd += 1)