| 1 | do_alignment_t32_to_handler only fixes up alignment faults for specific | 1 | do_alignment_t32_to_handler only fixes up alignment faults for specific |
|---|---|---|---|
| 2 | instructions; it returns NULL otherwise. When that's the case, signal to | 2 | instructions; it returns NULL otherwise. When that's the case, signal to |
| 3 | the caller that it needs to proceed with the regular alignment fault | 3 | the caller that it needs to proceed with the regular alignment fault |
| 4 | handling (i.e. SIGBUS). | 4 | handling (i.e. SIGBUS). Without this patch, we get: |
| 5 | |||
| 6 | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | ||
| 7 | Mem abort info: | ||
| 8 | ESR = 0x0000000086000006 | ||
| 9 | EC = 0x21: IABT (current EL), IL = 32 bits | ||
| 10 | SET = 0, FnV = 0 | ||
| 11 | EA = 0, S1PTW = 0 | ||
| 12 | FSC = 0x06: level 2 translation fault | ||
| 13 | user pgtable: 4k pages, 48-bit VAs, pgdp=00000800164aa000 | ||
| 14 | [0000000000000000] pgd=0800081fdbd22003, p4d=0800081fdbd22003, pud=08000815d51c6003, pmd=0000000000000000 | ||
| 15 | Internal error: Oops: 0000000086000006 [#1] SMP | ||
| 16 | Modules linked in: cfg80211 rfkill xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xfrm_user xfrm_algo xt_addrtype nft_compat br_netfilter veth nvme_fa> | ||
| 17 | libcrc32c crc32c_generic raid0 multipath linear dm_mod dax raid1 md_mod xhci_pci nvme xhci_hcd nvme_core t10_pi usbcore igb crc64_rocksoft crc64 crc_t10dif crct10dif_generic crct10dif_ce crct10dif_common usb_common i2c_algo_bit i2c> | ||
| 18 | CPU: 2 PID: 3932954 Comm: WPEWebProcess Not tainted 6.1.0-31-arm64 #1 Debian 6.1.128-1 | ||
| 19 | Hardware name: GIGABYTE MP32-AR1-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021 | ||
| 20 | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | ||
| 21 | pc : 0x0 | ||
| 22 | lr : do_compat_alignment_fixup+0xd8/0x3dc | ||
| 23 | sp : ffff80000f973dd0 | ||
| 24 | x29: ffff80000f973dd0 x28: ffff081b42526180 x27: 0000000000000000 | ||
| 25 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | ||
| 26 | x23: 0000000000000004 x22: 0000000000000000 x21: 0000000000000001 | ||
| 27 | x20: 00000000e8551f00 x19: ffff80000f973eb0 x18: 0000000000000000 | ||
| 28 | x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 | ||
| 29 | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 | ||
| 30 | x11: 0000000000000000 x10: 0000000000000000 x9 : ffffaebc949bc488 | ||
| 31 | x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 | ||
| 32 | x5 : 0000000000400000 x4 : 0000fffffffffffe x3 : 0000000000000000 | ||
| 33 | x2 : ffff80000f973eb0 x1 : 00000000e8551f00 x0 : 0000000000000001 | ||
| 34 | Call trace: | ||
| 35 | 0x0 | ||
| 36 | do_alignment_fault+0x40/0x50 | ||
| 37 | do_mem_abort+0x4c/0xa0 | ||
| 38 | el0_da+0x48/0xf0 | ||
| 39 | el0t_32_sync_handler+0x110/0x140 | ||
| 40 | el0t_32_sync+0x190/0x194 | ||
| 41 | Code: bad PC value | ||
| 42 | ---[ end trace 0000000000000000 ]--- | ||
| 5 | 43 | ||
| 6 | Signed-off-by: Angelos Oikonomopoulos <angelos@igalia.com> | 44 | Signed-off-by: Angelos Oikonomopoulos <angelos@igalia.com> |
| 45 | Fixes: 3fc24ef32d3b93 ("arm64: compat: Implement misalignment fixups for multiword loads") | ||
| 46 | Cc: stable@vger.kernel.org | ||
| 7 | --- | 47 | --- |
| 8 | arch/arm64/kernel/compat_alignment.c | 4 +++- | 48 | arch/arm64/kernel/compat_alignment.c | 2 ++ |
| 9 | 1 file changed, 3 insertions(+), 1 deletion(-) | 49 | 1 file changed, 2 insertions(+) |
| 10 | 50 | ||
| 11 | diff --git a/arch/arm64/kernel/compat_alignment.c b/arch/arm64/kernel/compat_alignment.c | 51 | diff --git a/arch/arm64/kernel/compat_alignment.c b/arch/arm64/kernel/compat_alignment.c |
| 12 | index XXXXXXX..XXXXXXX 100644 | 52 | index XXXXXXX..XXXXXXX 100644 |
| 13 | --- a/arch/arm64/kernel/compat_alignment.c | 53 | --- a/arch/arm64/kernel/compat_alignment.c |
| 14 | +++ b/arch/arm64/kernel/compat_alignment.c | 54 | +++ b/arch/arm64/kernel/compat_alignment.c |
| 15 | @@ -XXX,XX +XXX,XX @@ | ||
| 16 | |||
| 17 | #define REGMASK_BITS(i) (i & 0xffff) | ||
| 18 | |||
| 19 | -#define BAD_INSTR 0xdeadc0de | ||
| 20 | +#define BAD_INSTR 0xdeadc0de | ||
| 21 | |||
| 22 | /* Thumb-2 32 bit format per ARMv7 DDI0406A A6.3, either f800h,e800h,f800h */ | ||
| 23 | #define IS_T32(hi16) \ | ||
| 24 | @@ -XXX,XX +XXX,XX @@ int do_compat_alignment_fixup(unsigned long addr, struct pt_regs *regs) | 55 | @@ -XXX,XX +XXX,XX @@ int do_compat_alignment_fixup(unsigned long addr, struct pt_regs *regs) |
| 25 | return 1; | 56 | return 1; |
| 26 | } | 57 | } |
| 27 | 58 | ||
| 28 | + if (!handler) | 59 | + if (!handler) |
| 29 | + return 1; | 60 | + return 1; |
| 30 | type = handler(addr, instr, regs); | 61 | type = handler(addr, instr, regs); |
| 31 | 62 | ||
| 32 | if (type == TYPE_ERROR || type == TYPE_FAULT) | 63 | if (type == TYPE_ERROR || type == TYPE_FAULT) |
| 33 | -- | 64 | -- |
| 34 | 2.49.0 | 65 | 2.49.0 | diff view generated by jsdifflib |