kernel.git/arch/s390/boot, branch linux-5.13.y

s390/boot: fix use of expolines in the DMA code

2021-07-28T12:37:34Z

commit 463f36c76fa4ec015c640ff63ccf52e7527abee0 upstream. The DMA code section of the decompressor must be compiled with expolines if Spectre V2 mitigation has been enabled for the decompressed kernel. This is required because although the decompressor's image contains the DMA code section, it is handed over to the decompressed kernel for use. Because the DMA code is already slow w/o expolines, use expolines always regardless whether the decompressed kernel is using them or not. This simplifies the DMA code by dropping the conditional compilation of expolines. Fixes: bf72630130c2 ("s390: use proper expoline sections for .dma code") Cc: # 5.2 Signed-off-by: Alexander Egorenkov Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/mem_detect: fix tprot() program check new psw handling

2021-07-20T14:00:20Z

[ Upstream commit da9057576785aaab52e706e76c0475c85b77ec14 ] The tprot() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/mem_detect: fix diag260() program check new psw handling

2021-07-20T14:00:20Z

[ Upstream commit 86807f348f418a84970eebb8f9912a7eea16b497 ] The __diag260() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/ipl_parm: fix program check new psw handling

2021-07-20T14:00:19Z

[ Upstream commit 88c2510cecb7e2b518e3c4fdf3cf0e13ebe9377c ] The __diag308() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390: mm: Fix secure storage access exception handling

2021-07-14T15:06:13Z

commit 85b18d7b5e7ffefb2f076186511d39c4990aa005 upstream. Turns out that the bit 61 in the TEID is not always 1 and if that's the case the address space ID and the address are unpredictable. Without an address and its address space ID we can't export memory and hence we can only send a SIGSEGV to the process or panic the kernel depending on who caused the exception. Unfortunately bit 61 is only reliable if we have the "misc" UV feature bit. Signed-off-by: Janosch Frank Reviewed-by: Christian Borntraeger Fixes: 084ea4d611a3d ("s390/mm: add (non)secure page access exceptions handlers") Cc: stable@vger.kernel.org Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390: uv: Fix sysfs max number of VCPUs reporting

2021-01-27T12:00:04Z

The number reported by the query is N-1 and I think people reading the sysfs file would expect N instead. For users creating VMs there's no actual difference because KVM's limit is currently below the UV's limit. Signed-off-by: Janosch Frank Fixes: a0f60f8431999 ("s390/protvirt: Add sysfs firmware interface for Ultravisor information") Cc: stable@vger.kernel.org Reviewed-by: Claudio Imbrenda Acked-by: Cornelia Huck Signed-off-by: Vasily Gorbik

kasan, x86, s390: update undef CONFIG_KASAN

2020-12-22T20:55:08Z

With the intoduction of hardware tag-based KASAN some kernel checks of this kind: ifdef CONFIG_KASAN will be updated to: if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code that isn't linked with KASAN runtime and shouldn't have any KASAN annotations. Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN. Link: https://lkml.kernel.org/r/9d84bfaaf8fabe0fc89f913c9e420a30bd31a260.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver Acked-by: Vasily Gorbik Reviewed-by: Alexander Potapenko Tested-by: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390/boot: add build-id to decompressor

2020-12-09T20:02:07Z

More and more functionality from the early boot phase gets carried over to the decompressor. With this the complexity of the code and thus the chance to introduce bugs increases. In order to be able to debug these early boot bugs the distributions have to package the decompressors vmlinux together with the other debuginfos. However for that the distributions require the vmlinux to contain a build-id. Per default the section containing the build-id is placed first in the section table. So make sure to move it behind the .text section otherwise the image would be unbootable. Signed-off-by: Philipp Rudo Signed-off-by: Heiko Carstens

s390/decompressor: print cmdline and BEAR on pgm_check

2020-11-20T18:19:11Z

Add kernel command line and last breaking event. The kernel command line is taken from early_command_line and printed only if kernel is not running as protected virtualization guest and if it has been already initialized from the "COMMAND_LINE". Linux version 5.10.0-rc3-22794-gecaa72788df0-dirty (gor@tuxmaker) #28 SMP PREEMPT Mon Nov 9 17:41:20 CET 2020 Kernel command line: audit_enable=0 audit=0 selinux=0 crashkernel=296M root=/dev/dasda1 dasd=ec5b memblock=debug die Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c) R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3 GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a65c 000000000000bf60 0000000000000000 00000000000003c0 0000000000000000 0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018 000000000311c000 0000000000010070 0000000000012f82 000000000000bea8 Call Trace: (sp:000000000000bea8 [<000000000002016e>] 000000000002016e) sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0 Last Breaking-Event-Address: [<00000000000135ba>] strcmp+0x22/0x24 Reviewed-by: Alexander Egorenkov Acked-by: Viktor Mihajlovski Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/decompressor: add stacktrace support

2020-11-20T18:19:11Z

Decompressor works on a single statically allocated stack. Stacktrace implementation with -mbackchain just takes few lines of code. Linux version 5.10.0-rc3-22793-g0f84a355b776-dirty (gor@tuxmaker) #27 SMP PREEMPT Mon Nov 9 17:30:18 CET 2020 Kernel fault: interruption code 0005 ilc:2 PSW : 0000000180000000 0000000000012f92 (parse_boot_command_line+0x27a/0x46c) R:0 T:0 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 RI:0 EA:3 GPRS: 0000000000000000 00ffffffffffffff 0000000000000000 000000000001a62c 000000000000bf60 0000000000000000 00000000000003c0 0000000000000000 0000000000000080 000000000002322d 000000007f29ef20 0000000000efd018 000000000311c000 0000000000010070 0000000000012f82 000000000000bea8 Call Trace: (sp:000000000000bea8 [<000000000002016e>] 000000000002016e) sp:000000000000bf18 [<0000000000012408>] startup_kernel+0x88/0x2fc sp:000000000000bf60 [<00000000000100c4>] startup_normal+0xb0/0xb0 Reviewed-by: Alexander Egorenkov Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens