From fe8973a3ad0905cb9ba2d42db42ed51de14737df Mon Sep 17 00:00:00 2001 From: Alexander Egorenkov Date: Fri, 27 Jan 2023 14:52:41 +0100 Subject: watchdog: diag288_wdt: do not use stack buffers for hardware data With CONFIG_VMAP_STACK=y the stack is allocated from the vmalloc space. Data passed to a hardware or a hypervisor interface that requires V=R can no longer be allocated on the stack. Use kmalloc() to get memory for a diag288 command. Signed-off-by: Alexander Egorenkov Reviewed-by: Heiko Carstens Cc: Signed-off-by: Heiko Carstens --- drivers/watchdog/diag288_wdt.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/diag288_wdt.c b/drivers/watchdog/diag288_wdt.c index 4cb10877017c..2112eef69969 100644 --- a/drivers/watchdog/diag288_wdt.c +++ b/drivers/watchdog/diag288_wdt.c @@ -268,12 +268,21 @@ static int __init diag288_init(void) char ebc_begin[] = { 194, 197, 199, 201, 213 }; + char *ebc_cmd; watchdog_set_nowayout(&wdt_dev, nowayout_info); if (MACHINE_IS_VM) { - if (__diag288_vm(WDT_FUNC_INIT, 15, - ebc_begin, sizeof(ebc_begin)) != 0) { + ebc_cmd = kmalloc(sizeof(ebc_begin), GFP_KERNEL); + if (!ebc_cmd) { + pr_err("The watchdog cannot be initialized\n"); + return -ENOMEM; + } + memcpy(ebc_cmd, ebc_begin, sizeof(ebc_begin)); + ret = __diag288_vm(WDT_FUNC_INIT, 15, + ebc_cmd, sizeof(ebc_begin)); + kfree(ebc_cmd); + if (ret != 0) { pr_err("The watchdog cannot be initialized\n"); return -EINVAL; } -- cgit From 32e40f9506b9e32917eb73154f93037b443124d1 Mon Sep 17 00:00:00 2001 From: Alexander Egorenkov Date: Fri, 27 Jan 2023 14:52:42 +0100 Subject: watchdog: diag288_wdt: fix __diag288() inline assembly The DIAG 288 statement consumes an EBCDIC string the address of which is passed in a register. Use a "memory" clobber to tell the compiler that memory is accessed within the inline assembly. Signed-off-by: Alexander Egorenkov Reviewed-by: Heiko Carstens Cc: Signed-off-by: Heiko Carstens --- drivers/watchdog/diag288_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/watchdog/diag288_wdt.c b/drivers/watchdog/diag288_wdt.c index 2112eef69969..6ca5d9515d85 100644 --- a/drivers/watchdog/diag288_wdt.c +++ b/drivers/watchdog/diag288_wdt.c @@ -86,7 +86,7 @@ static int __diag288(unsigned int func, unsigned int timeout, "1:\n" EX_TABLE(0b, 1b) : "+d" (err) : "d"(__func), "d"(__timeout), - "d"(__action), "d"(__len) : "1", "cc"); + "d"(__action), "d"(__len) : "1", "cc", "memory"); return err; } -- cgit From 7ab41c2c08a32132ba8c14624910e2fe8ce4ba4b Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Sun, 29 Jan 2023 23:47:23 +0100 Subject: s390/decompressor: specify __decompress() buf len to avoid overflow Historically calls to __decompress() didn't specify "out_len" parameter on many architectures including s390, expecting that no writes beyond uncompressed kernel image are performed. This has changed since commit 2aa14b1ab2c4 ("zstd: import usptream v1.5.2") which includes zstd library commit 6a7ede3dfccb ("Reduce size of dctx by reutilizing dst buffer (#2751)"). Now zstd decompression code might store literal buffer in the unwritten portion of the destination buffer. Since "out_len" is not set, it is considered to be unlimited and hence free to use for optimization needs. On s390 this might corrupt initrd or ipl report which are often placed right after the decompressor buffer. Luckily the size of uncompressed kernel image is already known to the decompressor, so to avoid the problem simply specify it in the "out_len" parameter. Link: https://github.com/facebook/zstd/commit/6a7ede3dfccb Signed-off-by: Vasily Gorbik Tested-by: Alexander Egorenkov Link: https://lore.kernel.org/r/patch-1.thread-41c676.git-41c676c2d153.your-ad-here.call-01675030179-ext-9637@work.hours Signed-off-by: Heiko Carstens --- arch/s390/boot/decompressor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/boot/decompressor.c b/arch/s390/boot/decompressor.c index 8dcd7af2911a..b519a1f045d8 100644 --- a/arch/s390/boot/decompressor.c +++ b/arch/s390/boot/decompressor.c @@ -80,6 +80,6 @@ void *decompress_kernel(void) void *output = (void *)decompress_offset; __decompress(_compressed_start, _compressed_end - _compressed_start, - NULL, NULL, output, 0, NULL, error); + NULL, NULL, output, vmlinux.image_size, NULL, error); return output; } -- cgit