The following commit has been merged into the x86/cpu branch of tip:
Commit-ID: 1eefe7a85678a056951cd9efb09820c1b0a1b4da
Gitweb: https://git.kernel.org/tip/1eefe7a85678a056951cd9efb09820c1b0a1b4da
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Wed, 15 Sep 2021 16:39:18 +02:00
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Thu, 23 Sep 2021 16:30:11 +02:00
x86/umip: Downgrade warning messages to debug loglevel
After four years in the wild, those have not fullfilled their
initial purpose of pushing people to fix their software to not use
UMIP-emulated instructions, and to warn users about the degraded
emulation performance.
Yet, the only thing that "degrades" performance is overflowing dmesg
with those:
[Di Sep 7 00:24:05 2021] umip_printk: 1345 callbacks suppressed
[Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: SIDT instruction cannot be used by applications.
[Di Sep 7 00:24:05 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b7c0: For now, expensive software emulation returns the result.
...
[Di Sep 7 00:26:06 2021] umip_printk: 2227 callbacks suppressed
[Di Sep 7 00:26:06 2021] umip: someapp.exe[29231] ip:14064cdba sp:11b940: SIDT instruction cannot be used by applications.
and users don't really care about that - they just want to play their
games in wine.
So convert those to debug loglevel - in case someone is still interested
in them, someone can boot with "debug" on the kernel cmdline.
Reported-by: Marcus Rückert <mrueckert@xxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20210907200454.30458-1-bp@xxxxxxxxx
---
arch/x86/kernel/umip.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 576b47e..5a4b213 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -92,8 +92,8 @@ static const char * const umip_insns[5] = {
#define umip_pr_err(regs, fmt, ...) \
umip_printk(regs, KERN_ERR, fmt, ##__VA_ARGS__)
-#define umip_pr_warn(regs, fmt, ...) \
- umip_printk(regs, KERN_WARNING, fmt, ##__VA_ARGS__)
+#define umip_pr_debug(regs, fmt, ...) \
+ umip_printk(regs, KERN_DEBUG, fmt, ##__VA_ARGS__)
/**
* umip_printk() - Print a rate-limited message
@@ -361,10 +361,10 @@ bool fixup_umip_exception(struct pt_regs *regs)
if (umip_inst < 0)
return false;
- umip_pr_warn(regs, "%s instruction cannot be used by applications.\n",
+ umip_pr_debug(regs, "%s instruction cannot be used by applications.\n",
umip_insns[umip_inst]);
- umip_pr_warn(regs, "For now, expensive software emulation returns the result.\n");
+ umip_pr_debug(regs, "For now, expensive software emulation returns the result.\n");
if (emulate_umip_insn(&insn, umip_inst, dummy_data, &dummy_data_size,
user_64bit_mode(regs)))
|