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| author | Jes Sorensen <jes@sgi.com> | 2006-02-28 09:42:23 -0800 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2006-02-28 09:42:23 -0800 |
| commit | d2b176ed878d4d5fcc0bd35656dfd373f3702af9 (patch) | |
| tree | f5febd7d77fc374ddef9cbe549732bcb3b125c8b /arch/ia64 | |
| parent | c8c1635faa7c97329111ce32b927d37306521822 (diff) | |
| download | linux-d2b176ed878d4d5fcc0bd35656dfd373f3702af9.tar.gz linux-d2b176ed878d4d5fcc0bd35656dfd373f3702af9.tar.bz2 linux-d2b176ed878d4d5fcc0bd35656dfd373f3702af9.zip | |
[IA64] sysctl option to silence unaligned trap warnings
Allow sysadmin to disable all warnings about userland apps
making unaligned accesses by using:
# echo 1 > /proc/sys/kernel/ignore-unaligned-usertrap
Rather than having to use prctl on a process by process basis.
Default behaivour leaves the warnings enabled.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
| -rw-r--r-- | arch/ia64/kernel/unaligned.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/arch/ia64/kernel/unaligned.c b/arch/ia64/kernel/unaligned.c index 112913896844..1e357550c776 100644 --- a/arch/ia64/kernel/unaligned.c +++ b/arch/ia64/kernel/unaligned.c @@ -53,6 +53,15 @@ dump (const char *str, void *vp, size_t len) #define SIGN_EXT9 0xffffffffffffff00ul /* + * sysctl settable hook which tells the kernel whether to honor the + * IA64_THREAD_UAC_NOPRINT prctl. Because this is user settable, we want + * to allow the super user to enable/disable this for security reasons + * (i.e. don't allow attacker to fill up logs with unaligned accesses). + */ +int no_unaligned_warning; +static int noprint_warning; + +/* * For M-unit: * * opcode | m | x6 | @@ -1324,8 +1333,9 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs) if ((current->thread.flags & IA64_THREAD_UAC_SIGBUS) != 0) goto force_sigbus; - if (!(current->thread.flags & IA64_THREAD_UAC_NOPRINT) - && within_logging_rate_limit()) + if (!no_unaligned_warning && + !(current->thread.flags & IA64_THREAD_UAC_NOPRINT) && + within_logging_rate_limit()) { char buf[200]; /* comm[] is at most 16 bytes... */ size_t len; @@ -1340,7 +1350,22 @@ ia64_handle_unaligned (unsigned long ifa, struct pt_regs *regs) if (user_mode(regs)) tty_write_message(current->signal->tty, buf); buf[len-1] = '\0'; /* drop '\r' */ - printk(KERN_WARNING "%s", buf); /* watch for command names containing %s */ + /* watch for command names containing %s */ + printk(KERN_WARNING "%s", buf); + } else { + if (no_unaligned_warning && !noprint_warning) { + noprint_warning = 1; + printk(KERN_WARNING "%s(%d) encountered an " + "unaligned exception which required\n" + "kernel assistance, which degrades " + "the performance of the application.\n" + "Unaligned exception warnings have " + "been disabled by the system " + "administrator\n" + "echo 0 > /proc/sys/kernel/ignore-" + "unaligned-usertrap to re-enable\n", + current->comm, current->pid); + } } } else { if (within_logging_rate_limit()) |