* [PATCH] 2.6.3: ia64_abort(): Use guard page instead of page 0
@ 2004-02-18 22:13 Jason Uhlenkott
0 siblings, 0 replies; only message in thread
From: Jason Uhlenkott @ 2004-02-18 22:13 UTC (permalink / raw)
To: linux-ia64
The ia64_abort() macro deliberately writes to address 0 in order to
trigger a page fault and an Oops. This won't work if the process has
mapped something into page zero: We'll just print the "kernel BUG"
message and continue (after having stomped on whatever user memory was
at address 0).
A solution is to write to the guard page in region 5, which is
guaranteed to trigger a page fault.
--- linux-2.6.3.orig/include/asm-ia64/bug.h Tue Feb 17 19:57:12 2004
+++ linux-2.6.3/include/asm-ia64/bug.h Wed Feb 18 14:00:14 2004
@@ -4,7 +4,7 @@
#if (__GNUC__ > 3) || (__GNUC__ = 3 && __GNUC_MINOR__ >= 1)
# define ia64_abort() __builtin_trap()
#else
-# define ia64_abort() (*(volatile int *) 0 = 0)
+# define ia64_abort() (*(volatile int *) (0xa000000000000000+2*PERCPU_PAGE_SIZE) = 0)
#endif
#define BUG() do { printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); ia64_abort(); } while (0)
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2004-02-18 22:13 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2004-02-18 22:13 [PATCH] 2.6.3: ia64_abort(): Use guard page instead of page 0 Jason Uhlenkott
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox