Bug #268336 continued -> Use Maks Verver's clever sighandler solution to emulate the missing lahf instruction on affected platforms

(Portage version: 2.1.6.13/cvs/Linux x86_64)

1 files changed, 29 insertions, 0 deletions

diff --git a/www-plugins/adobe-flash/files/flashplugin-lahf-fix.c b/www-plugins/adobe-flash/files/flashplugin-lahf-fix.c
new file mode 100644
index 000000000000..9338b7337317
--- /dev/null
+++ b/www-plugins/adobe-flash/files/flashplugin-lahf-fix.c
@@ -0,0 +1,29 @@
+/* Simple work-around for running the 64-bit Adobe Flash plug-in version 10
+   on Athlon64 processors without support for the lahf instruction.
+
+Compile with:
+cc -fPIC -shared -nostdlib -lc -oflashplugin-lahf-fix.so flashplugin-lahf-fix.c
+Then place the .so file in the plug-in directory (e.g. $HOME/.mozilla/plugins)
+or use LD_PRELOAD to force Firefox to load the library.
+
+   - Maks Verver <maksverver@geocities.com> July 2009 */
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <signal.h>
+#include <ucontext.h>
+
+static void sig_handler(int signal, siginfo_t *info, void *context) {
+	if (signal != SIGILL) return;
+	if (*(char*)info->si_addr != (char)0x9f) abort();
+	greg_t *regs = ((ucontext_t*)context)->uc_mcontext.gregs;
+	((char*)&regs[REG_RAX])[1] = ((char*)&regs[REG_EFL])[0];
+	regs[REG_RIP]++;
+}
+
+static struct sigaction old_sa, new_sa = {
+	.sa_flags     = SA_SIGINFO,
+	.sa_sigaction = &sig_handler };
+
+int _init() { sigaction(SIGILL, &new_sa, &old_sa); return 0; }
+int _fini() { sigaction(SIGILL, &old_sa, &new_sa); return 0; }