diff options
Diffstat (limited to 'gcc-4.9/libgcc/config/pa/linux-unwind.h')
| -rw-r--r-- | gcc-4.9/libgcc/config/pa/linux-unwind.h | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/gcc-4.9/libgcc/config/pa/linux-unwind.h b/gcc-4.9/libgcc/config/pa/linux-unwind.h index 485f2d98e..4a3cfffd1 100644 --- a/gcc-4.9/libgcc/config/pa/linux-unwind.h +++ b/gcc-4.9/libgcc/config/pa/linux-unwind.h @@ -32,6 +32,17 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #include <signal.h> #include <sys/ucontext.h> +/* Return TRUE if read access to *P is allowed. */ + +static inline long +pa32_read_access_ok (void *p) +{ + long ret; + + __asm__ ("proberi (%1),3,%0" : "=r" (ret) : "r" (p) :); + return ret; +} + /* Unfortunately, because of various bugs and changes to the kernel, we have several cases to deal with. @@ -48,7 +59,12 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see tell us how to locate the sigcontext structure. Note that with a 2.4 64-bit kernel, the signal context is not properly - passed back to userspace so the unwind will not work correctly. */ + passed back to userspace so the unwind will not work correctly. + + There is also a bug in various glibc versions. The (CONTEXT)->ra + for the outermost frame is not marked as undefined, so we need to + check whether read access is allowed for all the accesses used in + searching for the signal trampoline. */ #define MD_FALLBACK_FRAME_STATE_FOR pa32_fallback_frame_state @@ -73,14 +89,17 @@ pa32_fallback_frame_state (struct _Unwind_Context *context, e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31 08000240 nop */ - if (pc[0] == 0x34190000 || pc[0] == 0x34190002) + if (pa32_read_access_ok (pc) + && (pc[0] == 0x34190000 || pc[0] == 0x34190002)) off = 4*4; - else if (pc[4] == 0x34190000 || pc[4] == 0x34190002) + else if (pa32_read_access_ok (&pc[4]) + && (pc[4] == 0x34190000 || pc[4] == 0x34190002)) { pc += 4; off = 10 * 4; } - else if (pc[5] == 0x34190000 || pc[5] == 0x34190002) + else if (pa32_read_access_ok (&pc[5]) + && (pc[5] == 0x34190000 || pc[5] == 0x34190002)) { pc += 5; off = 10 * 4; @@ -96,13 +115,16 @@ pa32_fallback_frame_state (struct _Unwind_Context *context, word boundary and we can then determine the frame offset. */ sp = (unsigned long)context->ra; pc = (unsigned int *)sp; - if ((pc[0] == 0x34190000 || pc[0] == 0x34190002) && (sp & 4)) + if ((sp & 4) + && pa32_read_access_ok (pc) + && (pc[0] == 0x34190000 || pc[0] == 0x34190002)) off = 5 * 4; else return _URC_END_OF_STACK; } - if (pc[1] != 0x3414015a + if (!pa32_read_access_ok (&pc[3]) + || pc[1] != 0x3414015a || pc[2] != 0xe4008200 || pc[3] != 0x08000240) return _URC_END_OF_STACK; |