From 843fc7f7f26a6507fe896a79ed1b474c35c4300f Mon Sep 17 00:00:00 2001 From: Jonathan Callen Date: Tue, 24 Jul 2012 22:45:22 -0400 Subject: execute: Fix seccomp support on x32 In the x32 ABI, syscall numbers start at 0x40000000. Mask that bit on x32 for lookups in the syscall_names array and syscall_filter and ensure that syscall.h is parsed correctly. [zj: added SYSCALL_TO_INDEX, INDEX_TO_SYSCALL macros.] --- src/core/execute.c | 2 +- src/core/load-fragment.c | 2 ++ src/core/syscall-list.c | 1 + src/core/syscall-list.h | 14 ++++++++++++++ 4 files changed, 18 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/core/execute.c b/src/core/execute.c index 65a10af3b..1413c9110 100644 --- a/src/core/execute.c +++ b/src/core/execute.c @@ -957,7 +957,7 @@ static int apply_seccomp(uint32_t *syscall_filter) { for (i = 0, n = 0; i < syscall_max(); i++) if (syscall_filter[i >> 4] & (1 << (i & 31))) { struct sock_filter item[] = { - BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, i, 0, 1), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, INDEX_TO_SYSCALL(i), 0, 1), BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW) }; diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index f82ddd530..8436d4f95 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -2120,10 +2120,12 @@ int config_parse_documentation( } static void syscall_set(uint32_t *p, int nr) { + nr = SYSCALL_TO_INDEX(nr); p[nr >> 4] |= 1 << (nr & 31); } static void syscall_unset(uint32_t *p, int nr) { + nr = SYSCALL_TO_INDEX(nr); p[nr >> 4] &= ~(1 << (nr & 31)); } diff --git a/src/core/syscall-list.c b/src/core/syscall-list.c index 05fad3e15..b608e8582 100644 --- a/src/core/syscall-list.c +++ b/src/core/syscall-list.c @@ -32,6 +32,7 @@ const struct syscall_name *lookup_syscall(register const char *str, register uns #include "syscall-from-name.h" const char *syscall_to_name(int id) { + id = SYSCALL_TO_INDEX(id); if (id < 0 || id >= (int) ELEMENTSOF(syscall_names)) return NULL; diff --git a/src/core/syscall-list.h b/src/core/syscall-list.h index 0fc685960..503838b7f 100644 --- a/src/core/syscall-list.h +++ b/src/core/syscall-list.h @@ -22,6 +22,20 @@ along with systemd; If not, see . ***/ +#if defined __x86_64__ && defined __ILP32__ +/* The x32 ABI defines all of its syscalls with bit 30 set, which causes + issues when attempting to use syscalls as simple indicies into an array. + Instead, use the syscall id & ~SYSCALL_MASK as the index, and | the + internal id with the syscall mask as needed. +*/ +#include +#define SYSCALL_TO_INDEX(x) ((x) & ~__X32_SYSCALL_BIT) +#define INDEX_TO_SYSCALL(x) ((x) | __X32_SYSCALL_BIT) +#else +#define SYSCALL_TO_INDEX(x) (x) +#define INDEX_TO_SYSCALL(x) (x) +#endif + const char *syscall_to_name(int id); int syscall_from_name(const char *name); -- cgit v1.2.3