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| author | Michael Pratt <mpratt@google.com> | 2018-09-06 17:21:59 -0700 |
|---|---|---|
| committer | Ian Lance Taylor <iant@golang.org> | 2018-09-07 22:50:28 +0000 |
| commit | 43f54c8d2e3bddfc6ad7887286eb6564986cb6ad (patch) | |
| tree | 4883ebc958846178fbcf544e44d22a6599b42be6 /src/runtime/sys_linux_386.s | |
| parent | ceb7745cc846f798531ef019162dd9f1dabfea12 (diff) | |
| download | go-43f54c8d2e3bddfc6ad7887286eb6564986cb6ad.tar.xz | |
runtime: use tgkill for raise
raise uses tkill to send a signal to the current thread. For this use,
tgkill is functionally equivalent to tkill expect that it also takes the
pid as the first argument.
Using tgkill makes it simpler to run a Go program in a strict sandbox.
With kill and tgkill, the sandbox policy (e.g., seccomp) can prevent the
program from sending signals to other processes by checking that the
first argument == getpid().
With tkill, the policy must whitelist all tids in the process, which is
effectively impossible given Go's dynamic thread creation.
Fixes #27548
Change-Id: I8ed282ef1f7215b02ef46de144493e36454029ea
Reviewed-on: https://go-review.googlesource.com/133975
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/sys_linux_386.s')
| -rw-r--r-- | src/runtime/sys_linux_386.s | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s index 8d5a4ff977..4e914f3e60 100644 --- a/src/runtime/sys_linux_386.s +++ b/src/runtime/sys_linux_386.s @@ -48,7 +48,6 @@ #define SYS_mincore 218 #define SYS_madvise 219 #define SYS_gettid 224 -#define SYS_tkill 238 #define SYS_futex 240 #define SYS_sched_getaffinity 242 #define SYS_set_thread_area 243 @@ -57,6 +56,7 @@ #define SYS_epoll_ctl 255 #define SYS_epoll_wait 256 #define SYS_clock_gettime 265 +#define SYS_tgkill 270 #define SYS_epoll_create1 329 TEXT runtime·exit(SB),NOSPLIT,$0 @@ -155,11 +155,14 @@ TEXT runtime·gettid(SB),NOSPLIT,$0-4 RET TEXT runtime·raise(SB),NOSPLIT,$12 + MOVL $SYS_getpid, AX + INVOKE_SYSCALL + MOVL AX, BX // arg 1 pid MOVL $SYS_gettid, AX INVOKE_SYSCALL - MOVL AX, BX // arg 1 tid - MOVL sig+0(FP), CX // arg 2 signal - MOVL $SYS_tkill, AX + MOVL AX, CX // arg 2 tid + MOVL sig+0(FP), DX // arg 3 signal + MOVL $SYS_tgkill, AX INVOKE_SYSCALL RET |