[Tarantool-patches] [PATCH luajit 1/4] ARM, ARM64, PPC: Fix TSETR fallback.
Sergey Ostanevich
sergos at tarantool.org
Wed Jun 2 15:04:25 MSK 2021
Hi!
Thanks for the patch!
See my 3 cents below.
Sergos
> On 24 May 2021, at 16:27, Sergey Kaplun <skaplun at tarantool.org> wrote:
>
> From: Mike Pall <mike>
>
> Thanks to Javier Guerra Giraldez.
>
> (cherry picked from commit ae20998ff5aaacc8e3afd46c64e28a8e039b58a1)
>
> This patch fixes the issue introduced by commits
> f307d0adafc7e35d2dc1c461d50f6572c5e6bca8 ('ARM64: Add build
> infrastructure and initial port of interpreter.') for arm64 and
> 73ef845fcaf65937ad63e9cf6b681cb3e61f4504 ('Add special bytecodes for
> builtins.') for arm and ppc. Within the mentioned commits the new
> bytecode TSETR is introduced for the corresponding architectures.
>
> When the new index of the table processed during this bytecode is the
> integer, that is greater than asize of the table, the VM fallbacks to
> vmeta_tsetr, for calling
> lj_tab_setinth(lua_State *L, GCtab *t, int32_t key). The first argument
> CARG1 is not set by the VM and contains an invalid value, so the
> mentioned call leads to crash.
> This patch adds the missed set of CARG1 to the right value.
>
> Sergey Kaplun:
> * added the description and the test for the problem
>
> Resolves tarantool/tarantool#6084
> Part of tarantool/tarantool#5629
> ---
> src/vm_arm.dasc | 1 +
> src/vm_arm64.dasc | 1 +
> src/vm_ppc.dasc | 1 +
> test/tarantool-tests/CMakeLists.txt | 9 ++++---
> ...-missed-carg1-in-bctsetr-fallback.test.lua | 25 +++++++++++++++++++
> test/tarantool-tests/utils.lua | 22 ++++++++++++++++
> 6 files changed, 55 insertions(+), 4 deletions(-)
> create mode 100644 test/tarantool-tests/gh-6084-missed-carg1-in-bctsetr-fallback.test.lua
>
> diff --git a/src/vm_arm.dasc b/src/vm_arm.dasc
> index ae2efdfd..21f7fecb 100644
> --- a/src/vm_arm.dasc
> +++ b/src/vm_arm.dasc
> @@ -701,6 +701,7 @@ static void build_subroutines(BuildCtx *ctx)
> |->vmeta_tsetr:
> | str BASE, L->base
> | .IOS mov RC, BASE
> + | mov CARG1, L
> | str PC, SAVE_PC
> | bl extern lj_tab_setinth // (lua_State *L, GCtab *t, int32_t key)
> | // Returns TValue *.
> diff --git a/src/vm_arm64.dasc b/src/vm_arm64.dasc
> index f783428f..6bf59509 100644
> --- a/src/vm_arm64.dasc
> +++ b/src/vm_arm64.dasc
> @@ -711,6 +711,7 @@ static void build_subroutines(BuildCtx *ctx)
> |->vmeta_tsetr:
> | sxtw CARG3, TMP1w
> | str BASE, L->base
> + | mov CARG1, L
> | str PC, SAVE_PC
> | bl extern lj_tab_setinth // (lua_State *L, GCtab *t, int32_t key)
> | // Returns TValue *.
> diff --git a/src/vm_ppc.dasc b/src/vm_ppc.dasc
> index 62e9b681..3f48b7ff 100644
> --- a/src/vm_ppc.dasc
> +++ b/src/vm_ppc.dasc
> @@ -995,6 +995,7 @@ static void build_subroutines(BuildCtx *ctx)
> |
> |->vmeta_tsetr:
> | stp BASE, L->base
> + | mr CARG1, L
> | stw PC, SAVE_PC
> | bl extern lj_tab_setinth // (lua_State *L, GCtab *t, int32_t key)
> | // Returns TValue *.
> diff --git a/test/tarantool-tests/CMakeLists.txt b/test/tarantool-tests/CMakeLists.txt
> index 475e2e5d..2fdb4d1f 100644
> --- a/test/tarantool-tests/CMakeLists.txt
> +++ b/test/tarantool-tests/CMakeLists.txt
> @@ -61,11 +61,12 @@ add_subdirectory(lj-flush-on-trace)
> add_subdirectory(misclib-getmetrics-capi)
>
> # The part of the memory profiler toolchain is located in tools
> -# directory and auxiliary tests-related modules are located in the
> -# current directory (but tests are run in the binary directory),
> -# so LUA_PATH need to be updated.
> +# directory, jit, profiler, and bytecode toolchains are located
> +# in src/ directory and auxiliary tests-related modules are
> +# located in the current directory (but tests are run in the
> +# binary directory), so LUA_PATH need to be updated.
> set(LUA_PATH
> - "${CMAKE_CURRENT_SOURCE_DIR}/?.lua\;${PROJECT_SOURCE_DIR}/tools/?.lua"
> + "${CMAKE_CURRENT_SOURCE_DIR}/?.lua\;${PROJECT_SOURCE_DIR}/tools/?.lua\;${PROJECT_SOURCE_DIR}/src/?.lua"
> )
> set(LUA_TEST_SUFFIX .test.lua)
> set(LUA_TEST_FLAGS --failures --shuffle)
> diff --git a/test/tarantool-tests/gh-6084-missed-carg1-in-bctsetr-fallback.test.lua b/test/tarantool-tests/gh-6084-missed-carg1-in-bctsetr-fallback.test.lua
> new file mode 100644
> index 00000000..26344274
> --- /dev/null
> +++ b/test/tarantool-tests/gh-6084-missed-carg1-in-bctsetr-fallback.test.lua
> @@ -0,0 +1,25 @@
> +local tap = require("tap")
> +local utils = require("utils")
Sorry, but
s-ostanevich:tarantool-tests s.ostanevich$ egrep -l "\<require\>.*\"" *.lua | wc -l
6
s-ostanevich:tarantool-tests s.ostanevich$ egrep -l "\<require\>.*\'" *.lua | wc -l
14
clearly votes for require(‘tap') against require("tap”)
> +
> +local test = tap.test("gh-6084-missed-carg1-in-bctsetr-fallback")
> +test:plan(1)
> +
> +-- Bytecode TSETR appears only in built-ins libraries, when doing
> +-- fixups for fast function written in Lua (i.e. `table.move()`),
> +-- by replacing all TSETV bytecodes with the TSETR.
> +-- See <src/host/genlibbc.lua> for more details.
> +
> +-- This test checks that fallback path, when the index of the new
> +-- set element is greater than the table's asize, doesn't lead
> +-- to a crash.
> +
> +-- We need to make sure the bytecode is present in the chosen
> +-- built-in to make sure our test is still valid.
> +assert(utils.hasbc(table.move, "TSETR"))
> +
> +-- Empty table has asize equals 0. Just copy its element (equals
> +-- nil) to the field by index 1 > 0, to fallback inside TSETR.
> +table.move({}, 1, 1, 1)
I would like to see the move is correctly performed, rather the fact
there were no crash. It gives a bigger space for unexpected behavior.
> +
> +test:ok(true)
> +os.exit(test:check() and 0 or 1)
> diff --git a/test/tarantool-tests/utils.lua b/test/tarantool-tests/utils.lua
> index c0403cf1..61d4de7a 100644
> --- a/test/tarantool-tests/utils.lua
> +++ b/test/tarantool-tests/utils.lua
> @@ -2,11 +2,14 @@ local M = {}
>
> local ffi = require('ffi')
> local tap = require('tap')
> +local bc = require('jit.bc')
>
> ffi.cdef([[
> int setenv(const char *name, const char *value, int overwrite);
> ]])
>
> +local function noop() end
Name of this one in a patch that messess with bytecodes is confusing. Could it
be a simpler one, like ‘empty’?
> +
> local function luacmd(args)
> -- arg[-1] is guaranteed to be not nil.
> local idx = -2
> @@ -89,4 +92,23 @@ function M.tweakenv(condition, variable)
> ffi.C.setenv(variable, testvar, 0)
> end
>
> +function M.hasbc(f, bytecode)
> + assert(type(f) == 'function', 'argument #1 should be a function')
> + assert(type(bytecode) == 'string', 'argument #2 should be a string')
> + local hasbc = false
> + -- Check the bytecode entry line by line.
> + local out = {
> + write = function(out, line)
> + if line:match(bytecode) then
> + hasbc = true
> + out.write = noop
> + end
> + end,
> + flush = noop,
> + close = noop,
> + }
> + bc.dump(f, out)
> + return hasbc
> +end
> +
> return M
> --
> 2.31.0
>
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