+++ /dev/null
-From a832070f3665d29a8a06652c15f94d144c24ac69 Mon Sep 17 00:00:00 2001
-From: Stephen Webb <swebb@blackberry.com>
-Date: Mon, 22 Apr 2024 15:56:54 -0400
-Subject: [PATCH 4/5] Rework inline aarch64 as for setcontext
-
-Modern GC and clang were barfing on the inline asm constraints for the
-aarch64-linux setcontext() replacement. Reformulated the asm code to
-reduce the required constraints.
-
-Upstream-Status: Backport
-Signed-off-by: Ross Burton <ross.burton@arm.com>
----
- src/aarch64/Gos-linux.c | 115 +++++++++++++++++++++-------------------
- 1 file changed, 61 insertions(+), 54 deletions(-)
-
-diff --git a/src/aarch64/Gos-linux.c b/src/aarch64/Gos-linux.c
-index 7cd8c879..1e494962 100644
---- a/src/aarch64/Gos-linux.c
-+++ b/src/aarch64/Gos-linux.c
-@@ -2,6 +2,7 @@
- Copyright (C) 2008 CodeSourcery
- Copyright (C) 2011-2013 Linaro Limited
- Copyright (C) 2012 Tommi Rantala <tt.rantala@gmail.com>
-+ Copyright 2024 Stephen M. Webb <swebb@blackberry.com>
-
- This file is part of libunwind.
-
-@@ -28,6 +29,28 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
-
- #ifndef UNW_REMOTE_ONLY
-
-+/* Magic constants generated from gen-offsets.c */
-+#define SC_R0_OFF "8"
-+#define SC_R2_OFF "24"
-+#define SC_R18_OFF "152"
-+#define SC_R20_OFF "168"
-+#define SC_R22_OFF "184"
-+#define SC_R24_OFF "200"
-+#define SC_R26_OFF "216"
-+#define SC_R28_OFF "232"
-+#define SC_R30_OFF "248"
-+
-+#define FP_R08_OFF "80"
-+#define FP_R09_OFF "88"
-+#define FP_R10_OFF "96"
-+#define FP_R11_OFF "104"
-+#define FP_R12_OFF "112"
-+#define FP_R13_OFF "120"
-+#define FP_R14_OFF "128"
-+#define FP_R15_OFF "136"
-+
-+#define SC_SP_OFF "0x100"
-+
- HIDDEN int
- aarch64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
- {
-@@ -36,65 +59,49 @@ aarch64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
-
- if (c->sigcontext_format == AARCH64_SCF_NONE)
- {
-+
-+ /*
-+ * This is effectively the old POSIX setcontext().
-+ *
-+ * This inline asm is broken up to use local scratch registers for the
-+ * uc_mcontext.regs and FPCTX base addresses because newer versions of GCC
-+ * and clang barf on too many constraints (gh-702) when the C array
-+ * elements are used directly.
-+ *
-+ * Clobbers aren't required for the inline asm because they just convince
-+ * the compiler to save those registers and they never get restored
-+ * becauise the asm ends with a plain ol' ret.
-+ */
-+ register void* uc_mcontext __asm__ ("x5") = (void*) &uc->uc_mcontext;
-+ register void* fpctx __asm__ ("x4") = (void*) GET_FPCTX(uc);
-+
- /* Since there are no signals involved here we restore EH and non scratch
- registers only. */
- __asm__ __volatile__ (
-- "ldr x0, %[x0]\n\t"
-- "ldr x1, %[x1]\n\t"
-- "ldr x2, %[x2]\n\t"
-- "ldr x3, %[x3]\n\t"
-- "ldr x19, %[x19]\n\t"
-- "ldr x20, %[x20]\n\t"
-- "ldr x21, %[x21]\n\t"
-- "ldr x22, %[x22]\n\t"
-- "ldr x23, %[x23]\n\t"
-- "ldr x24, %[x24]\n\t"
-- "ldr x25, %[x25]\n\t"
-- "ldr x26, %[x26]\n\t"
-- "ldr x27, %[x27]\n\t"
-- "ldr x28, %[x28]\n\t"
-- "ldr x29, %[x29]\n\t"
-- "ldr x30, %[x30]\n\t"
-- "ldr d8, %[d8]\n\t"
-- "ldr d9, %[d9]\n\t"
-- "ldr d10, %[d10]\n\t"
-- "ldr d11, %[d11]\n\t"
-- "ldr d12, %[d12]\n\t"
-- "ldr d13, %[d13]\n\t"
-- "ldr d14, %[d14]\n\t"
-- "ldr d15, %[d15]\n\t"
-- "ldr x5, %[sp]\n\t"
-+ "ldp x0, x1, [x5, " SC_R0_OFF "]\n\t"
-+ "ldp x2, x3, [x5, " SC_R2_OFF "]\n\t"
-+ "ldp x18, x19, [x5, " SC_R18_OFF "]\n\t"
-+ "ldp x20, x21, [x5, " SC_R20_OFF "]\n\t"
-+ "ldp x22, x23, [x5, " SC_R22_OFF "]\n\t"
-+ "ldp x24, x25, [x5, " SC_R24_OFF "]\n\t"
-+ "ldp x26, x27, [x5, " SC_R26_OFF "]\n\t"
-+ "ldp x28, x29, [x5, " SC_R28_OFF "]\n\t"
-+ "ldr x30, [x5, " SC_R30_OFF "]\n\t"
-+ "ldr d8, [x4, " FP_R08_OFF "]\n\t"
-+ "ldr d9, [x4, " FP_R09_OFF "]\n\t"
-+ "ldr d10, [x4, " FP_R10_OFF "]\n\t"
-+ "ldr d11, [x4, " FP_R11_OFF "]\n\t"
-+ "ldr d12, [x4, " FP_R12_OFF "]\n\t"
-+ "ldr d13, [x4, " FP_R13_OFF "]\n\t"
-+ "ldr d14, [x4, " FP_R14_OFF "]\n\t"
-+ "ldr d15, [x4, " FP_R15_OFF "]\n\t"
-+ "ldr x5, [x5, " SC_SP_OFF "]\n\t"
- "mov sp, x5\n\t"
- "ret\n"
-- :
-- : [x0] "m"(uc->uc_mcontext.regs[0]),
-- [x1] "m"(uc->uc_mcontext.regs[1]),
-- [x2] "m"(uc->uc_mcontext.regs[2]),
-- [x3] "m"(uc->uc_mcontext.regs[3]),
-- [x19] "m"(uc->uc_mcontext.regs[19]),
-- [x20] "m"(uc->uc_mcontext.regs[20]),
-- [x21] "m"(uc->uc_mcontext.regs[21]),
-- [x22] "m"(uc->uc_mcontext.regs[22]),
-- [x23] "m"(uc->uc_mcontext.regs[23]),
-- [x24] "m"(uc->uc_mcontext.regs[24]),
-- [x25] "m"(uc->uc_mcontext.regs[25]),
-- [x26] "m"(uc->uc_mcontext.regs[26]),
-- [x27] "m"(uc->uc_mcontext.regs[27]),
-- [x28] "m"(uc->uc_mcontext.regs[28]),
-- [x29] "m"(uc->uc_mcontext.regs[29]), /* FP */
-- [x30] "m"(uc->uc_mcontext.regs[30]), /* LR */
-- [d8] "m"(GET_FPCTX(uc)->vregs[8]),
-- [d9] "m"(GET_FPCTX(uc)->vregs[9]),
-- [d10] "m"(GET_FPCTX(uc)->vregs[10]),
-- [d11] "m"(GET_FPCTX(uc)->vregs[11]),
-- [d12] "m"(GET_FPCTX(uc)->vregs[12]),
-- [d13] "m"(GET_FPCTX(uc)->vregs[13]),
-- [d14] "m"(GET_FPCTX(uc)->vregs[14]),
-- [d15] "m"(GET_FPCTX(uc)->vregs[15]),
-- [sp] "m"(uc->uc_mcontext.sp)
-- : "x0", "x1", "x2", "x3", "x19", "x20", "x21", "x22", "x23", "x24",
-- "x25", "x26", "x27", "x28", "x29", "x30"
-- );
-+ :
-+ : [uc_mcontext] "r"(uc_mcontext),
-+ [fpctx] "r"(fpctx)
-+ );
- }
- else
- {
---
-2.34.1
-
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
