53 lines
1.9 KiB
Diff
53 lines
1.9 KiB
Diff
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From 5a224b981ee32d7cf59aaa9e2c101af65a275edc Mon Sep 17 00:00:00 2001
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From: Julien Lepiller <julien@lepiller.eu>
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Date: Mon, 20 Feb 2023 19:14:12 +0100
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Subject: [PATCH] Dynamically allocate the alternate signal stack.
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This patch is a backport of https://github.com/ocaml/ocaml/pull/10266.
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---
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asmrun/signals_asm.c | 19 +++++++++++--------
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1 file changed, 11 insertions(+), 8 deletions(-)
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diff --git a/asmrun/signals_asm.c b/asmrun/signals_asm.c
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index 3895d75..7e2abe8 100644
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--- a/asmrun/signals_asm.c
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+++ b/asmrun/signals_asm.c
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@@ -182,7 +182,6 @@ DECLARE_SIGNAL_HANDLER(trap_handler)
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#ifdef HAS_STACK_OVERFLOW_DETECTION
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static char * system_stack_top;
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-static char sig_alt_stack[SIGSTKSZ];
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#if defined(SYS_linux)
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/* PR#4746: recent Linux kernels with support for stack randomization
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@@ -274,15 +273,19 @@ void caml_init_signals(void)
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#ifdef HAS_STACK_OVERFLOW_DETECTION
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{
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stack_t stk;
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- struct sigaction act;
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- stk.ss_sp = sig_alt_stack;
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+ stk.ss_sp = malloc(SIGSTKSZ);
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stk.ss_size = SIGSTKSZ;
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stk.ss_flags = 0;
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- SET_SIGACT(act, segv_handler);
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- act.sa_flags |= SA_ONSTACK | SA_NODEFER;
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- sigemptyset(&act.sa_mask);
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- system_stack_top = (char *) &act;
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- if (sigaltstack(&stk, NULL) == 0) { sigaction(SIGSEGV, &act, NULL); }
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+ if (stk.ss_sp != NULL) {
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+ if (sigaltstack(&stk, NULL) != -1) {
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+ struct sigaction act;
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+ SET_SIGACT(act, segv_handler);
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+ act.sa_flags |= SA_ONSTACK | SA_NODEFER;
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+ sigemptyset(&act.sa_mask);
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+ system_stack_top = (char *) &act;
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+ sigaction(SIGSEGV, &act, NULL);
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+ }
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+ }
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}
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#endif
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}
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--
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2.38.1
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