linux-user/hexagon: Implement setup_sigtramp

Continue to initialize the words on the stack, as documented.
However, use the off-stack trampoline.

Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-9-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Richard Henderson 2021-09-29 09:05:35 -04:00 committed by Laurent Vivier
parent e281c2bafe
commit c8ef02b1ac
2 changed files with 19 additions and 2 deletions

View file

@ -162,6 +162,11 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
setup_ucontext(&frame->uc, env, set);
tswap_siginfo(&frame->info, info);
/*
* The on-stack signal trampoline is no longer executed;
* however, the libgcc signal frame unwinding code checks
* for the presence of these two numeric magic values.
*/
install_sigtramp(frame->tramp);
env->gpr[HEX_REG_PC] = ka->_sa_handler;
@ -171,8 +176,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
frame_addr + offsetof(struct target_rt_sigframe, info);
env->gpr[HEX_REG_R02] =
frame_addr + offsetof(struct target_rt_sigframe, uc);
env->gpr[HEX_REG_LR] =
frame_addr + offsetof(struct target_rt_sigframe, tramp);
env->gpr[HEX_REG_LR] = default_rt_sigreturn;
return;
@ -271,3 +275,14 @@ badframe:
force_sig(TARGET_SIGSEGV);
return 0;
}
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 4 * 2, 0);
assert(tramp != NULL);
default_rt_sigreturn = sigtramp_page;
install_sigtramp(tramp);
unlock_user(tramp, sigtramp_page, 4 * 2);
}

View file

@ -31,4 +31,6 @@ typedef struct target_sigaltstack {
#include "../generic/signal.h"
#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
#endif /* TARGET_SIGNAL_H */