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Merge branch 'for-next/entry' into for-next/core

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* for-next/entry:
  arm64: syscall: unmask DAIF earlier for SVCs
This commit is contained in:
Will Deacon 2023-08-25 12:35:45 +01:00
commit cd07455764
2 changed files with 32 additions and 33 deletions
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32
arch/arm64/kernel/entry-common.c
View File

@ -355,6 +355,35 @@ static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs)
}
#endif /* CONFIG_ARM64_ERRATUM_1463225 */
/*
* As per the ABI exit SME streaming mode and clear the SVE state not
* shared with FPSIMD on syscall entry.
*/
static inline void fp_user_discard(void)
{
/*
* If SME is active then exit streaming mode. If ZA is active
* then flush the SVE registers but leave userspace access to
* both SVE and SME enabled, otherwise disable SME for the
* task and fall through to disabling SVE too. This means
* that after a syscall we never have any streaming mode
* register state to track, if this changes the KVM code will
* need updating.
*/
if (system_supports_sme())
sme_smstop_sm();
if (!system_supports_sve())
return;
if (test_thread_flag(TIF_SVE)) {
unsigned int sve_vq_minus_one;
sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1;
sve_flush_live(true, sve_vq_minus_one);
}
}
UNHANDLED(el1t, 64, sync)
UNHANDLED(el1t, 64, irq)
UNHANDLED(el1t, 64, fiq)
@ -644,6 +673,8 @@ static void noinstr el0_svc(struct pt_regs *regs)
{
enter_from_user_mode(regs);
cortex_a76_erratum_1463225_svc_handler();
fp_user_discard();
local_daif_restore(DAIF_PROCCTX);
do_el0_svc(regs);
exit_to_user_mode(regs);
}
@ -783,6 +814,7 @@ static void noinstr el0_svc_compat(struct pt_regs *regs)
{
enter_from_user_mode(regs);
cortex_a76_erratum_1463225_svc_handler();
local_daif_restore(DAIF_PROCCTX);
do_el0_svc_compat(regs);
exit_to_user_mode(regs);
}

33
arch/arm64/kernel/syscall.c
View File

@ -8,7 +8,6 @@
#include <linux/randomize_kstack.h>
#include <linux/syscalls.h>
#include <asm/daifflags.h>
#include <asm/debug-monitors.h>
#include <asm/exception.h>
#include <asm/fpsimd.h>
@ -101,8 +100,6 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
* (Similarly for HVC and SMC elsewhere.)
*/
local_daif_restore(DAIF_PROCCTX);
if (flags & _TIF_MTE_ASYNC_FAULT) {
/*
* Process the asynchronous tag check fault before the actual
@ -153,38 +150,8 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
syscall_trace_exit(regs);
}
/*
* As per the ABI exit SME streaming mode and clear the SVE state not
* shared with FPSIMD on syscall entry.
*/
static inline void fp_user_discard(void)
{
/*
* If SME is active then exit streaming mode. If ZA is active
* then flush the SVE registers but leave userspace access to
* both SVE and SME enabled, otherwise disable SME for the
* task and fall through to disabling SVE too. This means
* that after a syscall we never have any streaming mode
* register state to track, if this changes the KVM code will
* need updating.
*/
if (system_supports_sme())
sme_smstop_sm();
if (!system_supports_sve())
return;
if (test_thread_flag(TIF_SVE)) {
unsigned int sve_vq_minus_one;
sve_vq_minus_one = sve_vq_from_vl(task_get_sve_vl(current)) - 1;
sve_flush_live(true, sve_vq_minus_one);
}
}
void do_el0_svc(struct pt_regs *regs)
{
fp_user_discard();
el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table);
}