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arm64: add POE signal support

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Add PKEY support to signals, by saving and restoring POR_EL0 from the stackframe.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20240822151113.1479789-20-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Joey Gouly 2024-08-22 16:11:02 +01:00 committed by Will Deacon
parent 7f955be9f8
commit 9160f7e909
2 changed files with 69 additions and 0 deletions
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7
arch/arm64/include/uapi/asm/sigcontext.h
View File

@ -98,6 +98,13 @@ struct esr_context {
__u64 esr;
};
#define POE_MAGIC 0x504f4530
struct poe_context {
struct _aarch64_ctx head;
__u64 por_el0;
};
/*
* extra_context: describes extra space in the signal frame for
* additional structures that don't fit in sigcontext.__reserved[].

62
arch/arm64/kernel/signal.c
View File

@ -61,6 +61,7 @@ struct rt_sigframe_user_layout {
unsigned long za_offset;
unsigned long zt_offset;
unsigned long fpmr_offset;
unsigned long poe_offset;
unsigned long extra_offset;
unsigned long end_offset;
};
@ -185,6 +186,8 @@ struct user_ctxs {
u32 zt_size;
struct fpmr_context __user *fpmr;
u32 fpmr_size;
struct poe_context __user *poe;
u32 poe_size;
};
static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
@ -258,6 +261,32 @@ static int restore_fpmr_context(struct user_ctxs *user)
return err;
}
static int preserve_poe_context(struct poe_context __user *ctx)
{
int err = 0;
__put_user_error(POE_MAGIC, &ctx->head.magic, err);
__put_user_error(sizeof(*ctx), &ctx->head.size, err);
__put_user_error(read_sysreg_s(SYS_POR_EL0), &ctx->por_el0, err);
return err;
}
static int restore_poe_context(struct user_ctxs *user)
{
u64 por_el0;
int err = 0;
if (user->poe_size != sizeof(*user->poe))
return -EINVAL;
__get_user_error(por_el0, &(user->poe->por_el0), err);
if (!err)
write_sysreg_s(por_el0, SYS_POR_EL0);
return err;
}
#ifdef CONFIG_ARM64_SVE
static int preserve_sve_context(struct sve_context __user *ctx)
@ -621,6 +650,7 @@ static int parse_user_sigframe(struct user_ctxs *user,
user->za = NULL;
user->zt = NULL;
user->fpmr = NULL;
user->poe = NULL;
if (!IS_ALIGNED((unsigned long)base, 16))
goto invalid;
@ -671,6 +701,17 @@ static int parse_user_sigframe(struct user_ctxs *user,
/* ignore */
break;
case POE_MAGIC:
if (!system_supports_poe())
goto invalid;
if (user->poe)
goto invalid;
user->poe = (struct poe_context __user *)head;
user->poe_size = size;
break;
case SVE_MAGIC:
if (!system_supports_sve() && !system_supports_sme())
goto invalid;
@ -857,6 +898,9 @@ static int restore_sigframe(struct pt_regs *regs,
if (err == 0 && system_supports_sme2() && user.zt)
err = restore_zt_context(&user);
if (err == 0 && system_supports_poe() && user.poe)
err = restore_poe_context(&user);
return err;
}
@ -980,6 +1024,13 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
return err;
}
if (system_supports_poe()) {
err = sigframe_alloc(user, &user->poe_offset,
sizeof(struct poe_context));
if (err)
return err;
}
return sigframe_alloc_end(user);
}
@ -1042,6 +1093,14 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user,
err |= preserve_fpmr_context(fpmr_ctx);
}
if (system_supports_poe() && err == 0 && user->poe_offset) {
struct poe_context __user *poe_ctx =
apply_user_offset(user, user->poe_offset);
err |= preserve_poe_context(poe_ctx);
}
/* ZA state if present */
if (system_supports_sme() && err == 0 && user->za_offset) {
struct za_context __user *za_ctx =
@ -1178,6 +1237,9 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
sme_smstop();
}
if (system_supports_poe())
write_sysreg_s(POR_EL0_INIT, SYS_POR_EL0);
if (ka->sa.sa_flags & SA_RESTORER)
sigtramp = ka->sa.sa_restorer;
else