Generic way to track the land vma area.
As a bonus, after unmapping sigpage, kernel won't try to land on its
previous position.
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
arch/mips/Kconfig | 1 +
arch/mips/kernel/signal.c | 11 +++++++----
arch/mips/kernel/vdso.c | 2 +-
arch/mips/vdso/genvdso.c | 8 --------
4 files changed, 9 insertions(+), 13 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 5e696ab80df4..eedb1683ec8e 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -10,6 +10,7 @@ config MIPS
select ARCH_HAS_SETUP_ADDITIONAL_PAGES
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select ARCH_HAS_USER_LANDING
select ARCH_SUPPORTS_UPROBES
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f1e985109da0..eb79272d3cc2 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -806,11 +806,13 @@ struct mips_abi mips_abi = {
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
+ unsigned long land = (unsigned long)current->mm->user_landing;
sigset_t *oldset = sigmask_to_save();
- int ret;
+ int ret = 1;
struct mips_abi *abi = current->thread.abi;
- void *vdso = current->mm->context.vdso;
+ if (land == UNMAPPED_USER_LANDING)
+ goto err;
/*
* If we were emulating a delay slot instruction, exit that frame such
* that addresses in the sigframe are as expected for userland and we
@@ -843,12 +845,13 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
rseq_signal_deliver(ksig, regs);
if (sig_uses_siginfo(&ksig->ka, abi))
- ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
+ ret = abi->setup_rt_frame(land + abi->vdso->off_rt_sigreturn,
ksig, regs, oldset);
else
- ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
+ ret = abi->setup_frame(land + abi->vdso->off_sigreturn,
ksig, regs, oldset);
+err:
signal_setup_done(ret, ksig, 0);
}
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index a4a321252df6..5523ba25ab3d 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -183,7 +183,7 @@ int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
goto out;
}
- mm->context.vdso = (void *)vdso_addr;
+ mm->user_landing = (void __user *)vdso_addr;
*sysinfo_ehdr = vdso_addr;
ret = 0;
diff --git a/arch/mips/vdso/genvdso.c b/arch/mips/vdso/genvdso.c
index 0303d30cde03..8f581a2c8578 100644
--- a/arch/mips/vdso/genvdso.c
+++ b/arch/mips/vdso/genvdso.c
@@ -259,13 +259,6 @@ int main(int argc, char **argv)
fprintf(out_file, "#include <linux/linkage.h>\n");
fprintf(out_file, "#include <linux/mm.h>\n");
fprintf(out_file, "#include <asm/vdso.h>\n");
- fprintf(out_file, "static void vdso_mremap(\n");
- fprintf(out_file, " const struct vm_special_mapping *sm,\n");
- fprintf(out_file, " struct vm_area_struct *new_vma)\n");
- fprintf(out_file, "{\n");
- fprintf(out_file, " current->mm->context.vdso =\n");
- fprintf(out_file, " (void *)(new_vma->vm_start);\n");
- fprintf(out_file, "}\n");
/* Write out the stripped VDSO data. */
fprintf(out_file,
@@ -290,7 +283,6 @@ int main(int argc, char **argv)
fprintf(out_file, "\t.mapping = {\n");
fprintf(out_file, "\t\t.name = \"[vdso]\",\n");
fprintf(out_file, "\t\t.pages = vdso_pages,\n");
- fprintf(out_file, "\t\t.mremap = vdso_mremap,\n");
fprintf(out_file, "\t},\n");
/* Calculate and write symbol offsets to <output file> */
--
2.28.0
