Generic way to track the landing vma area.
As a bonus, after unmapping sigpage, kernel won't try to land on its
previous position (due to UNMAPPED_VDSO_BASE check instead of
context.vdso ?= 0 check).
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/mmu.h | 2 --
arch/mips/kernel/signal.c | 11 +++++++----
arch/mips/kernel/vdso.c | 2 +-
arch/mips/vdso/genvdso.c | 8 --------
5 files changed, 9 insertions(+), 15 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 81096dd2c1ef..2bab0844f64b 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -12,6 +12,7 @@ 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_VDSO_BASE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_KEEP_MEMBLOCK
select ARCH_SUPPORTS_UPROBES
diff --git a/arch/mips/include/asm/mmu.h b/arch/mips/include/asm/mmu.h
index 5df0238f639b..928346a44eaf 100644
--- a/arch/mips/include/asm/mmu.h
+++ b/arch/mips/include/asm/mmu.h
@@ -12,8 +12,6 @@ typedef struct {
atomic64_t mmid;
};
- void *vdso;
-
/* lock to be held whilst modifying fp_bd_emupage_allocmap */
spinlock_t bd_emupage_lock;
/* bitmap tracking allocation of fp_bd_emupage */
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f1e985109da0..e0beaf2cdc0f 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)
{
+ void *land = (void *)current->mm->vdso_base;
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 == (void *)UNMAPPED_VDSO_BASE)
+ 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 9b2e1d2250b4..3f76417e5aed 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -184,7 +184,7 @@ int arch_setup_additional_pages(unsigned long *sysinfo_ehdr)
goto out;
}
- mm->context.vdso = (void *)vdso_addr;
+ mm->vdso_base = (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> */
--
2.31.1
